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IP subnet calculator

Type an address with its prefix or mask to see the network, its usable range and masks. Split it into smaller subnets, or look up any prefix in the reference tables.

Network232.128.0.0/11
Usable hosts2,097,150
Subnet mask255.224.0.0
Addresses2,097,152
Network address
232.128.0.0
Broadcast address
232.159.255.255
First usable
232.128.0.1
Last usable
232.159.255.254
Usable hosts
2,097,150 (2,097,152 less the network and broadcast addresses)
Subnet mask
255.224.0.0
Wildcard mask
0.31.255.255 (Cisco ACLs, OSPF)
Prefix length
/11
Type
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex E8800000 · Integer 3900702720 to 3902799871
Reverse DNS zones
128.232.in-addr.arpa
129.232.in-addr.arpa
130.232.in-addr.arpa
131.232.in-addr.arpa
132.232.in-addr.arpa
133.232.in-addr.arpa
134.232.in-addr.arpa
135.232.in-addr.arpa
136.232.in-addr.arpa
137.232.in-addr.arpa
138.232.in-addr.arpa
139.232.in-addr.arpa
140.232.in-addr.arpa
141.232.in-addr.arpa
142.232.in-addr.arpa
143.232.in-addr.arpa
and 16 more
/11 is not on a 8-bit boundary, so it takes 32 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11101000.10000000.00000000.00000000232.128.0.0
Subnet mask11111111.11100000.00000000.00000000255.224.0.0
Network11101000.10000000.00000000.00000000232.128.0.0
Broadcast11101000.10011111.11111111.11111111232.159.255.255
Split into smaller subnets/20
/12 (2)/13 (4)/14 (8)/15 (16)/16 (32)/17 (64)/18 (128)/19 (256)/20 (512)/21 (1,024)/22 (2,048)/23 (4,096)

232.128.0.0/11 makes 512 subnets of /20; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1232.128.0.0/20232.128.0.1 to 232.128.15.254232.128.15.2554,094
2232.128.16.0/20232.128.16.1 to 232.128.31.254232.128.31.2554,094
3232.128.32.0/20232.128.32.1 to 232.128.47.254232.128.47.2554,094
4232.128.48.0/20232.128.48.1 to 232.128.63.254232.128.63.2554,094
5232.128.64.0/20232.128.64.1 to 232.128.79.254232.128.79.2554,094
6232.128.80.0/20232.128.80.1 to 232.128.95.254232.128.95.2554,094
7232.128.96.0/20232.128.96.1 to 232.128.111.254232.128.111.2554,094
8232.128.112.0/20232.128.112.1 to 232.128.127.254232.128.127.2554,094
9232.128.128.0/20232.128.128.1 to 232.128.143.254232.128.143.2554,094
10232.128.144.0/20232.128.144.1 to 232.128.159.254232.128.159.2554,094
11232.128.160.0/20232.128.160.1 to 232.128.175.254232.128.175.2554,094
12232.128.176.0/20232.128.176.1 to 232.128.191.254232.128.191.2554,094
13232.128.192.0/20232.128.192.1 to 232.128.207.254232.128.207.2554,094
14232.128.208.0/20232.128.208.1 to 232.128.223.254232.128.223.2554,094
15232.128.224.0/20232.128.224.1 to 232.128.239.254232.128.239.2554,094
16232.128.240.0/20232.128.240.1 to 232.128.255.254232.128.255.2554,094
17232.129.0.0/20232.129.0.1 to 232.129.15.254232.129.15.2554,094
18232.129.16.0/20232.129.16.1 to 232.129.31.254232.129.31.2554,094
19232.129.32.0/20232.129.32.1 to 232.129.47.254232.129.47.2554,094
20232.129.48.0/20232.129.48.1 to 232.129.63.254232.129.63.2554,094
21232.129.64.0/20232.129.64.1 to 232.129.79.254232.129.79.2554,094
22232.129.80.0/20232.129.80.1 to 232.129.95.254232.129.95.2554,094
23232.129.96.0/20232.129.96.1 to 232.129.111.254232.129.111.2554,094
24232.129.112.0/20232.129.112.1 to 232.129.127.254232.129.127.2554,094
25232.129.128.0/20232.129.128.1 to 232.129.143.254232.129.143.2554,094
26232.129.144.0/20232.129.144.1 to 232.129.159.254232.129.159.2554,094
27232.129.160.0/20232.129.160.1 to 232.129.175.254232.129.175.2554,094
28232.129.176.0/20232.129.176.1 to 232.129.191.254232.129.191.2554,094
29232.129.192.0/20232.129.192.1 to 232.129.207.254232.129.207.2554,094
30232.129.208.0/20232.129.208.1 to 232.129.223.254232.129.223.2554,094
31232.129.224.0/20232.129.224.1 to 232.129.239.254232.129.239.2554,094
32232.129.240.0/20232.129.240.1 to 232.129.255.254232.129.255.2554,094
33232.130.0.0/20232.130.0.1 to 232.130.15.254232.130.15.2554,094
34232.130.16.0/20232.130.16.1 to 232.130.31.254232.130.31.2554,094
35232.130.32.0/20232.130.32.1 to 232.130.47.254232.130.47.2554,094
36232.130.48.0/20232.130.48.1 to 232.130.63.254232.130.63.2554,094
37232.130.64.0/20232.130.64.1 to 232.130.79.254232.130.79.2554,094
38232.130.80.0/20232.130.80.1 to 232.130.95.254232.130.95.2554,094
39232.130.96.0/20232.130.96.1 to 232.130.111.254232.130.111.2554,094
40232.130.112.0/20232.130.112.1 to 232.130.127.254232.130.127.2554,094
41232.130.128.0/20232.130.128.1 to 232.130.143.254232.130.143.2554,094
42232.130.144.0/20232.130.144.1 to 232.130.159.254232.130.159.2554,094
43232.130.160.0/20232.130.160.1 to 232.130.175.254232.130.175.2554,094
44232.130.176.0/20232.130.176.1 to 232.130.191.254232.130.191.2554,094
45232.130.192.0/20232.130.192.1 to 232.130.207.254232.130.207.2554,094
46232.130.208.0/20232.130.208.1 to 232.130.223.254232.130.223.2554,094
47232.130.224.0/20232.130.224.1 to 232.130.239.254232.130.239.2554,094
48232.130.240.0/20232.130.240.1 to 232.130.255.254232.130.255.2554,094
49232.131.0.0/20232.131.0.1 to 232.131.15.254232.131.15.2554,094
50232.131.16.0/20232.131.16.1 to 232.131.31.254232.131.31.2554,094
51232.131.32.0/20232.131.32.1 to 232.131.47.254232.131.47.2554,094
52232.131.48.0/20232.131.48.1 to 232.131.63.254232.131.63.2554,094
53232.131.64.0/20232.131.64.1 to 232.131.79.254232.131.79.2554,094
54232.131.80.0/20232.131.80.1 to 232.131.95.254232.131.95.2554,094
55232.131.96.0/20232.131.96.1 to 232.131.111.254232.131.111.2554,094
56232.131.112.0/20232.131.112.1 to 232.131.127.254232.131.127.2554,094
57232.131.128.0/20232.131.128.1 to 232.131.143.254232.131.143.2554,094
58232.131.144.0/20232.131.144.1 to 232.131.159.254232.131.159.2554,094
59232.131.160.0/20232.131.160.1 to 232.131.175.254232.131.175.2554,094
60232.131.176.0/20232.131.176.1 to 232.131.191.254232.131.191.2554,094
61232.131.192.0/20232.131.192.1 to 232.131.207.254232.131.207.2554,094
62232.131.208.0/20232.131.208.1 to 232.131.223.254232.131.223.2554,094
63232.131.224.0/20232.131.224.1 to 232.131.239.254232.131.239.2554,094
64232.131.240.0/20232.131.240.1 to 232.131.255.254232.131.255.2554,094
65232.132.0.0/20232.132.0.1 to 232.132.15.254232.132.15.2554,094
66232.132.16.0/20232.132.16.1 to 232.132.31.254232.132.31.2554,094
67232.132.32.0/20232.132.32.1 to 232.132.47.254232.132.47.2554,094
68232.132.48.0/20232.132.48.1 to 232.132.63.254232.132.63.2554,094
69232.132.64.0/20232.132.64.1 to 232.132.79.254232.132.79.2554,094
70232.132.80.0/20232.132.80.1 to 232.132.95.254232.132.95.2554,094
71232.132.96.0/20232.132.96.1 to 232.132.111.254232.132.111.2554,094
72232.132.112.0/20232.132.112.1 to 232.132.127.254232.132.127.2554,094
73232.132.128.0/20232.132.128.1 to 232.132.143.254232.132.143.2554,094
74232.132.144.0/20232.132.144.1 to 232.132.159.254232.132.159.2554,094
75232.132.160.0/20232.132.160.1 to 232.132.175.254232.132.175.2554,094
76232.132.176.0/20232.132.176.1 to 232.132.191.254232.132.191.2554,094
77232.132.192.0/20232.132.192.1 to 232.132.207.254232.132.207.2554,094
78232.132.208.0/20232.132.208.1 to 232.132.223.254232.132.223.2554,094
79232.132.224.0/20232.132.224.1 to 232.132.239.254232.132.239.2554,094
80232.132.240.0/20232.132.240.1 to 232.132.255.254232.132.255.2554,094
81232.133.0.0/20232.133.0.1 to 232.133.15.254232.133.15.2554,094
82232.133.16.0/20232.133.16.1 to 232.133.31.254232.133.31.2554,094
83232.133.32.0/20232.133.32.1 to 232.133.47.254232.133.47.2554,094
84232.133.48.0/20232.133.48.1 to 232.133.63.254232.133.63.2554,094
85232.133.64.0/20232.133.64.1 to 232.133.79.254232.133.79.2554,094
86232.133.80.0/20232.133.80.1 to 232.133.95.254232.133.95.2554,094
87232.133.96.0/20232.133.96.1 to 232.133.111.254232.133.111.2554,094
88232.133.112.0/20232.133.112.1 to 232.133.127.254232.133.127.2554,094
89232.133.128.0/20232.133.128.1 to 232.133.143.254232.133.143.2554,094
90232.133.144.0/20232.133.144.1 to 232.133.159.254232.133.159.2554,094
91232.133.160.0/20232.133.160.1 to 232.133.175.254232.133.175.2554,094
92232.133.176.0/20232.133.176.1 to 232.133.191.254232.133.191.2554,094
93232.133.192.0/20232.133.192.1 to 232.133.207.254232.133.207.2554,094
94232.133.208.0/20232.133.208.1 to 232.133.223.254232.133.223.2554,094
95232.133.224.0/20232.133.224.1 to 232.133.239.254232.133.239.2554,094
96232.133.240.0/20232.133.240.1 to 232.133.255.254232.133.255.2554,094
97232.134.0.0/20232.134.0.1 to 232.134.15.254232.134.15.2554,094
98232.134.16.0/20232.134.16.1 to 232.134.31.254232.134.31.2554,094
99232.134.32.0/20232.134.32.1 to 232.134.47.254232.134.47.2554,094
100232.134.48.0/20232.134.48.1 to 232.134.63.254232.134.63.2554,094
101232.134.64.0/20232.134.64.1 to 232.134.79.254232.134.79.2554,094
102232.134.80.0/20232.134.80.1 to 232.134.95.254232.134.95.2554,094
103232.134.96.0/20232.134.96.1 to 232.134.111.254232.134.111.2554,094
104232.134.112.0/20232.134.112.1 to 232.134.127.254232.134.127.2554,094
105232.134.128.0/20232.134.128.1 to 232.134.143.254232.134.143.2554,094
106232.134.144.0/20232.134.144.1 to 232.134.159.254232.134.159.2554,094
107232.134.160.0/20232.134.160.1 to 232.134.175.254232.134.175.2554,094
108232.134.176.0/20232.134.176.1 to 232.134.191.254232.134.191.2554,094
109232.134.192.0/20232.134.192.1 to 232.134.207.254232.134.207.2554,094
110232.134.208.0/20232.134.208.1 to 232.134.223.254232.134.223.2554,094
111232.134.224.0/20232.134.224.1 to 232.134.239.254232.134.239.2554,094
112232.134.240.0/20232.134.240.1 to 232.134.255.254232.134.255.2554,094
113232.135.0.0/20232.135.0.1 to 232.135.15.254232.135.15.2554,094
114232.135.16.0/20232.135.16.1 to 232.135.31.254232.135.31.2554,094
115232.135.32.0/20232.135.32.1 to 232.135.47.254232.135.47.2554,094
116232.135.48.0/20232.135.48.1 to 232.135.63.254232.135.63.2554,094
117232.135.64.0/20232.135.64.1 to 232.135.79.254232.135.79.2554,094
118232.135.80.0/20232.135.80.1 to 232.135.95.254232.135.95.2554,094
119232.135.96.0/20232.135.96.1 to 232.135.111.254232.135.111.2554,094
120232.135.112.0/20232.135.112.1 to 232.135.127.254232.135.127.2554,094
121232.135.128.0/20232.135.128.1 to 232.135.143.254232.135.143.2554,094
122232.135.144.0/20232.135.144.1 to 232.135.159.254232.135.159.2554,094
123232.135.160.0/20232.135.160.1 to 232.135.175.254232.135.175.2554,094
124232.135.176.0/20232.135.176.1 to 232.135.191.254232.135.191.2554,094
125232.135.192.0/20232.135.192.1 to 232.135.207.254232.135.207.2554,094
126232.135.208.0/20232.135.208.1 to 232.135.223.254232.135.223.2554,094
127232.135.224.0/20232.135.224.1 to 232.135.239.254232.135.239.2554,094
128232.135.240.0/20232.135.240.1 to 232.135.255.254232.135.255.2554,094
129232.136.0.0/20232.136.0.1 to 232.136.15.254232.136.15.2554,094
130232.136.16.0/20232.136.16.1 to 232.136.31.254232.136.31.2554,094
131232.136.32.0/20232.136.32.1 to 232.136.47.254232.136.47.2554,094
132232.136.48.0/20232.136.48.1 to 232.136.63.254232.136.63.2554,094
133232.136.64.0/20232.136.64.1 to 232.136.79.254232.136.79.2554,094
134232.136.80.0/20232.136.80.1 to 232.136.95.254232.136.95.2554,094
135232.136.96.0/20232.136.96.1 to 232.136.111.254232.136.111.2554,094
136232.136.112.0/20232.136.112.1 to 232.136.127.254232.136.127.2554,094
137232.136.128.0/20232.136.128.1 to 232.136.143.254232.136.143.2554,094
138232.136.144.0/20232.136.144.1 to 232.136.159.254232.136.159.2554,094
139232.136.160.0/20232.136.160.1 to 232.136.175.254232.136.175.2554,094
140232.136.176.0/20232.136.176.1 to 232.136.191.254232.136.191.2554,094
141232.136.192.0/20232.136.192.1 to 232.136.207.254232.136.207.2554,094
142232.136.208.0/20232.136.208.1 to 232.136.223.254232.136.223.2554,094
143232.136.224.0/20232.136.224.1 to 232.136.239.254232.136.239.2554,094
144232.136.240.0/20232.136.240.1 to 232.136.255.254232.136.255.2554,094
145232.137.0.0/20232.137.0.1 to 232.137.15.254232.137.15.2554,094
146232.137.16.0/20232.137.16.1 to 232.137.31.254232.137.31.2554,094
147232.137.32.0/20232.137.32.1 to 232.137.47.254232.137.47.2554,094
148232.137.48.0/20232.137.48.1 to 232.137.63.254232.137.63.2554,094
149232.137.64.0/20232.137.64.1 to 232.137.79.254232.137.79.2554,094
150232.137.80.0/20232.137.80.1 to 232.137.95.254232.137.95.2554,094
151232.137.96.0/20232.137.96.1 to 232.137.111.254232.137.111.2554,094
152232.137.112.0/20232.137.112.1 to 232.137.127.254232.137.127.2554,094
153232.137.128.0/20232.137.128.1 to 232.137.143.254232.137.143.2554,094
154232.137.144.0/20232.137.144.1 to 232.137.159.254232.137.159.2554,094
155232.137.160.0/20232.137.160.1 to 232.137.175.254232.137.175.2554,094
156232.137.176.0/20232.137.176.1 to 232.137.191.254232.137.191.2554,094
157232.137.192.0/20232.137.192.1 to 232.137.207.254232.137.207.2554,094
158232.137.208.0/20232.137.208.1 to 232.137.223.254232.137.223.2554,094
159232.137.224.0/20232.137.224.1 to 232.137.239.254232.137.239.2554,094
160232.137.240.0/20232.137.240.1 to 232.137.255.254232.137.255.2554,094
161232.138.0.0/20232.138.0.1 to 232.138.15.254232.138.15.2554,094
162232.138.16.0/20232.138.16.1 to 232.138.31.254232.138.31.2554,094
163232.138.32.0/20232.138.32.1 to 232.138.47.254232.138.47.2554,094
164232.138.48.0/20232.138.48.1 to 232.138.63.254232.138.63.2554,094
165232.138.64.0/20232.138.64.1 to 232.138.79.254232.138.79.2554,094
166232.138.80.0/20232.138.80.1 to 232.138.95.254232.138.95.2554,094
167232.138.96.0/20232.138.96.1 to 232.138.111.254232.138.111.2554,094
168232.138.112.0/20232.138.112.1 to 232.138.127.254232.138.127.2554,094
169232.138.128.0/20232.138.128.1 to 232.138.143.254232.138.143.2554,094
170232.138.144.0/20232.138.144.1 to 232.138.159.254232.138.159.2554,094
171232.138.160.0/20232.138.160.1 to 232.138.175.254232.138.175.2554,094
172232.138.176.0/20232.138.176.1 to 232.138.191.254232.138.191.2554,094
173232.138.192.0/20232.138.192.1 to 232.138.207.254232.138.207.2554,094
174232.138.208.0/20232.138.208.1 to 232.138.223.254232.138.223.2554,094
175232.138.224.0/20232.138.224.1 to 232.138.239.254232.138.239.2554,094
176232.138.240.0/20232.138.240.1 to 232.138.255.254232.138.255.2554,094
177232.139.0.0/20232.139.0.1 to 232.139.15.254232.139.15.2554,094
178232.139.16.0/20232.139.16.1 to 232.139.31.254232.139.31.2554,094
179232.139.32.0/20232.139.32.1 to 232.139.47.254232.139.47.2554,094
180232.139.48.0/20232.139.48.1 to 232.139.63.254232.139.63.2554,094
181232.139.64.0/20232.139.64.1 to 232.139.79.254232.139.79.2554,094
182232.139.80.0/20232.139.80.1 to 232.139.95.254232.139.95.2554,094
183232.139.96.0/20232.139.96.1 to 232.139.111.254232.139.111.2554,094
184232.139.112.0/20232.139.112.1 to 232.139.127.254232.139.127.2554,094
185232.139.128.0/20232.139.128.1 to 232.139.143.254232.139.143.2554,094
186232.139.144.0/20232.139.144.1 to 232.139.159.254232.139.159.2554,094
187232.139.160.0/20232.139.160.1 to 232.139.175.254232.139.175.2554,094
188232.139.176.0/20232.139.176.1 to 232.139.191.254232.139.191.2554,094
189232.139.192.0/20232.139.192.1 to 232.139.207.254232.139.207.2554,094
190232.139.208.0/20232.139.208.1 to 232.139.223.254232.139.223.2554,094
191232.139.224.0/20232.139.224.1 to 232.139.239.254232.139.239.2554,094
192232.139.240.0/20232.139.240.1 to 232.139.255.254232.139.255.2554,094
193232.140.0.0/20232.140.0.1 to 232.140.15.254232.140.15.2554,094
194232.140.16.0/20232.140.16.1 to 232.140.31.254232.140.31.2554,094
195232.140.32.0/20232.140.32.1 to 232.140.47.254232.140.47.2554,094
196232.140.48.0/20232.140.48.1 to 232.140.63.254232.140.63.2554,094
197232.140.64.0/20232.140.64.1 to 232.140.79.254232.140.79.2554,094
198232.140.80.0/20232.140.80.1 to 232.140.95.254232.140.95.2554,094
199232.140.96.0/20232.140.96.1 to 232.140.111.254232.140.111.2554,094
200232.140.112.0/20232.140.112.1 to 232.140.127.254232.140.127.2554,094
201232.140.128.0/20232.140.128.1 to 232.140.143.254232.140.143.2554,094
202232.140.144.0/20232.140.144.1 to 232.140.159.254232.140.159.2554,094
203232.140.160.0/20232.140.160.1 to 232.140.175.254232.140.175.2554,094
204232.140.176.0/20232.140.176.1 to 232.140.191.254232.140.191.2554,094
205232.140.192.0/20232.140.192.1 to 232.140.207.254232.140.207.2554,094
206232.140.208.0/20232.140.208.1 to 232.140.223.254232.140.223.2554,094
207232.140.224.0/20232.140.224.1 to 232.140.239.254232.140.239.2554,094
208232.140.240.0/20232.140.240.1 to 232.140.255.254232.140.255.2554,094
209232.141.0.0/20232.141.0.1 to 232.141.15.254232.141.15.2554,094
210232.141.16.0/20232.141.16.1 to 232.141.31.254232.141.31.2554,094
211232.141.32.0/20232.141.32.1 to 232.141.47.254232.141.47.2554,094
212232.141.48.0/20232.141.48.1 to 232.141.63.254232.141.63.2554,094
213232.141.64.0/20232.141.64.1 to 232.141.79.254232.141.79.2554,094
214232.141.80.0/20232.141.80.1 to 232.141.95.254232.141.95.2554,094
215232.141.96.0/20232.141.96.1 to 232.141.111.254232.141.111.2554,094
216232.141.112.0/20232.141.112.1 to 232.141.127.254232.141.127.2554,094
217232.141.128.0/20232.141.128.1 to 232.141.143.254232.141.143.2554,094
218232.141.144.0/20232.141.144.1 to 232.141.159.254232.141.159.2554,094
219232.141.160.0/20232.141.160.1 to 232.141.175.254232.141.175.2554,094
220232.141.176.0/20232.141.176.1 to 232.141.191.254232.141.191.2554,094
221232.141.192.0/20232.141.192.1 to 232.141.207.254232.141.207.2554,094
222232.141.208.0/20232.141.208.1 to 232.141.223.254232.141.223.2554,094
223232.141.224.0/20232.141.224.1 to 232.141.239.254232.141.239.2554,094
224232.141.240.0/20232.141.240.1 to 232.141.255.254232.141.255.2554,094
225232.142.0.0/20232.142.0.1 to 232.142.15.254232.142.15.2554,094
226232.142.16.0/20232.142.16.1 to 232.142.31.254232.142.31.2554,094
227232.142.32.0/20232.142.32.1 to 232.142.47.254232.142.47.2554,094
228232.142.48.0/20232.142.48.1 to 232.142.63.254232.142.63.2554,094
229232.142.64.0/20232.142.64.1 to 232.142.79.254232.142.79.2554,094
230232.142.80.0/20232.142.80.1 to 232.142.95.254232.142.95.2554,094
231232.142.96.0/20232.142.96.1 to 232.142.111.254232.142.111.2554,094
232232.142.112.0/20232.142.112.1 to 232.142.127.254232.142.127.2554,094
233232.142.128.0/20232.142.128.1 to 232.142.143.254232.142.143.2554,094
234232.142.144.0/20232.142.144.1 to 232.142.159.254232.142.159.2554,094
235232.142.160.0/20232.142.160.1 to 232.142.175.254232.142.175.2554,094
236232.142.176.0/20232.142.176.1 to 232.142.191.254232.142.191.2554,094
237232.142.192.0/20232.142.192.1 to 232.142.207.254232.142.207.2554,094
238232.142.208.0/20232.142.208.1 to 232.142.223.254232.142.223.2554,094
239232.142.224.0/20232.142.224.1 to 232.142.239.254232.142.239.2554,094
240232.142.240.0/20232.142.240.1 to 232.142.255.254232.142.255.2554,094
241232.143.0.0/20232.143.0.1 to 232.143.15.254232.143.15.2554,094
242232.143.16.0/20232.143.16.1 to 232.143.31.254232.143.31.2554,094
243232.143.32.0/20232.143.32.1 to 232.143.47.254232.143.47.2554,094
244232.143.48.0/20232.143.48.1 to 232.143.63.254232.143.63.2554,094
245232.143.64.0/20232.143.64.1 to 232.143.79.254232.143.79.2554,094
246232.143.80.0/20232.143.80.1 to 232.143.95.254232.143.95.2554,094
247232.143.96.0/20232.143.96.1 to 232.143.111.254232.143.111.2554,094
248232.143.112.0/20232.143.112.1 to 232.143.127.254232.143.127.2554,094
249232.143.128.0/20232.143.128.1 to 232.143.143.254232.143.143.2554,094
250232.143.144.0/20232.143.144.1 to 232.143.159.254232.143.159.2554,094
251232.143.160.0/20232.143.160.1 to 232.143.175.254232.143.175.2554,094
252232.143.176.0/20232.143.176.1 to 232.143.191.254232.143.191.2554,094
253232.143.192.0/20232.143.192.1 to 232.143.207.254232.143.207.2554,094
254232.143.208.0/20232.143.208.1 to 232.143.223.254232.143.223.2554,094
255232.143.224.0/20232.143.224.1 to 232.143.239.254232.143.239.2554,094
256232.143.240.0/20232.143.240.1 to 232.143.255.254232.143.255.2554,094

IPv4 CIDR reference (/0 to /32)

IPv4 prefix lengths
PrefixSubnet maskWildcardAddressesUsable hostsSizeTypical use
/00.0.0.0255.255.255.2554,294,967,2964,294,967,29416,777,216 × /24
/1128.0.0.0127.255.255.2552,147,483,6482,147,483,6468,388,608 × /24
/2192.0.0.063.255.255.2551,073,741,8241,073,741,8224,194,304 × /24
/3224.0.0.031.255.255.255536,870,912536,870,9102,097,152 × /24
/4240.0.0.015.255.255.255268,435,456268,435,4541,048,576 × /24
/5248.0.0.07.255.255.255134,217,728134,217,726524,288 × /24
/6252.0.0.03.255.255.25567,108,86467,108,862262,144 × /24
/7254.0.0.01.255.255.25533,554,43233,554,430131,072 × /24
/8255.0.0.00.255.255.25516,777,21616,777,21465,536 × /24Old class A; 10.0.0.0/8
/9255.128.0.00.127.255.2558,388,6088,388,60632,768 × /24
/10255.192.0.00.63.255.2554,194,3044,194,30216,384 × /24
/11255.224.0.00.31.255.2552,097,1522,097,1508,192 × /24
/12255.240.0.00.15.255.2551,048,5761,048,5744,096 × /24172.16.0.0/12
/13255.248.0.00.7.255.255524,288524,2862,048 × /24
/14255.252.0.00.3.255.255262,144262,1421,024 × /24
/15255.254.0.00.1.255.255131,072131,070512 × /24
/16255.255.0.00.0.255.25565,53665,534256 × /24Old class B; 192.168.0.0/16
/17255.255.128.00.0.127.25532,76832,766128 × /24
/18255.255.192.00.0.63.25516,38416,38264 × /24
/19255.255.224.00.0.31.2558,1928,19032 × /24
/20255.255.240.00.0.15.2554,0964,09416 × /24
/21255.255.248.00.0.7.2552,0482,0468 × /24
/22255.255.252.00.0.3.2551,0241,0224 × /24Large office or guest Wi-Fi (1,022 hosts)
/23255.255.254.00.0.1.2555125102 × /24Larger office LAN (510 hosts)
/24255.255.255.00.0.0.2552562541 × /24Typical office LAN (old class C)
/25255.255.255.1280.0.0.1271281261/2 of a /24Smaller LAN or VLAN
/26255.255.255.1920.0.0.6364621/4 of a /24Smaller LAN or VLAN
/27255.255.255.2240.0.0.3132301/8 of a /24Small VLAN, phones, cameras
/28255.255.255.2400.0.0.1516141/16 of a /24Small VLAN, phones, cameras
/29255.255.255.2480.0.0.7861/32 of a /24Small fixed public block (5 usable)
/30255.255.255.2520.0.0.3421/64 of a /24Point-to-point (old style)
/31255.255.255.2540.0.0.1221/128 of a /24Point-to-point link (RFC 3021)
/32255.255.255.2550.0.0.0111/256 of a /24One host

IPv6 prefix reference

IPv6 prefix lengths
PrefixAddresses/64 LANs/48 sitesNibbleTypical use
/342,535,295,865,117,307,932,921,825,928,971,026,432 (2^125)2,305,843,009,213,693,95235,184,372,088,832NoAll global unicast (2000::/3)
/165,192,296,858,534,827,628,530,496,329,220,096 (2^112)281,474,976,710,6564,294,967,296Yes
/20324,518,553,658,426,726,783,156,020,576,256 (2^108)17,592,186,044,416268,435,456YesLarge provider allocation (RIPE minimum for some)
/29633,825,300,114,114,700,748,351,602,688 (2^99)34,359,738,368524,288NoRIPE allocation to a provider (often)
/3279,228,162,514,264,337,593,543,950,336 (2^96)4,294,967,29665,536YesProvider allocation (RIPE default)
/364,951,760,157,141,521,099,596,496,896 (2^92)268,435,4564,096Yes
/40309,485,009,821,345,068,724,781,056 (2^88)16,777,216256Yes
/4419,342,813,113,834,066,795,298,816 (2^84)1,048,57616Yes
/481,208,925,819,614,629,174,706,176 (2^80)65,5361YesOne site or organisation (RIPE PI / assignment)
/5275,557,863,725,914,323,419,136 (2^76)4,096Yes
/564,722,366,482,869,645,213,696 (2^72)256YesSmall site or home (common provider assignment)
/60295,147,905,179,352,825,856 (2^68)16YesSome home broadband (16 LANs)
/6418,446,744,073,709,551,616 (2^64)1YesOne LAN or VLAN (needed for SLAAC)
/7272,057,594,037,927,936 (2^56)1/256 of a /64Yes
/80281,474,976,710,656 (2^48)1/65,536 of a /64Yes
/964,294,967,2961/4,294,967,296 of a /64YesEmbeds an IPv4 address (NAT64)
/11265,5361/281,474,976,710,656 of a /64Yes
/1202561/72,057,594,037,927,936 of a /64Yes
/124161/1,152,921,504,606,846,976 of a /64Yes
/12641/4,611,686,018,427,387,904 of a /64No
/12721/9,223,372,036,854,775,808 of a /64NoPoint-to-point link (RFC 6164)
/12811/18,446,744,073,709,551,616 of a /64YesOne host or loopback

Private and special ranges

IPv4

Special-purpose ranges
RangeNameWhat it is
255.255.255.255/32Limited broadcastEvery host on the local network
0.0.0.0/8This networkNot routed; 0.0.0.0 means "any address" in settings
10.0.0.0/8Private (RFC 1918)Office and home networks; not routed on the internet
100.64.0.0/10Shared address space (CGNAT)Used by providers behind carrier-grade NAT (RFC 6598)
127.0.0.0/8LoopbackThis computer
169.254.0.0/16Link-local (APIPA)Self-assigned when no DHCP server answers
172.16.0.0/12Private (RFC 1918)Office and home networks; not routed on the internet
192.0.0.0/24IETF protocol assignmentsSpecial uses such as DS-Lite
192.0.2.0/24Documentation (TEST-NET-1)For examples; never used on a network
192.88.99.0/246to4 relay (deprecated)Formerly anycast for 6to4
192.168.0.0/16Private (RFC 1918)Office and home networks; not routed on the internet
198.18.0.0/15BenchmarkingNetwork equipment testing (RFC 2544)
198.51.100.0/24Documentation (TEST-NET-2)For examples; never used on a network
203.0.113.0/24Documentation (TEST-NET-3)For examples; never used on a network
224.0.0.0/4MulticastOne-to-many traffic, such as IPTV and routing protocols
240.0.0.0/4ReservedFuture use; not usable on most systems

IPv6

Special-purpose ranges
RangeNameWhat it is
::/128UnspecifiedNo address; :: means "any address" in settings
::1/128LoopbackThis computer
::ffff:0:0/96IPv4-mappedAn IPv4 address written as IPv6
64:ff9b::/96NAT64IPv4 addresses reached through a NAT64 gateway
100::/64Discard onlyTraffic sent here is dropped (RFC 6666)
2001:db8::/32DocumentationFor examples; never used on a network
2001::/32TeredoIPv6 tunnelled over IPv4 UDP
2002::/166to4IPv6 tunnelled over IPv4 (largely retired)
3fff::/20DocumentationFor examples (RFC 9637)
fc00::/7Unique local (ULA)Private IPv6, like RFC 1918; usually fd00::/8
fe80::/10Link-localEvery IPv6 interface has one; not routed
ff00::/8MulticastOne-to-many traffic; replaces broadcast
2000::/3Global unicastPublic internet addresses

About this tool

A network is written as an address and a prefix length, such as 192.168.1.0/24: the first 24 bits name the network and the rest number the devices on it. The calculator works out where the network starts and ends, how many devices it holds, its subnet and wildcard masks, and the reverse DNS zone to ask your provider for.

It also splits a network into equal smaller ones (one per VLAN or site), turns a range of addresses into the fewest CIDR blocks for a firewall rule, and lists every IPv4 prefix length and the common IPv6 ones in reference tables.

Common questions

Why are two addresses lost in every IPv4 subnet?

The first address names the network and the last is the broadcast address, so a /24 has 256 addresses but 254 for devices. A /31 (a link between two routers) and a /32 (one host) are the exceptions.

What size of IPv6 network should a LAN use?

Always /64. Devices pick their own address within it (SLAAC), which needs the full 64 bits. A site usually gets a /48 or /56 from its provider, which holds 65,536 or 256 LANs.

What is a wildcard mask?

The subnet mask turned inside out: 255.255.255.0 becomes 0.0.0.255. Cisco access lists and OSPF use it to say which bits must match.

Which ranges can I use inside an office?

IPv4: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. IPv6: unique local addresses from fd00::/8, though most networks use the public prefix from their provider.