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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.

Network232.2.0.0/17
Usable hosts32,766
Subnet mask255.255.128.0
Addresses32,768
Network address
232.2.0.0
Broadcast address
232.2.127.255
First usable
232.2.0.1
Last usable
232.2.127.254
Usable hosts
32,766 (32,768 less the network and broadcast addresses)
Subnet mask
255.255.128.0
Wildcard mask
0.0.127.255 (Cisco ACLs, OSPF)
Prefix length
/17
Type
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex E8020000 · Integer 3892445184 to 3892477951
Reverse DNS zones
0.2.232.in-addr.arpa
1.2.232.in-addr.arpa
2.2.232.in-addr.arpa
3.2.232.in-addr.arpa
4.2.232.in-addr.arpa
5.2.232.in-addr.arpa
6.2.232.in-addr.arpa
7.2.232.in-addr.arpa
8.2.232.in-addr.arpa
9.2.232.in-addr.arpa
10.2.232.in-addr.arpa
11.2.232.in-addr.arpa
12.2.232.in-addr.arpa
13.2.232.in-addr.arpa
14.2.232.in-addr.arpa
15.2.232.in-addr.arpa
and 112 more
/17 is not on a 8-bit boundary, so it takes 128 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11101000.00000010.00000000.00000000232.2.0.0
Subnet mask11111111.11111111.10000000.00000000255.255.128.0
Network11101000.00000010.00000000.00000000232.2.0.0
Broadcast11101000.00000010.01111111.11111111232.2.127.255
Split into smaller subnets/26
/18 (2)/19 (4)/20 (8)/21 (16)/22 (32)/23 (64)/24 (128)/25 (256)/26 (512)/27 (1,024)/28 (2,048)/29 (4,096)

232.2.0.0/17 makes 512 subnets of /26; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1232.2.0.0/26232.2.0.1 to 232.2.0.62232.2.0.6362
2232.2.0.64/26232.2.0.65 to 232.2.0.126232.2.0.12762
3232.2.0.128/26232.2.0.129 to 232.2.0.190232.2.0.19162
4232.2.0.192/26232.2.0.193 to 232.2.0.254232.2.0.25562
5232.2.1.0/26232.2.1.1 to 232.2.1.62232.2.1.6362
6232.2.1.64/26232.2.1.65 to 232.2.1.126232.2.1.12762
7232.2.1.128/26232.2.1.129 to 232.2.1.190232.2.1.19162
8232.2.1.192/26232.2.1.193 to 232.2.1.254232.2.1.25562
9232.2.2.0/26232.2.2.1 to 232.2.2.62232.2.2.6362
10232.2.2.64/26232.2.2.65 to 232.2.2.126232.2.2.12762
11232.2.2.128/26232.2.2.129 to 232.2.2.190232.2.2.19162
12232.2.2.192/26232.2.2.193 to 232.2.2.254232.2.2.25562
13232.2.3.0/26232.2.3.1 to 232.2.3.62232.2.3.6362
14232.2.3.64/26232.2.3.65 to 232.2.3.126232.2.3.12762
15232.2.3.128/26232.2.3.129 to 232.2.3.190232.2.3.19162
16232.2.3.192/26232.2.3.193 to 232.2.3.254232.2.3.25562
17232.2.4.0/26232.2.4.1 to 232.2.4.62232.2.4.6362
18232.2.4.64/26232.2.4.65 to 232.2.4.126232.2.4.12762
19232.2.4.128/26232.2.4.129 to 232.2.4.190232.2.4.19162
20232.2.4.192/26232.2.4.193 to 232.2.4.254232.2.4.25562
21232.2.5.0/26232.2.5.1 to 232.2.5.62232.2.5.6362
22232.2.5.64/26232.2.5.65 to 232.2.5.126232.2.5.12762
23232.2.5.128/26232.2.5.129 to 232.2.5.190232.2.5.19162
24232.2.5.192/26232.2.5.193 to 232.2.5.254232.2.5.25562
25232.2.6.0/26232.2.6.1 to 232.2.6.62232.2.6.6362
26232.2.6.64/26232.2.6.65 to 232.2.6.126232.2.6.12762
27232.2.6.128/26232.2.6.129 to 232.2.6.190232.2.6.19162
28232.2.6.192/26232.2.6.193 to 232.2.6.254232.2.6.25562
29232.2.7.0/26232.2.7.1 to 232.2.7.62232.2.7.6362
30232.2.7.64/26232.2.7.65 to 232.2.7.126232.2.7.12762
31232.2.7.128/26232.2.7.129 to 232.2.7.190232.2.7.19162
32232.2.7.192/26232.2.7.193 to 232.2.7.254232.2.7.25562
33232.2.8.0/26232.2.8.1 to 232.2.8.62232.2.8.6362
34232.2.8.64/26232.2.8.65 to 232.2.8.126232.2.8.12762
35232.2.8.128/26232.2.8.129 to 232.2.8.190232.2.8.19162
36232.2.8.192/26232.2.8.193 to 232.2.8.254232.2.8.25562
37232.2.9.0/26232.2.9.1 to 232.2.9.62232.2.9.6362
38232.2.9.64/26232.2.9.65 to 232.2.9.126232.2.9.12762
39232.2.9.128/26232.2.9.129 to 232.2.9.190232.2.9.19162
40232.2.9.192/26232.2.9.193 to 232.2.9.254232.2.9.25562
41232.2.10.0/26232.2.10.1 to 232.2.10.62232.2.10.6362
42232.2.10.64/26232.2.10.65 to 232.2.10.126232.2.10.12762
43232.2.10.128/26232.2.10.129 to 232.2.10.190232.2.10.19162
44232.2.10.192/26232.2.10.193 to 232.2.10.254232.2.10.25562
45232.2.11.0/26232.2.11.1 to 232.2.11.62232.2.11.6362
46232.2.11.64/26232.2.11.65 to 232.2.11.126232.2.11.12762
47232.2.11.128/26232.2.11.129 to 232.2.11.190232.2.11.19162
48232.2.11.192/26232.2.11.193 to 232.2.11.254232.2.11.25562
49232.2.12.0/26232.2.12.1 to 232.2.12.62232.2.12.6362
50232.2.12.64/26232.2.12.65 to 232.2.12.126232.2.12.12762
51232.2.12.128/26232.2.12.129 to 232.2.12.190232.2.12.19162
52232.2.12.192/26232.2.12.193 to 232.2.12.254232.2.12.25562
53232.2.13.0/26232.2.13.1 to 232.2.13.62232.2.13.6362
54232.2.13.64/26232.2.13.65 to 232.2.13.126232.2.13.12762
55232.2.13.128/26232.2.13.129 to 232.2.13.190232.2.13.19162
56232.2.13.192/26232.2.13.193 to 232.2.13.254232.2.13.25562
57232.2.14.0/26232.2.14.1 to 232.2.14.62232.2.14.6362
58232.2.14.64/26232.2.14.65 to 232.2.14.126232.2.14.12762
59232.2.14.128/26232.2.14.129 to 232.2.14.190232.2.14.19162
60232.2.14.192/26232.2.14.193 to 232.2.14.254232.2.14.25562
61232.2.15.0/26232.2.15.1 to 232.2.15.62232.2.15.6362
62232.2.15.64/26232.2.15.65 to 232.2.15.126232.2.15.12762
63232.2.15.128/26232.2.15.129 to 232.2.15.190232.2.15.19162
64232.2.15.192/26232.2.15.193 to 232.2.15.254232.2.15.25562
65232.2.16.0/26232.2.16.1 to 232.2.16.62232.2.16.6362
66232.2.16.64/26232.2.16.65 to 232.2.16.126232.2.16.12762
67232.2.16.128/26232.2.16.129 to 232.2.16.190232.2.16.19162
68232.2.16.192/26232.2.16.193 to 232.2.16.254232.2.16.25562
69232.2.17.0/26232.2.17.1 to 232.2.17.62232.2.17.6362
70232.2.17.64/26232.2.17.65 to 232.2.17.126232.2.17.12762
71232.2.17.128/26232.2.17.129 to 232.2.17.190232.2.17.19162
72232.2.17.192/26232.2.17.193 to 232.2.17.254232.2.17.25562
73232.2.18.0/26232.2.18.1 to 232.2.18.62232.2.18.6362
74232.2.18.64/26232.2.18.65 to 232.2.18.126232.2.18.12762
75232.2.18.128/26232.2.18.129 to 232.2.18.190232.2.18.19162
76232.2.18.192/26232.2.18.193 to 232.2.18.254232.2.18.25562
77232.2.19.0/26232.2.19.1 to 232.2.19.62232.2.19.6362
78232.2.19.64/26232.2.19.65 to 232.2.19.126232.2.19.12762
79232.2.19.128/26232.2.19.129 to 232.2.19.190232.2.19.19162
80232.2.19.192/26232.2.19.193 to 232.2.19.254232.2.19.25562
81232.2.20.0/26232.2.20.1 to 232.2.20.62232.2.20.6362
82232.2.20.64/26232.2.20.65 to 232.2.20.126232.2.20.12762
83232.2.20.128/26232.2.20.129 to 232.2.20.190232.2.20.19162
84232.2.20.192/26232.2.20.193 to 232.2.20.254232.2.20.25562
85232.2.21.0/26232.2.21.1 to 232.2.21.62232.2.21.6362
86232.2.21.64/26232.2.21.65 to 232.2.21.126232.2.21.12762
87232.2.21.128/26232.2.21.129 to 232.2.21.190232.2.21.19162
88232.2.21.192/26232.2.21.193 to 232.2.21.254232.2.21.25562
89232.2.22.0/26232.2.22.1 to 232.2.22.62232.2.22.6362
90232.2.22.64/26232.2.22.65 to 232.2.22.126232.2.22.12762
91232.2.22.128/26232.2.22.129 to 232.2.22.190232.2.22.19162
92232.2.22.192/26232.2.22.193 to 232.2.22.254232.2.22.25562
93232.2.23.0/26232.2.23.1 to 232.2.23.62232.2.23.6362
94232.2.23.64/26232.2.23.65 to 232.2.23.126232.2.23.12762
95232.2.23.128/26232.2.23.129 to 232.2.23.190232.2.23.19162
96232.2.23.192/26232.2.23.193 to 232.2.23.254232.2.23.25562
97232.2.24.0/26232.2.24.1 to 232.2.24.62232.2.24.6362
98232.2.24.64/26232.2.24.65 to 232.2.24.126232.2.24.12762
99232.2.24.128/26232.2.24.129 to 232.2.24.190232.2.24.19162
100232.2.24.192/26232.2.24.193 to 232.2.24.254232.2.24.25562
101232.2.25.0/26232.2.25.1 to 232.2.25.62232.2.25.6362
102232.2.25.64/26232.2.25.65 to 232.2.25.126232.2.25.12762
103232.2.25.128/26232.2.25.129 to 232.2.25.190232.2.25.19162
104232.2.25.192/26232.2.25.193 to 232.2.25.254232.2.25.25562
105232.2.26.0/26232.2.26.1 to 232.2.26.62232.2.26.6362
106232.2.26.64/26232.2.26.65 to 232.2.26.126232.2.26.12762
107232.2.26.128/26232.2.26.129 to 232.2.26.190232.2.26.19162
108232.2.26.192/26232.2.26.193 to 232.2.26.254232.2.26.25562
109232.2.27.0/26232.2.27.1 to 232.2.27.62232.2.27.6362
110232.2.27.64/26232.2.27.65 to 232.2.27.126232.2.27.12762
111232.2.27.128/26232.2.27.129 to 232.2.27.190232.2.27.19162
112232.2.27.192/26232.2.27.193 to 232.2.27.254232.2.27.25562
113232.2.28.0/26232.2.28.1 to 232.2.28.62232.2.28.6362
114232.2.28.64/26232.2.28.65 to 232.2.28.126232.2.28.12762
115232.2.28.128/26232.2.28.129 to 232.2.28.190232.2.28.19162
116232.2.28.192/26232.2.28.193 to 232.2.28.254232.2.28.25562
117232.2.29.0/26232.2.29.1 to 232.2.29.62232.2.29.6362
118232.2.29.64/26232.2.29.65 to 232.2.29.126232.2.29.12762
119232.2.29.128/26232.2.29.129 to 232.2.29.190232.2.29.19162
120232.2.29.192/26232.2.29.193 to 232.2.29.254232.2.29.25562
121232.2.30.0/26232.2.30.1 to 232.2.30.62232.2.30.6362
122232.2.30.64/26232.2.30.65 to 232.2.30.126232.2.30.12762
123232.2.30.128/26232.2.30.129 to 232.2.30.190232.2.30.19162
124232.2.30.192/26232.2.30.193 to 232.2.30.254232.2.30.25562
125232.2.31.0/26232.2.31.1 to 232.2.31.62232.2.31.6362
126232.2.31.64/26232.2.31.65 to 232.2.31.126232.2.31.12762
127232.2.31.128/26232.2.31.129 to 232.2.31.190232.2.31.19162
128232.2.31.192/26232.2.31.193 to 232.2.31.254232.2.31.25562
129232.2.32.0/26232.2.32.1 to 232.2.32.62232.2.32.6362
130232.2.32.64/26232.2.32.65 to 232.2.32.126232.2.32.12762
131232.2.32.128/26232.2.32.129 to 232.2.32.190232.2.32.19162
132232.2.32.192/26232.2.32.193 to 232.2.32.254232.2.32.25562
133232.2.33.0/26232.2.33.1 to 232.2.33.62232.2.33.6362
134232.2.33.64/26232.2.33.65 to 232.2.33.126232.2.33.12762
135232.2.33.128/26232.2.33.129 to 232.2.33.190232.2.33.19162
136232.2.33.192/26232.2.33.193 to 232.2.33.254232.2.33.25562
137232.2.34.0/26232.2.34.1 to 232.2.34.62232.2.34.6362
138232.2.34.64/26232.2.34.65 to 232.2.34.126232.2.34.12762
139232.2.34.128/26232.2.34.129 to 232.2.34.190232.2.34.19162
140232.2.34.192/26232.2.34.193 to 232.2.34.254232.2.34.25562
141232.2.35.0/26232.2.35.1 to 232.2.35.62232.2.35.6362
142232.2.35.64/26232.2.35.65 to 232.2.35.126232.2.35.12762
143232.2.35.128/26232.2.35.129 to 232.2.35.190232.2.35.19162
144232.2.35.192/26232.2.35.193 to 232.2.35.254232.2.35.25562
145232.2.36.0/26232.2.36.1 to 232.2.36.62232.2.36.6362
146232.2.36.64/26232.2.36.65 to 232.2.36.126232.2.36.12762
147232.2.36.128/26232.2.36.129 to 232.2.36.190232.2.36.19162
148232.2.36.192/26232.2.36.193 to 232.2.36.254232.2.36.25562
149232.2.37.0/26232.2.37.1 to 232.2.37.62232.2.37.6362
150232.2.37.64/26232.2.37.65 to 232.2.37.126232.2.37.12762
151232.2.37.128/26232.2.37.129 to 232.2.37.190232.2.37.19162
152232.2.37.192/26232.2.37.193 to 232.2.37.254232.2.37.25562
153232.2.38.0/26232.2.38.1 to 232.2.38.62232.2.38.6362
154232.2.38.64/26232.2.38.65 to 232.2.38.126232.2.38.12762
155232.2.38.128/26232.2.38.129 to 232.2.38.190232.2.38.19162
156232.2.38.192/26232.2.38.193 to 232.2.38.254232.2.38.25562
157232.2.39.0/26232.2.39.1 to 232.2.39.62232.2.39.6362
158232.2.39.64/26232.2.39.65 to 232.2.39.126232.2.39.12762
159232.2.39.128/26232.2.39.129 to 232.2.39.190232.2.39.19162
160232.2.39.192/26232.2.39.193 to 232.2.39.254232.2.39.25562
161232.2.40.0/26232.2.40.1 to 232.2.40.62232.2.40.6362
162232.2.40.64/26232.2.40.65 to 232.2.40.126232.2.40.12762
163232.2.40.128/26232.2.40.129 to 232.2.40.190232.2.40.19162
164232.2.40.192/26232.2.40.193 to 232.2.40.254232.2.40.25562
165232.2.41.0/26232.2.41.1 to 232.2.41.62232.2.41.6362
166232.2.41.64/26232.2.41.65 to 232.2.41.126232.2.41.12762
167232.2.41.128/26232.2.41.129 to 232.2.41.190232.2.41.19162
168232.2.41.192/26232.2.41.193 to 232.2.41.254232.2.41.25562
169232.2.42.0/26232.2.42.1 to 232.2.42.62232.2.42.6362
170232.2.42.64/26232.2.42.65 to 232.2.42.126232.2.42.12762
171232.2.42.128/26232.2.42.129 to 232.2.42.190232.2.42.19162
172232.2.42.192/26232.2.42.193 to 232.2.42.254232.2.42.25562
173232.2.43.0/26232.2.43.1 to 232.2.43.62232.2.43.6362
174232.2.43.64/26232.2.43.65 to 232.2.43.126232.2.43.12762
175232.2.43.128/26232.2.43.129 to 232.2.43.190232.2.43.19162
176232.2.43.192/26232.2.43.193 to 232.2.43.254232.2.43.25562
177232.2.44.0/26232.2.44.1 to 232.2.44.62232.2.44.6362
178232.2.44.64/26232.2.44.65 to 232.2.44.126232.2.44.12762
179232.2.44.128/26232.2.44.129 to 232.2.44.190232.2.44.19162
180232.2.44.192/26232.2.44.193 to 232.2.44.254232.2.44.25562
181232.2.45.0/26232.2.45.1 to 232.2.45.62232.2.45.6362
182232.2.45.64/26232.2.45.65 to 232.2.45.126232.2.45.12762
183232.2.45.128/26232.2.45.129 to 232.2.45.190232.2.45.19162
184232.2.45.192/26232.2.45.193 to 232.2.45.254232.2.45.25562
185232.2.46.0/26232.2.46.1 to 232.2.46.62232.2.46.6362
186232.2.46.64/26232.2.46.65 to 232.2.46.126232.2.46.12762
187232.2.46.128/26232.2.46.129 to 232.2.46.190232.2.46.19162
188232.2.46.192/26232.2.46.193 to 232.2.46.254232.2.46.25562
189232.2.47.0/26232.2.47.1 to 232.2.47.62232.2.47.6362
190232.2.47.64/26232.2.47.65 to 232.2.47.126232.2.47.12762
191232.2.47.128/26232.2.47.129 to 232.2.47.190232.2.47.19162
192232.2.47.192/26232.2.47.193 to 232.2.47.254232.2.47.25562
193232.2.48.0/26232.2.48.1 to 232.2.48.62232.2.48.6362
194232.2.48.64/26232.2.48.65 to 232.2.48.126232.2.48.12762
195232.2.48.128/26232.2.48.129 to 232.2.48.190232.2.48.19162
196232.2.48.192/26232.2.48.193 to 232.2.48.254232.2.48.25562
197232.2.49.0/26232.2.49.1 to 232.2.49.62232.2.49.6362
198232.2.49.64/26232.2.49.65 to 232.2.49.126232.2.49.12762
199232.2.49.128/26232.2.49.129 to 232.2.49.190232.2.49.19162
200232.2.49.192/26232.2.49.193 to 232.2.49.254232.2.49.25562
201232.2.50.0/26232.2.50.1 to 232.2.50.62232.2.50.6362
202232.2.50.64/26232.2.50.65 to 232.2.50.126232.2.50.12762
203232.2.50.128/26232.2.50.129 to 232.2.50.190232.2.50.19162
204232.2.50.192/26232.2.50.193 to 232.2.50.254232.2.50.25562
205232.2.51.0/26232.2.51.1 to 232.2.51.62232.2.51.6362
206232.2.51.64/26232.2.51.65 to 232.2.51.126232.2.51.12762
207232.2.51.128/26232.2.51.129 to 232.2.51.190232.2.51.19162
208232.2.51.192/26232.2.51.193 to 232.2.51.254232.2.51.25562
209232.2.52.0/26232.2.52.1 to 232.2.52.62232.2.52.6362
210232.2.52.64/26232.2.52.65 to 232.2.52.126232.2.52.12762
211232.2.52.128/26232.2.52.129 to 232.2.52.190232.2.52.19162
212232.2.52.192/26232.2.52.193 to 232.2.52.254232.2.52.25562
213232.2.53.0/26232.2.53.1 to 232.2.53.62232.2.53.6362
214232.2.53.64/26232.2.53.65 to 232.2.53.126232.2.53.12762
215232.2.53.128/26232.2.53.129 to 232.2.53.190232.2.53.19162
216232.2.53.192/26232.2.53.193 to 232.2.53.254232.2.53.25562
217232.2.54.0/26232.2.54.1 to 232.2.54.62232.2.54.6362
218232.2.54.64/26232.2.54.65 to 232.2.54.126232.2.54.12762
219232.2.54.128/26232.2.54.129 to 232.2.54.190232.2.54.19162
220232.2.54.192/26232.2.54.193 to 232.2.54.254232.2.54.25562
221232.2.55.0/26232.2.55.1 to 232.2.55.62232.2.55.6362
222232.2.55.64/26232.2.55.65 to 232.2.55.126232.2.55.12762
223232.2.55.128/26232.2.55.129 to 232.2.55.190232.2.55.19162
224232.2.55.192/26232.2.55.193 to 232.2.55.254232.2.55.25562
225232.2.56.0/26232.2.56.1 to 232.2.56.62232.2.56.6362
226232.2.56.64/26232.2.56.65 to 232.2.56.126232.2.56.12762
227232.2.56.128/26232.2.56.129 to 232.2.56.190232.2.56.19162
228232.2.56.192/26232.2.56.193 to 232.2.56.254232.2.56.25562
229232.2.57.0/26232.2.57.1 to 232.2.57.62232.2.57.6362
230232.2.57.64/26232.2.57.65 to 232.2.57.126232.2.57.12762
231232.2.57.128/26232.2.57.129 to 232.2.57.190232.2.57.19162
232232.2.57.192/26232.2.57.193 to 232.2.57.254232.2.57.25562
233232.2.58.0/26232.2.58.1 to 232.2.58.62232.2.58.6362
234232.2.58.64/26232.2.58.65 to 232.2.58.126232.2.58.12762
235232.2.58.128/26232.2.58.129 to 232.2.58.190232.2.58.19162
236232.2.58.192/26232.2.58.193 to 232.2.58.254232.2.58.25562
237232.2.59.0/26232.2.59.1 to 232.2.59.62232.2.59.6362
238232.2.59.64/26232.2.59.65 to 232.2.59.126232.2.59.12762
239232.2.59.128/26232.2.59.129 to 232.2.59.190232.2.59.19162
240232.2.59.192/26232.2.59.193 to 232.2.59.254232.2.59.25562
241232.2.60.0/26232.2.60.1 to 232.2.60.62232.2.60.6362
242232.2.60.64/26232.2.60.65 to 232.2.60.126232.2.60.12762
243232.2.60.128/26232.2.60.129 to 232.2.60.190232.2.60.19162
244232.2.60.192/26232.2.60.193 to 232.2.60.254232.2.60.25562
245232.2.61.0/26232.2.61.1 to 232.2.61.62232.2.61.6362
246232.2.61.64/26232.2.61.65 to 232.2.61.126232.2.61.12762
247232.2.61.128/26232.2.61.129 to 232.2.61.190232.2.61.19162
248232.2.61.192/26232.2.61.193 to 232.2.61.254232.2.61.25562
249232.2.62.0/26232.2.62.1 to 232.2.62.62232.2.62.6362
250232.2.62.64/26232.2.62.65 to 232.2.62.126232.2.62.12762
251232.2.62.128/26232.2.62.129 to 232.2.62.190232.2.62.19162
252232.2.62.192/26232.2.62.193 to 232.2.62.254232.2.62.25562
253232.2.63.0/26232.2.63.1 to 232.2.63.62232.2.63.6362
254232.2.63.64/26232.2.63.65 to 232.2.63.126232.2.63.12762
255232.2.63.128/26232.2.63.129 to 232.2.63.190232.2.63.19162
256232.2.63.192/26232.2.63.193 to 232.2.63.254232.2.63.25562

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.