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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.

Network158.75.0.0/17
Usable hosts32,766
Subnet mask255.255.128.0
Addresses32,768
Network address
158.75.0.0
Broadcast address
158.75.127.255
First usable
158.75.0.1
Last usable
158.75.127.254
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
Public public
Old class
B (default /16)
As numbers
Hex 9E4B0000 · Integer 2655715328 to 2655748095
Reverse DNS zones
0.75.158.in-addr.arpa
1.75.158.in-addr.arpa
2.75.158.in-addr.arpa
3.75.158.in-addr.arpa
4.75.158.in-addr.arpa
5.75.158.in-addr.arpa
6.75.158.in-addr.arpa
7.75.158.in-addr.arpa
8.75.158.in-addr.arpa
9.75.158.in-addr.arpa
10.75.158.in-addr.arpa
11.75.158.in-addr.arpa
12.75.158.in-addr.arpa
13.75.158.in-addr.arpa
14.75.158.in-addr.arpa
15.75.158.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
Address10011110.01001011.00000000.00000000158.75.0.0
Subnet mask11111111.11111111.10000000.00000000255.255.128.0
Network10011110.01001011.00000000.00000000158.75.0.0
Broadcast10011110.01001011.01111111.11111111158.75.127.255
Split into smaller subnets/28
/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)

158.75.0.0/17 makes 2,048 subnets of /28; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1158.75.0.0/28158.75.0.1 to 158.75.0.14158.75.0.1514
2158.75.0.16/28158.75.0.17 to 158.75.0.30158.75.0.3114
3158.75.0.32/28158.75.0.33 to 158.75.0.46158.75.0.4714
4158.75.0.48/28158.75.0.49 to 158.75.0.62158.75.0.6314
5158.75.0.64/28158.75.0.65 to 158.75.0.78158.75.0.7914
6158.75.0.80/28158.75.0.81 to 158.75.0.94158.75.0.9514
7158.75.0.96/28158.75.0.97 to 158.75.0.110158.75.0.11114
8158.75.0.112/28158.75.0.113 to 158.75.0.126158.75.0.12714
9158.75.0.128/28158.75.0.129 to 158.75.0.142158.75.0.14314
10158.75.0.144/28158.75.0.145 to 158.75.0.158158.75.0.15914
11158.75.0.160/28158.75.0.161 to 158.75.0.174158.75.0.17514
12158.75.0.176/28158.75.0.177 to 158.75.0.190158.75.0.19114
13158.75.0.192/28158.75.0.193 to 158.75.0.206158.75.0.20714
14158.75.0.208/28158.75.0.209 to 158.75.0.222158.75.0.22314
15158.75.0.224/28158.75.0.225 to 158.75.0.238158.75.0.23914
16158.75.0.240/28158.75.0.241 to 158.75.0.254158.75.0.25514
17158.75.1.0/28158.75.1.1 to 158.75.1.14158.75.1.1514
18158.75.1.16/28158.75.1.17 to 158.75.1.30158.75.1.3114
19158.75.1.32/28158.75.1.33 to 158.75.1.46158.75.1.4714
20158.75.1.48/28158.75.1.49 to 158.75.1.62158.75.1.6314
21158.75.1.64/28158.75.1.65 to 158.75.1.78158.75.1.7914
22158.75.1.80/28158.75.1.81 to 158.75.1.94158.75.1.9514
23158.75.1.96/28158.75.1.97 to 158.75.1.110158.75.1.11114
24158.75.1.112/28158.75.1.113 to 158.75.1.126158.75.1.12714
25158.75.1.128/28158.75.1.129 to 158.75.1.142158.75.1.14314
26158.75.1.144/28158.75.1.145 to 158.75.1.158158.75.1.15914
27158.75.1.160/28158.75.1.161 to 158.75.1.174158.75.1.17514
28158.75.1.176/28158.75.1.177 to 158.75.1.190158.75.1.19114
29158.75.1.192/28158.75.1.193 to 158.75.1.206158.75.1.20714
30158.75.1.208/28158.75.1.209 to 158.75.1.222158.75.1.22314
31158.75.1.224/28158.75.1.225 to 158.75.1.238158.75.1.23914
32158.75.1.240/28158.75.1.241 to 158.75.1.254158.75.1.25514
33158.75.2.0/28158.75.2.1 to 158.75.2.14158.75.2.1514
34158.75.2.16/28158.75.2.17 to 158.75.2.30158.75.2.3114
35158.75.2.32/28158.75.2.33 to 158.75.2.46158.75.2.4714
36158.75.2.48/28158.75.2.49 to 158.75.2.62158.75.2.6314
37158.75.2.64/28158.75.2.65 to 158.75.2.78158.75.2.7914
38158.75.2.80/28158.75.2.81 to 158.75.2.94158.75.2.9514
39158.75.2.96/28158.75.2.97 to 158.75.2.110158.75.2.11114
40158.75.2.112/28158.75.2.113 to 158.75.2.126158.75.2.12714
41158.75.2.128/28158.75.2.129 to 158.75.2.142158.75.2.14314
42158.75.2.144/28158.75.2.145 to 158.75.2.158158.75.2.15914
43158.75.2.160/28158.75.2.161 to 158.75.2.174158.75.2.17514
44158.75.2.176/28158.75.2.177 to 158.75.2.190158.75.2.19114
45158.75.2.192/28158.75.2.193 to 158.75.2.206158.75.2.20714
46158.75.2.208/28158.75.2.209 to 158.75.2.222158.75.2.22314
47158.75.2.224/28158.75.2.225 to 158.75.2.238158.75.2.23914
48158.75.2.240/28158.75.2.241 to 158.75.2.254158.75.2.25514
49158.75.3.0/28158.75.3.1 to 158.75.3.14158.75.3.1514
50158.75.3.16/28158.75.3.17 to 158.75.3.30158.75.3.3114
51158.75.3.32/28158.75.3.33 to 158.75.3.46158.75.3.4714
52158.75.3.48/28158.75.3.49 to 158.75.3.62158.75.3.6314
53158.75.3.64/28158.75.3.65 to 158.75.3.78158.75.3.7914
54158.75.3.80/28158.75.3.81 to 158.75.3.94158.75.3.9514
55158.75.3.96/28158.75.3.97 to 158.75.3.110158.75.3.11114
56158.75.3.112/28158.75.3.113 to 158.75.3.126158.75.3.12714
57158.75.3.128/28158.75.3.129 to 158.75.3.142158.75.3.14314
58158.75.3.144/28158.75.3.145 to 158.75.3.158158.75.3.15914
59158.75.3.160/28158.75.3.161 to 158.75.3.174158.75.3.17514
60158.75.3.176/28158.75.3.177 to 158.75.3.190158.75.3.19114
61158.75.3.192/28158.75.3.193 to 158.75.3.206158.75.3.20714
62158.75.3.208/28158.75.3.209 to 158.75.3.222158.75.3.22314
63158.75.3.224/28158.75.3.225 to 158.75.3.238158.75.3.23914
64158.75.3.240/28158.75.3.241 to 158.75.3.254158.75.3.25514
65158.75.4.0/28158.75.4.1 to 158.75.4.14158.75.4.1514
66158.75.4.16/28158.75.4.17 to 158.75.4.30158.75.4.3114
67158.75.4.32/28158.75.4.33 to 158.75.4.46158.75.4.4714
68158.75.4.48/28158.75.4.49 to 158.75.4.62158.75.4.6314
69158.75.4.64/28158.75.4.65 to 158.75.4.78158.75.4.7914
70158.75.4.80/28158.75.4.81 to 158.75.4.94158.75.4.9514
71158.75.4.96/28158.75.4.97 to 158.75.4.110158.75.4.11114
72158.75.4.112/28158.75.4.113 to 158.75.4.126158.75.4.12714
73158.75.4.128/28158.75.4.129 to 158.75.4.142158.75.4.14314
74158.75.4.144/28158.75.4.145 to 158.75.4.158158.75.4.15914
75158.75.4.160/28158.75.4.161 to 158.75.4.174158.75.4.17514
76158.75.4.176/28158.75.4.177 to 158.75.4.190158.75.4.19114
77158.75.4.192/28158.75.4.193 to 158.75.4.206158.75.4.20714
78158.75.4.208/28158.75.4.209 to 158.75.4.222158.75.4.22314
79158.75.4.224/28158.75.4.225 to 158.75.4.238158.75.4.23914
80158.75.4.240/28158.75.4.241 to 158.75.4.254158.75.4.25514
81158.75.5.0/28158.75.5.1 to 158.75.5.14158.75.5.1514
82158.75.5.16/28158.75.5.17 to 158.75.5.30158.75.5.3114
83158.75.5.32/28158.75.5.33 to 158.75.5.46158.75.5.4714
84158.75.5.48/28158.75.5.49 to 158.75.5.62158.75.5.6314
85158.75.5.64/28158.75.5.65 to 158.75.5.78158.75.5.7914
86158.75.5.80/28158.75.5.81 to 158.75.5.94158.75.5.9514
87158.75.5.96/28158.75.5.97 to 158.75.5.110158.75.5.11114
88158.75.5.112/28158.75.5.113 to 158.75.5.126158.75.5.12714
89158.75.5.128/28158.75.5.129 to 158.75.5.142158.75.5.14314
90158.75.5.144/28158.75.5.145 to 158.75.5.158158.75.5.15914
91158.75.5.160/28158.75.5.161 to 158.75.5.174158.75.5.17514
92158.75.5.176/28158.75.5.177 to 158.75.5.190158.75.5.19114
93158.75.5.192/28158.75.5.193 to 158.75.5.206158.75.5.20714
94158.75.5.208/28158.75.5.209 to 158.75.5.222158.75.5.22314
95158.75.5.224/28158.75.5.225 to 158.75.5.238158.75.5.23914
96158.75.5.240/28158.75.5.241 to 158.75.5.254158.75.5.25514
97158.75.6.0/28158.75.6.1 to 158.75.6.14158.75.6.1514
98158.75.6.16/28158.75.6.17 to 158.75.6.30158.75.6.3114
99158.75.6.32/28158.75.6.33 to 158.75.6.46158.75.6.4714
100158.75.6.48/28158.75.6.49 to 158.75.6.62158.75.6.6314
101158.75.6.64/28158.75.6.65 to 158.75.6.78158.75.6.7914
102158.75.6.80/28158.75.6.81 to 158.75.6.94158.75.6.9514
103158.75.6.96/28158.75.6.97 to 158.75.6.110158.75.6.11114
104158.75.6.112/28158.75.6.113 to 158.75.6.126158.75.6.12714
105158.75.6.128/28158.75.6.129 to 158.75.6.142158.75.6.14314
106158.75.6.144/28158.75.6.145 to 158.75.6.158158.75.6.15914
107158.75.6.160/28158.75.6.161 to 158.75.6.174158.75.6.17514
108158.75.6.176/28158.75.6.177 to 158.75.6.190158.75.6.19114
109158.75.6.192/28158.75.6.193 to 158.75.6.206158.75.6.20714
110158.75.6.208/28158.75.6.209 to 158.75.6.222158.75.6.22314
111158.75.6.224/28158.75.6.225 to 158.75.6.238158.75.6.23914
112158.75.6.240/28158.75.6.241 to 158.75.6.254158.75.6.25514
113158.75.7.0/28158.75.7.1 to 158.75.7.14158.75.7.1514
114158.75.7.16/28158.75.7.17 to 158.75.7.30158.75.7.3114
115158.75.7.32/28158.75.7.33 to 158.75.7.46158.75.7.4714
116158.75.7.48/28158.75.7.49 to 158.75.7.62158.75.7.6314
117158.75.7.64/28158.75.7.65 to 158.75.7.78158.75.7.7914
118158.75.7.80/28158.75.7.81 to 158.75.7.94158.75.7.9514
119158.75.7.96/28158.75.7.97 to 158.75.7.110158.75.7.11114
120158.75.7.112/28158.75.7.113 to 158.75.7.126158.75.7.12714
121158.75.7.128/28158.75.7.129 to 158.75.7.142158.75.7.14314
122158.75.7.144/28158.75.7.145 to 158.75.7.158158.75.7.15914
123158.75.7.160/28158.75.7.161 to 158.75.7.174158.75.7.17514
124158.75.7.176/28158.75.7.177 to 158.75.7.190158.75.7.19114
125158.75.7.192/28158.75.7.193 to 158.75.7.206158.75.7.20714
126158.75.7.208/28158.75.7.209 to 158.75.7.222158.75.7.22314
127158.75.7.224/28158.75.7.225 to 158.75.7.238158.75.7.23914
128158.75.7.240/28158.75.7.241 to 158.75.7.254158.75.7.25514
129158.75.8.0/28158.75.8.1 to 158.75.8.14158.75.8.1514
130158.75.8.16/28158.75.8.17 to 158.75.8.30158.75.8.3114
131158.75.8.32/28158.75.8.33 to 158.75.8.46158.75.8.4714
132158.75.8.48/28158.75.8.49 to 158.75.8.62158.75.8.6314
133158.75.8.64/28158.75.8.65 to 158.75.8.78158.75.8.7914
134158.75.8.80/28158.75.8.81 to 158.75.8.94158.75.8.9514
135158.75.8.96/28158.75.8.97 to 158.75.8.110158.75.8.11114
136158.75.8.112/28158.75.8.113 to 158.75.8.126158.75.8.12714
137158.75.8.128/28158.75.8.129 to 158.75.8.142158.75.8.14314
138158.75.8.144/28158.75.8.145 to 158.75.8.158158.75.8.15914
139158.75.8.160/28158.75.8.161 to 158.75.8.174158.75.8.17514
140158.75.8.176/28158.75.8.177 to 158.75.8.190158.75.8.19114
141158.75.8.192/28158.75.8.193 to 158.75.8.206158.75.8.20714
142158.75.8.208/28158.75.8.209 to 158.75.8.222158.75.8.22314
143158.75.8.224/28158.75.8.225 to 158.75.8.238158.75.8.23914
144158.75.8.240/28158.75.8.241 to 158.75.8.254158.75.8.25514
145158.75.9.0/28158.75.9.1 to 158.75.9.14158.75.9.1514
146158.75.9.16/28158.75.9.17 to 158.75.9.30158.75.9.3114
147158.75.9.32/28158.75.9.33 to 158.75.9.46158.75.9.4714
148158.75.9.48/28158.75.9.49 to 158.75.9.62158.75.9.6314
149158.75.9.64/28158.75.9.65 to 158.75.9.78158.75.9.7914
150158.75.9.80/28158.75.9.81 to 158.75.9.94158.75.9.9514
151158.75.9.96/28158.75.9.97 to 158.75.9.110158.75.9.11114
152158.75.9.112/28158.75.9.113 to 158.75.9.126158.75.9.12714
153158.75.9.128/28158.75.9.129 to 158.75.9.142158.75.9.14314
154158.75.9.144/28158.75.9.145 to 158.75.9.158158.75.9.15914
155158.75.9.160/28158.75.9.161 to 158.75.9.174158.75.9.17514
156158.75.9.176/28158.75.9.177 to 158.75.9.190158.75.9.19114
157158.75.9.192/28158.75.9.193 to 158.75.9.206158.75.9.20714
158158.75.9.208/28158.75.9.209 to 158.75.9.222158.75.9.22314
159158.75.9.224/28158.75.9.225 to 158.75.9.238158.75.9.23914
160158.75.9.240/28158.75.9.241 to 158.75.9.254158.75.9.25514
161158.75.10.0/28158.75.10.1 to 158.75.10.14158.75.10.1514
162158.75.10.16/28158.75.10.17 to 158.75.10.30158.75.10.3114
163158.75.10.32/28158.75.10.33 to 158.75.10.46158.75.10.4714
164158.75.10.48/28158.75.10.49 to 158.75.10.62158.75.10.6314
165158.75.10.64/28158.75.10.65 to 158.75.10.78158.75.10.7914
166158.75.10.80/28158.75.10.81 to 158.75.10.94158.75.10.9514
167158.75.10.96/28158.75.10.97 to 158.75.10.110158.75.10.11114
168158.75.10.112/28158.75.10.113 to 158.75.10.126158.75.10.12714
169158.75.10.128/28158.75.10.129 to 158.75.10.142158.75.10.14314
170158.75.10.144/28158.75.10.145 to 158.75.10.158158.75.10.15914
171158.75.10.160/28158.75.10.161 to 158.75.10.174158.75.10.17514
172158.75.10.176/28158.75.10.177 to 158.75.10.190158.75.10.19114
173158.75.10.192/28158.75.10.193 to 158.75.10.206158.75.10.20714
174158.75.10.208/28158.75.10.209 to 158.75.10.222158.75.10.22314
175158.75.10.224/28158.75.10.225 to 158.75.10.238158.75.10.23914
176158.75.10.240/28158.75.10.241 to 158.75.10.254158.75.10.25514
177158.75.11.0/28158.75.11.1 to 158.75.11.14158.75.11.1514
178158.75.11.16/28158.75.11.17 to 158.75.11.30158.75.11.3114
179158.75.11.32/28158.75.11.33 to 158.75.11.46158.75.11.4714
180158.75.11.48/28158.75.11.49 to 158.75.11.62158.75.11.6314
181158.75.11.64/28158.75.11.65 to 158.75.11.78158.75.11.7914
182158.75.11.80/28158.75.11.81 to 158.75.11.94158.75.11.9514
183158.75.11.96/28158.75.11.97 to 158.75.11.110158.75.11.11114
184158.75.11.112/28158.75.11.113 to 158.75.11.126158.75.11.12714
185158.75.11.128/28158.75.11.129 to 158.75.11.142158.75.11.14314
186158.75.11.144/28158.75.11.145 to 158.75.11.158158.75.11.15914
187158.75.11.160/28158.75.11.161 to 158.75.11.174158.75.11.17514
188158.75.11.176/28158.75.11.177 to 158.75.11.190158.75.11.19114
189158.75.11.192/28158.75.11.193 to 158.75.11.206158.75.11.20714
190158.75.11.208/28158.75.11.209 to 158.75.11.222158.75.11.22314
191158.75.11.224/28158.75.11.225 to 158.75.11.238158.75.11.23914
192158.75.11.240/28158.75.11.241 to 158.75.11.254158.75.11.25514
193158.75.12.0/28158.75.12.1 to 158.75.12.14158.75.12.1514
194158.75.12.16/28158.75.12.17 to 158.75.12.30158.75.12.3114
195158.75.12.32/28158.75.12.33 to 158.75.12.46158.75.12.4714
196158.75.12.48/28158.75.12.49 to 158.75.12.62158.75.12.6314
197158.75.12.64/28158.75.12.65 to 158.75.12.78158.75.12.7914
198158.75.12.80/28158.75.12.81 to 158.75.12.94158.75.12.9514
199158.75.12.96/28158.75.12.97 to 158.75.12.110158.75.12.11114
200158.75.12.112/28158.75.12.113 to 158.75.12.126158.75.12.12714
201158.75.12.128/28158.75.12.129 to 158.75.12.142158.75.12.14314
202158.75.12.144/28158.75.12.145 to 158.75.12.158158.75.12.15914
203158.75.12.160/28158.75.12.161 to 158.75.12.174158.75.12.17514
204158.75.12.176/28158.75.12.177 to 158.75.12.190158.75.12.19114
205158.75.12.192/28158.75.12.193 to 158.75.12.206158.75.12.20714
206158.75.12.208/28158.75.12.209 to 158.75.12.222158.75.12.22314
207158.75.12.224/28158.75.12.225 to 158.75.12.238158.75.12.23914
208158.75.12.240/28158.75.12.241 to 158.75.12.254158.75.12.25514
209158.75.13.0/28158.75.13.1 to 158.75.13.14158.75.13.1514
210158.75.13.16/28158.75.13.17 to 158.75.13.30158.75.13.3114
211158.75.13.32/28158.75.13.33 to 158.75.13.46158.75.13.4714
212158.75.13.48/28158.75.13.49 to 158.75.13.62158.75.13.6314
213158.75.13.64/28158.75.13.65 to 158.75.13.78158.75.13.7914
214158.75.13.80/28158.75.13.81 to 158.75.13.94158.75.13.9514
215158.75.13.96/28158.75.13.97 to 158.75.13.110158.75.13.11114
216158.75.13.112/28158.75.13.113 to 158.75.13.126158.75.13.12714
217158.75.13.128/28158.75.13.129 to 158.75.13.142158.75.13.14314
218158.75.13.144/28158.75.13.145 to 158.75.13.158158.75.13.15914
219158.75.13.160/28158.75.13.161 to 158.75.13.174158.75.13.17514
220158.75.13.176/28158.75.13.177 to 158.75.13.190158.75.13.19114
221158.75.13.192/28158.75.13.193 to 158.75.13.206158.75.13.20714
222158.75.13.208/28158.75.13.209 to 158.75.13.222158.75.13.22314
223158.75.13.224/28158.75.13.225 to 158.75.13.238158.75.13.23914
224158.75.13.240/28158.75.13.241 to 158.75.13.254158.75.13.25514
225158.75.14.0/28158.75.14.1 to 158.75.14.14158.75.14.1514
226158.75.14.16/28158.75.14.17 to 158.75.14.30158.75.14.3114
227158.75.14.32/28158.75.14.33 to 158.75.14.46158.75.14.4714
228158.75.14.48/28158.75.14.49 to 158.75.14.62158.75.14.6314
229158.75.14.64/28158.75.14.65 to 158.75.14.78158.75.14.7914
230158.75.14.80/28158.75.14.81 to 158.75.14.94158.75.14.9514
231158.75.14.96/28158.75.14.97 to 158.75.14.110158.75.14.11114
232158.75.14.112/28158.75.14.113 to 158.75.14.126158.75.14.12714
233158.75.14.128/28158.75.14.129 to 158.75.14.142158.75.14.14314
234158.75.14.144/28158.75.14.145 to 158.75.14.158158.75.14.15914
235158.75.14.160/28158.75.14.161 to 158.75.14.174158.75.14.17514
236158.75.14.176/28158.75.14.177 to 158.75.14.190158.75.14.19114
237158.75.14.192/28158.75.14.193 to 158.75.14.206158.75.14.20714
238158.75.14.208/28158.75.14.209 to 158.75.14.222158.75.14.22314
239158.75.14.224/28158.75.14.225 to 158.75.14.238158.75.14.23914
240158.75.14.240/28158.75.14.241 to 158.75.14.254158.75.14.25514
241158.75.15.0/28158.75.15.1 to 158.75.15.14158.75.15.1514
242158.75.15.16/28158.75.15.17 to 158.75.15.30158.75.15.3114
243158.75.15.32/28158.75.15.33 to 158.75.15.46158.75.15.4714
244158.75.15.48/28158.75.15.49 to 158.75.15.62158.75.15.6314
245158.75.15.64/28158.75.15.65 to 158.75.15.78158.75.15.7914
246158.75.15.80/28158.75.15.81 to 158.75.15.94158.75.15.9514
247158.75.15.96/28158.75.15.97 to 158.75.15.110158.75.15.11114
248158.75.15.112/28158.75.15.113 to 158.75.15.126158.75.15.12714
249158.75.15.128/28158.75.15.129 to 158.75.15.142158.75.15.14314
250158.75.15.144/28158.75.15.145 to 158.75.15.158158.75.15.15914
251158.75.15.160/28158.75.15.161 to 158.75.15.174158.75.15.17514
252158.75.15.176/28158.75.15.177 to 158.75.15.190158.75.15.19114
253158.75.15.192/28158.75.15.193 to 158.75.15.206158.75.15.20714
254158.75.15.208/28158.75.15.209 to 158.75.15.222158.75.15.22314
255158.75.15.224/28158.75.15.225 to 158.75.15.238158.75.15.23914
256158.75.15.240/28158.75.15.241 to 158.75.15.254158.75.15.25514

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.