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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.

Network241.80.0.0/12
Usable hosts1,048,574
Subnet mask255.240.0.0
Addresses1,048,576
Network address
241.80.0.0
Broadcast address
241.95.255.255
First usable
241.80.0.1
Last usable
241.95.255.254
Usable hosts
1,048,574 (1,048,576 less the network and broadcast addresses)
Subnet mask
255.240.0.0
Wildcard mask
0.15.255.255 (Cisco ACLs, OSPF)
Prefix length
/12
Type
Reserved 240.0.0.0/4
Future use; not usable on most systems
Old class
E (reserved)
As numbers
Hex F1500000 · Integer 4048551936 to 4049600511
Reverse DNS zones
80.241.in-addr.arpa
81.241.in-addr.arpa
82.241.in-addr.arpa
83.241.in-addr.arpa
84.241.in-addr.arpa
85.241.in-addr.arpa
86.241.in-addr.arpa
87.241.in-addr.arpa
88.241.in-addr.arpa
89.241.in-addr.arpa
90.241.in-addr.arpa
91.241.in-addr.arpa
92.241.in-addr.arpa
93.241.in-addr.arpa
94.241.in-addr.arpa
95.241.in-addr.arpa
/12 is not on a 8-bit boundary, so it takes 16 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11110001.01010000.00000000.00000000241.80.0.0
Subnet mask11111111.11110000.00000000.00000000255.240.0.0
Network11110001.01010000.00000000.00000000241.80.0.0
Broadcast11110001.01011111.11111111.11111111241.95.255.255
Split into smaller subnets/20
/13 (2)/14 (4)/15 (8)/16 (16)/17 (32)/18 (64)/19 (128)/20 (256)/21 (512)/22 (1,024)/23 (2,048)/24 (4,096)

241.80.0.0/12 makes 256 subnets of /20.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1241.80.0.0/20241.80.0.1 to 241.80.15.254241.80.15.2554,094
2241.80.16.0/20241.80.16.1 to 241.80.31.254241.80.31.2554,094
3241.80.32.0/20241.80.32.1 to 241.80.47.254241.80.47.2554,094
4241.80.48.0/20241.80.48.1 to 241.80.63.254241.80.63.2554,094
5241.80.64.0/20241.80.64.1 to 241.80.79.254241.80.79.2554,094
6241.80.80.0/20241.80.80.1 to 241.80.95.254241.80.95.2554,094
7241.80.96.0/20241.80.96.1 to 241.80.111.254241.80.111.2554,094
8241.80.112.0/20241.80.112.1 to 241.80.127.254241.80.127.2554,094
9241.80.128.0/20241.80.128.1 to 241.80.143.254241.80.143.2554,094
10241.80.144.0/20241.80.144.1 to 241.80.159.254241.80.159.2554,094
11241.80.160.0/20241.80.160.1 to 241.80.175.254241.80.175.2554,094
12241.80.176.0/20241.80.176.1 to 241.80.191.254241.80.191.2554,094
13241.80.192.0/20241.80.192.1 to 241.80.207.254241.80.207.2554,094
14241.80.208.0/20241.80.208.1 to 241.80.223.254241.80.223.2554,094
15241.80.224.0/20241.80.224.1 to 241.80.239.254241.80.239.2554,094
16241.80.240.0/20241.80.240.1 to 241.80.255.254241.80.255.2554,094
17241.81.0.0/20241.81.0.1 to 241.81.15.254241.81.15.2554,094
18241.81.16.0/20241.81.16.1 to 241.81.31.254241.81.31.2554,094
19241.81.32.0/20241.81.32.1 to 241.81.47.254241.81.47.2554,094
20241.81.48.0/20241.81.48.1 to 241.81.63.254241.81.63.2554,094
21241.81.64.0/20241.81.64.1 to 241.81.79.254241.81.79.2554,094
22241.81.80.0/20241.81.80.1 to 241.81.95.254241.81.95.2554,094
23241.81.96.0/20241.81.96.1 to 241.81.111.254241.81.111.2554,094
24241.81.112.0/20241.81.112.1 to 241.81.127.254241.81.127.2554,094
25241.81.128.0/20241.81.128.1 to 241.81.143.254241.81.143.2554,094
26241.81.144.0/20241.81.144.1 to 241.81.159.254241.81.159.2554,094
27241.81.160.0/20241.81.160.1 to 241.81.175.254241.81.175.2554,094
28241.81.176.0/20241.81.176.1 to 241.81.191.254241.81.191.2554,094
29241.81.192.0/20241.81.192.1 to 241.81.207.254241.81.207.2554,094
30241.81.208.0/20241.81.208.1 to 241.81.223.254241.81.223.2554,094
31241.81.224.0/20241.81.224.1 to 241.81.239.254241.81.239.2554,094
32241.81.240.0/20241.81.240.1 to 241.81.255.254241.81.255.2554,094
33241.82.0.0/20241.82.0.1 to 241.82.15.254241.82.15.2554,094
34241.82.16.0/20241.82.16.1 to 241.82.31.254241.82.31.2554,094
35241.82.32.0/20241.82.32.1 to 241.82.47.254241.82.47.2554,094
36241.82.48.0/20241.82.48.1 to 241.82.63.254241.82.63.2554,094
37241.82.64.0/20241.82.64.1 to 241.82.79.254241.82.79.2554,094
38241.82.80.0/20241.82.80.1 to 241.82.95.254241.82.95.2554,094
39241.82.96.0/20241.82.96.1 to 241.82.111.254241.82.111.2554,094
40241.82.112.0/20241.82.112.1 to 241.82.127.254241.82.127.2554,094
41241.82.128.0/20241.82.128.1 to 241.82.143.254241.82.143.2554,094
42241.82.144.0/20241.82.144.1 to 241.82.159.254241.82.159.2554,094
43241.82.160.0/20241.82.160.1 to 241.82.175.254241.82.175.2554,094
44241.82.176.0/20241.82.176.1 to 241.82.191.254241.82.191.2554,094
45241.82.192.0/20241.82.192.1 to 241.82.207.254241.82.207.2554,094
46241.82.208.0/20241.82.208.1 to 241.82.223.254241.82.223.2554,094
47241.82.224.0/20241.82.224.1 to 241.82.239.254241.82.239.2554,094
48241.82.240.0/20241.82.240.1 to 241.82.255.254241.82.255.2554,094
49241.83.0.0/20241.83.0.1 to 241.83.15.254241.83.15.2554,094
50241.83.16.0/20241.83.16.1 to 241.83.31.254241.83.31.2554,094
51241.83.32.0/20241.83.32.1 to 241.83.47.254241.83.47.2554,094
52241.83.48.0/20241.83.48.1 to 241.83.63.254241.83.63.2554,094
53241.83.64.0/20241.83.64.1 to 241.83.79.254241.83.79.2554,094
54241.83.80.0/20241.83.80.1 to 241.83.95.254241.83.95.2554,094
55241.83.96.0/20241.83.96.1 to 241.83.111.254241.83.111.2554,094
56241.83.112.0/20241.83.112.1 to 241.83.127.254241.83.127.2554,094
57241.83.128.0/20241.83.128.1 to 241.83.143.254241.83.143.2554,094
58241.83.144.0/20241.83.144.1 to 241.83.159.254241.83.159.2554,094
59241.83.160.0/20241.83.160.1 to 241.83.175.254241.83.175.2554,094
60241.83.176.0/20241.83.176.1 to 241.83.191.254241.83.191.2554,094
61241.83.192.0/20241.83.192.1 to 241.83.207.254241.83.207.2554,094
62241.83.208.0/20241.83.208.1 to 241.83.223.254241.83.223.2554,094
63241.83.224.0/20241.83.224.1 to 241.83.239.254241.83.239.2554,094
64241.83.240.0/20241.83.240.1 to 241.83.255.254241.83.255.2554,094
65241.84.0.0/20241.84.0.1 to 241.84.15.254241.84.15.2554,094
66241.84.16.0/20241.84.16.1 to 241.84.31.254241.84.31.2554,094
67241.84.32.0/20241.84.32.1 to 241.84.47.254241.84.47.2554,094
68241.84.48.0/20241.84.48.1 to 241.84.63.254241.84.63.2554,094
69241.84.64.0/20241.84.64.1 to 241.84.79.254241.84.79.2554,094
70241.84.80.0/20241.84.80.1 to 241.84.95.254241.84.95.2554,094
71241.84.96.0/20241.84.96.1 to 241.84.111.254241.84.111.2554,094
72241.84.112.0/20241.84.112.1 to 241.84.127.254241.84.127.2554,094
73241.84.128.0/20241.84.128.1 to 241.84.143.254241.84.143.2554,094
74241.84.144.0/20241.84.144.1 to 241.84.159.254241.84.159.2554,094
75241.84.160.0/20241.84.160.1 to 241.84.175.254241.84.175.2554,094
76241.84.176.0/20241.84.176.1 to 241.84.191.254241.84.191.2554,094
77241.84.192.0/20241.84.192.1 to 241.84.207.254241.84.207.2554,094
78241.84.208.0/20241.84.208.1 to 241.84.223.254241.84.223.2554,094
79241.84.224.0/20241.84.224.1 to 241.84.239.254241.84.239.2554,094
80241.84.240.0/20241.84.240.1 to 241.84.255.254241.84.255.2554,094
81241.85.0.0/20241.85.0.1 to 241.85.15.254241.85.15.2554,094
82241.85.16.0/20241.85.16.1 to 241.85.31.254241.85.31.2554,094
83241.85.32.0/20241.85.32.1 to 241.85.47.254241.85.47.2554,094
84241.85.48.0/20241.85.48.1 to 241.85.63.254241.85.63.2554,094
85241.85.64.0/20241.85.64.1 to 241.85.79.254241.85.79.2554,094
86241.85.80.0/20241.85.80.1 to 241.85.95.254241.85.95.2554,094
87241.85.96.0/20241.85.96.1 to 241.85.111.254241.85.111.2554,094
88241.85.112.0/20241.85.112.1 to 241.85.127.254241.85.127.2554,094
89241.85.128.0/20241.85.128.1 to 241.85.143.254241.85.143.2554,094
90241.85.144.0/20241.85.144.1 to 241.85.159.254241.85.159.2554,094
91241.85.160.0/20241.85.160.1 to 241.85.175.254241.85.175.2554,094
92241.85.176.0/20241.85.176.1 to 241.85.191.254241.85.191.2554,094
93241.85.192.0/20241.85.192.1 to 241.85.207.254241.85.207.2554,094
94241.85.208.0/20241.85.208.1 to 241.85.223.254241.85.223.2554,094
95241.85.224.0/20241.85.224.1 to 241.85.239.254241.85.239.2554,094
96241.85.240.0/20241.85.240.1 to 241.85.255.254241.85.255.2554,094
97241.86.0.0/20241.86.0.1 to 241.86.15.254241.86.15.2554,094
98241.86.16.0/20241.86.16.1 to 241.86.31.254241.86.31.2554,094
99241.86.32.0/20241.86.32.1 to 241.86.47.254241.86.47.2554,094
100241.86.48.0/20241.86.48.1 to 241.86.63.254241.86.63.2554,094
101241.86.64.0/20241.86.64.1 to 241.86.79.254241.86.79.2554,094
102241.86.80.0/20241.86.80.1 to 241.86.95.254241.86.95.2554,094
103241.86.96.0/20241.86.96.1 to 241.86.111.254241.86.111.2554,094
104241.86.112.0/20241.86.112.1 to 241.86.127.254241.86.127.2554,094
105241.86.128.0/20241.86.128.1 to 241.86.143.254241.86.143.2554,094
106241.86.144.0/20241.86.144.1 to 241.86.159.254241.86.159.2554,094
107241.86.160.0/20241.86.160.1 to 241.86.175.254241.86.175.2554,094
108241.86.176.0/20241.86.176.1 to 241.86.191.254241.86.191.2554,094
109241.86.192.0/20241.86.192.1 to 241.86.207.254241.86.207.2554,094
110241.86.208.0/20241.86.208.1 to 241.86.223.254241.86.223.2554,094
111241.86.224.0/20241.86.224.1 to 241.86.239.254241.86.239.2554,094
112241.86.240.0/20241.86.240.1 to 241.86.255.254241.86.255.2554,094
113241.87.0.0/20241.87.0.1 to 241.87.15.254241.87.15.2554,094
114241.87.16.0/20241.87.16.1 to 241.87.31.254241.87.31.2554,094
115241.87.32.0/20241.87.32.1 to 241.87.47.254241.87.47.2554,094
116241.87.48.0/20241.87.48.1 to 241.87.63.254241.87.63.2554,094
117241.87.64.0/20241.87.64.1 to 241.87.79.254241.87.79.2554,094
118241.87.80.0/20241.87.80.1 to 241.87.95.254241.87.95.2554,094
119241.87.96.0/20241.87.96.1 to 241.87.111.254241.87.111.2554,094
120241.87.112.0/20241.87.112.1 to 241.87.127.254241.87.127.2554,094
121241.87.128.0/20241.87.128.1 to 241.87.143.254241.87.143.2554,094
122241.87.144.0/20241.87.144.1 to 241.87.159.254241.87.159.2554,094
123241.87.160.0/20241.87.160.1 to 241.87.175.254241.87.175.2554,094
124241.87.176.0/20241.87.176.1 to 241.87.191.254241.87.191.2554,094
125241.87.192.0/20241.87.192.1 to 241.87.207.254241.87.207.2554,094
126241.87.208.0/20241.87.208.1 to 241.87.223.254241.87.223.2554,094
127241.87.224.0/20241.87.224.1 to 241.87.239.254241.87.239.2554,094
128241.87.240.0/20241.87.240.1 to 241.87.255.254241.87.255.2554,094
129241.88.0.0/20241.88.0.1 to 241.88.15.254241.88.15.2554,094
130241.88.16.0/20241.88.16.1 to 241.88.31.254241.88.31.2554,094
131241.88.32.0/20241.88.32.1 to 241.88.47.254241.88.47.2554,094
132241.88.48.0/20241.88.48.1 to 241.88.63.254241.88.63.2554,094
133241.88.64.0/20241.88.64.1 to 241.88.79.254241.88.79.2554,094
134241.88.80.0/20241.88.80.1 to 241.88.95.254241.88.95.2554,094
135241.88.96.0/20241.88.96.1 to 241.88.111.254241.88.111.2554,094
136241.88.112.0/20241.88.112.1 to 241.88.127.254241.88.127.2554,094
137241.88.128.0/20241.88.128.1 to 241.88.143.254241.88.143.2554,094
138241.88.144.0/20241.88.144.1 to 241.88.159.254241.88.159.2554,094
139241.88.160.0/20241.88.160.1 to 241.88.175.254241.88.175.2554,094
140241.88.176.0/20241.88.176.1 to 241.88.191.254241.88.191.2554,094
141241.88.192.0/20241.88.192.1 to 241.88.207.254241.88.207.2554,094
142241.88.208.0/20241.88.208.1 to 241.88.223.254241.88.223.2554,094
143241.88.224.0/20241.88.224.1 to 241.88.239.254241.88.239.2554,094
144241.88.240.0/20241.88.240.1 to 241.88.255.254241.88.255.2554,094
145241.89.0.0/20241.89.0.1 to 241.89.15.254241.89.15.2554,094
146241.89.16.0/20241.89.16.1 to 241.89.31.254241.89.31.2554,094
147241.89.32.0/20241.89.32.1 to 241.89.47.254241.89.47.2554,094
148241.89.48.0/20241.89.48.1 to 241.89.63.254241.89.63.2554,094
149241.89.64.0/20241.89.64.1 to 241.89.79.254241.89.79.2554,094
150241.89.80.0/20241.89.80.1 to 241.89.95.254241.89.95.2554,094
151241.89.96.0/20241.89.96.1 to 241.89.111.254241.89.111.2554,094
152241.89.112.0/20241.89.112.1 to 241.89.127.254241.89.127.2554,094
153241.89.128.0/20241.89.128.1 to 241.89.143.254241.89.143.2554,094
154241.89.144.0/20241.89.144.1 to 241.89.159.254241.89.159.2554,094
155241.89.160.0/20241.89.160.1 to 241.89.175.254241.89.175.2554,094
156241.89.176.0/20241.89.176.1 to 241.89.191.254241.89.191.2554,094
157241.89.192.0/20241.89.192.1 to 241.89.207.254241.89.207.2554,094
158241.89.208.0/20241.89.208.1 to 241.89.223.254241.89.223.2554,094
159241.89.224.0/20241.89.224.1 to 241.89.239.254241.89.239.2554,094
160241.89.240.0/20241.89.240.1 to 241.89.255.254241.89.255.2554,094
161241.90.0.0/20241.90.0.1 to 241.90.15.254241.90.15.2554,094
162241.90.16.0/20241.90.16.1 to 241.90.31.254241.90.31.2554,094
163241.90.32.0/20241.90.32.1 to 241.90.47.254241.90.47.2554,094
164241.90.48.0/20241.90.48.1 to 241.90.63.254241.90.63.2554,094
165241.90.64.0/20241.90.64.1 to 241.90.79.254241.90.79.2554,094
166241.90.80.0/20241.90.80.1 to 241.90.95.254241.90.95.2554,094
167241.90.96.0/20241.90.96.1 to 241.90.111.254241.90.111.2554,094
168241.90.112.0/20241.90.112.1 to 241.90.127.254241.90.127.2554,094
169241.90.128.0/20241.90.128.1 to 241.90.143.254241.90.143.2554,094
170241.90.144.0/20241.90.144.1 to 241.90.159.254241.90.159.2554,094
171241.90.160.0/20241.90.160.1 to 241.90.175.254241.90.175.2554,094
172241.90.176.0/20241.90.176.1 to 241.90.191.254241.90.191.2554,094
173241.90.192.0/20241.90.192.1 to 241.90.207.254241.90.207.2554,094
174241.90.208.0/20241.90.208.1 to 241.90.223.254241.90.223.2554,094
175241.90.224.0/20241.90.224.1 to 241.90.239.254241.90.239.2554,094
176241.90.240.0/20241.90.240.1 to 241.90.255.254241.90.255.2554,094
177241.91.0.0/20241.91.0.1 to 241.91.15.254241.91.15.2554,094
178241.91.16.0/20241.91.16.1 to 241.91.31.254241.91.31.2554,094
179241.91.32.0/20241.91.32.1 to 241.91.47.254241.91.47.2554,094
180241.91.48.0/20241.91.48.1 to 241.91.63.254241.91.63.2554,094
181241.91.64.0/20241.91.64.1 to 241.91.79.254241.91.79.2554,094
182241.91.80.0/20241.91.80.1 to 241.91.95.254241.91.95.2554,094
183241.91.96.0/20241.91.96.1 to 241.91.111.254241.91.111.2554,094
184241.91.112.0/20241.91.112.1 to 241.91.127.254241.91.127.2554,094
185241.91.128.0/20241.91.128.1 to 241.91.143.254241.91.143.2554,094
186241.91.144.0/20241.91.144.1 to 241.91.159.254241.91.159.2554,094
187241.91.160.0/20241.91.160.1 to 241.91.175.254241.91.175.2554,094
188241.91.176.0/20241.91.176.1 to 241.91.191.254241.91.191.2554,094
189241.91.192.0/20241.91.192.1 to 241.91.207.254241.91.207.2554,094
190241.91.208.0/20241.91.208.1 to 241.91.223.254241.91.223.2554,094
191241.91.224.0/20241.91.224.1 to 241.91.239.254241.91.239.2554,094
192241.91.240.0/20241.91.240.1 to 241.91.255.254241.91.255.2554,094
193241.92.0.0/20241.92.0.1 to 241.92.15.254241.92.15.2554,094
194241.92.16.0/20241.92.16.1 to 241.92.31.254241.92.31.2554,094
195241.92.32.0/20241.92.32.1 to 241.92.47.254241.92.47.2554,094
196241.92.48.0/20241.92.48.1 to 241.92.63.254241.92.63.2554,094
197241.92.64.0/20241.92.64.1 to 241.92.79.254241.92.79.2554,094
198241.92.80.0/20241.92.80.1 to 241.92.95.254241.92.95.2554,094
199241.92.96.0/20241.92.96.1 to 241.92.111.254241.92.111.2554,094
200241.92.112.0/20241.92.112.1 to 241.92.127.254241.92.127.2554,094
201241.92.128.0/20241.92.128.1 to 241.92.143.254241.92.143.2554,094
202241.92.144.0/20241.92.144.1 to 241.92.159.254241.92.159.2554,094
203241.92.160.0/20241.92.160.1 to 241.92.175.254241.92.175.2554,094
204241.92.176.0/20241.92.176.1 to 241.92.191.254241.92.191.2554,094
205241.92.192.0/20241.92.192.1 to 241.92.207.254241.92.207.2554,094
206241.92.208.0/20241.92.208.1 to 241.92.223.254241.92.223.2554,094
207241.92.224.0/20241.92.224.1 to 241.92.239.254241.92.239.2554,094
208241.92.240.0/20241.92.240.1 to 241.92.255.254241.92.255.2554,094
209241.93.0.0/20241.93.0.1 to 241.93.15.254241.93.15.2554,094
210241.93.16.0/20241.93.16.1 to 241.93.31.254241.93.31.2554,094
211241.93.32.0/20241.93.32.1 to 241.93.47.254241.93.47.2554,094
212241.93.48.0/20241.93.48.1 to 241.93.63.254241.93.63.2554,094
213241.93.64.0/20241.93.64.1 to 241.93.79.254241.93.79.2554,094
214241.93.80.0/20241.93.80.1 to 241.93.95.254241.93.95.2554,094
215241.93.96.0/20241.93.96.1 to 241.93.111.254241.93.111.2554,094
216241.93.112.0/20241.93.112.1 to 241.93.127.254241.93.127.2554,094
217241.93.128.0/20241.93.128.1 to 241.93.143.254241.93.143.2554,094
218241.93.144.0/20241.93.144.1 to 241.93.159.254241.93.159.2554,094
219241.93.160.0/20241.93.160.1 to 241.93.175.254241.93.175.2554,094
220241.93.176.0/20241.93.176.1 to 241.93.191.254241.93.191.2554,094
221241.93.192.0/20241.93.192.1 to 241.93.207.254241.93.207.2554,094
222241.93.208.0/20241.93.208.1 to 241.93.223.254241.93.223.2554,094
223241.93.224.0/20241.93.224.1 to 241.93.239.254241.93.239.2554,094
224241.93.240.0/20241.93.240.1 to 241.93.255.254241.93.255.2554,094
225241.94.0.0/20241.94.0.1 to 241.94.15.254241.94.15.2554,094
226241.94.16.0/20241.94.16.1 to 241.94.31.254241.94.31.2554,094
227241.94.32.0/20241.94.32.1 to 241.94.47.254241.94.47.2554,094
228241.94.48.0/20241.94.48.1 to 241.94.63.254241.94.63.2554,094
229241.94.64.0/20241.94.64.1 to 241.94.79.254241.94.79.2554,094
230241.94.80.0/20241.94.80.1 to 241.94.95.254241.94.95.2554,094
231241.94.96.0/20241.94.96.1 to 241.94.111.254241.94.111.2554,094
232241.94.112.0/20241.94.112.1 to 241.94.127.254241.94.127.2554,094
233241.94.128.0/20241.94.128.1 to 241.94.143.254241.94.143.2554,094
234241.94.144.0/20241.94.144.1 to 241.94.159.254241.94.159.2554,094
235241.94.160.0/20241.94.160.1 to 241.94.175.254241.94.175.2554,094
236241.94.176.0/20241.94.176.1 to 241.94.191.254241.94.191.2554,094
237241.94.192.0/20241.94.192.1 to 241.94.207.254241.94.207.2554,094
238241.94.208.0/20241.94.208.1 to 241.94.223.254241.94.223.2554,094
239241.94.224.0/20241.94.224.1 to 241.94.239.254241.94.239.2554,094
240241.94.240.0/20241.94.240.1 to 241.94.255.254241.94.255.2554,094
241241.95.0.0/20241.95.0.1 to 241.95.15.254241.95.15.2554,094
242241.95.16.0/20241.95.16.1 to 241.95.31.254241.95.31.2554,094
243241.95.32.0/20241.95.32.1 to 241.95.47.254241.95.47.2554,094
244241.95.48.0/20241.95.48.1 to 241.95.63.254241.95.63.2554,094
245241.95.64.0/20241.95.64.1 to 241.95.79.254241.95.79.2554,094
246241.95.80.0/20241.95.80.1 to 241.95.95.254241.95.95.2554,094
247241.95.96.0/20241.95.96.1 to 241.95.111.254241.95.111.2554,094
248241.95.112.0/20241.95.112.1 to 241.95.127.254241.95.127.2554,094
249241.95.128.0/20241.95.128.1 to 241.95.143.254241.95.143.2554,094
250241.95.144.0/20241.95.144.1 to 241.95.159.254241.95.159.2554,094
251241.95.160.0/20241.95.160.1 to 241.95.175.254241.95.175.2554,094
252241.95.176.0/20241.95.176.1 to 241.95.191.254241.95.191.2554,094
253241.95.192.0/20241.95.192.1 to 241.95.207.254241.95.207.2554,094
254241.95.208.0/20241.95.208.1 to 241.95.223.254241.95.223.2554,094
255241.95.224.0/20241.95.224.1 to 241.95.239.254241.95.239.2554,094
256241.95.240.0/20241.95.240.1 to 241.95.255.254241.95.255.2554,094

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.