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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.

Network150.40.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
150.40.0.0
Broadcast address
150.40.255.255
First usable
150.40.0.1
Last usable
150.40.255.254
Usable hosts
65,534 (65,536 less the network and broadcast addresses)
Subnet mask
255.255.0.0
Wildcard mask
0.0.255.255 (Cisco ACLs, OSPF)
Prefix length
/16
Type
Public public
Old class
B (default /16)
As numbers
Hex 96280000 · Integer 2519203840 to 2519269375
Reverse DNS zone
40.150.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10010110.00101000..00000000.00000000150.40.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network10010110.00101000..00000000.00000000150.40.0.0
Broadcast10010110.00101000..11111111.11111111150.40.255.255
Split into smaller subnets/24
/17 (2)/18 (4)/19 (8)/20 (16)/21 (32)/22 (64)/23 (128)/24 (256)/25 (512)/26 (1,024)/27 (2,048)/28 (4,096)

150.40.0.0/16 makes 256 subnets of /24.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1150.40.0.0/24150.40.0.1 to 150.40.0.254150.40.0.255254
2150.40.1.0/24150.40.1.1 to 150.40.1.254150.40.1.255254
3150.40.2.0/24150.40.2.1 to 150.40.2.254150.40.2.255254
4150.40.3.0/24150.40.3.1 to 150.40.3.254150.40.3.255254
5150.40.4.0/24150.40.4.1 to 150.40.4.254150.40.4.255254
6150.40.5.0/24150.40.5.1 to 150.40.5.254150.40.5.255254
7150.40.6.0/24150.40.6.1 to 150.40.6.254150.40.6.255254
8150.40.7.0/24150.40.7.1 to 150.40.7.254150.40.7.255254
9150.40.8.0/24150.40.8.1 to 150.40.8.254150.40.8.255254
10150.40.9.0/24150.40.9.1 to 150.40.9.254150.40.9.255254
11150.40.10.0/24150.40.10.1 to 150.40.10.254150.40.10.255254
12150.40.11.0/24150.40.11.1 to 150.40.11.254150.40.11.255254
13150.40.12.0/24150.40.12.1 to 150.40.12.254150.40.12.255254
14150.40.13.0/24150.40.13.1 to 150.40.13.254150.40.13.255254
15150.40.14.0/24150.40.14.1 to 150.40.14.254150.40.14.255254
16150.40.15.0/24150.40.15.1 to 150.40.15.254150.40.15.255254
17150.40.16.0/24150.40.16.1 to 150.40.16.254150.40.16.255254
18150.40.17.0/24150.40.17.1 to 150.40.17.254150.40.17.255254
19150.40.18.0/24150.40.18.1 to 150.40.18.254150.40.18.255254
20150.40.19.0/24150.40.19.1 to 150.40.19.254150.40.19.255254
21150.40.20.0/24150.40.20.1 to 150.40.20.254150.40.20.255254
22150.40.21.0/24150.40.21.1 to 150.40.21.254150.40.21.255254
23150.40.22.0/24150.40.22.1 to 150.40.22.254150.40.22.255254
24150.40.23.0/24150.40.23.1 to 150.40.23.254150.40.23.255254
25150.40.24.0/24150.40.24.1 to 150.40.24.254150.40.24.255254
26150.40.25.0/24150.40.25.1 to 150.40.25.254150.40.25.255254
27150.40.26.0/24150.40.26.1 to 150.40.26.254150.40.26.255254
28150.40.27.0/24150.40.27.1 to 150.40.27.254150.40.27.255254
29150.40.28.0/24150.40.28.1 to 150.40.28.254150.40.28.255254
30150.40.29.0/24150.40.29.1 to 150.40.29.254150.40.29.255254
31150.40.30.0/24150.40.30.1 to 150.40.30.254150.40.30.255254
32150.40.31.0/24150.40.31.1 to 150.40.31.254150.40.31.255254
33150.40.32.0/24150.40.32.1 to 150.40.32.254150.40.32.255254
34150.40.33.0/24150.40.33.1 to 150.40.33.254150.40.33.255254
35150.40.34.0/24150.40.34.1 to 150.40.34.254150.40.34.255254
36150.40.35.0/24150.40.35.1 to 150.40.35.254150.40.35.255254
37150.40.36.0/24150.40.36.1 to 150.40.36.254150.40.36.255254
38150.40.37.0/24150.40.37.1 to 150.40.37.254150.40.37.255254
39150.40.38.0/24150.40.38.1 to 150.40.38.254150.40.38.255254
40150.40.39.0/24150.40.39.1 to 150.40.39.254150.40.39.255254
41150.40.40.0/24150.40.40.1 to 150.40.40.254150.40.40.255254
42150.40.41.0/24150.40.41.1 to 150.40.41.254150.40.41.255254
43150.40.42.0/24150.40.42.1 to 150.40.42.254150.40.42.255254
44150.40.43.0/24150.40.43.1 to 150.40.43.254150.40.43.255254
45150.40.44.0/24150.40.44.1 to 150.40.44.254150.40.44.255254
46150.40.45.0/24150.40.45.1 to 150.40.45.254150.40.45.255254
47150.40.46.0/24150.40.46.1 to 150.40.46.254150.40.46.255254
48150.40.47.0/24150.40.47.1 to 150.40.47.254150.40.47.255254
49150.40.48.0/24150.40.48.1 to 150.40.48.254150.40.48.255254
50150.40.49.0/24150.40.49.1 to 150.40.49.254150.40.49.255254
51150.40.50.0/24150.40.50.1 to 150.40.50.254150.40.50.255254
52150.40.51.0/24150.40.51.1 to 150.40.51.254150.40.51.255254
53150.40.52.0/24150.40.52.1 to 150.40.52.254150.40.52.255254
54150.40.53.0/24150.40.53.1 to 150.40.53.254150.40.53.255254
55150.40.54.0/24150.40.54.1 to 150.40.54.254150.40.54.255254
56150.40.55.0/24150.40.55.1 to 150.40.55.254150.40.55.255254
57150.40.56.0/24150.40.56.1 to 150.40.56.254150.40.56.255254
58150.40.57.0/24150.40.57.1 to 150.40.57.254150.40.57.255254
59150.40.58.0/24150.40.58.1 to 150.40.58.254150.40.58.255254
60150.40.59.0/24150.40.59.1 to 150.40.59.254150.40.59.255254
61150.40.60.0/24150.40.60.1 to 150.40.60.254150.40.60.255254
62150.40.61.0/24150.40.61.1 to 150.40.61.254150.40.61.255254
63150.40.62.0/24150.40.62.1 to 150.40.62.254150.40.62.255254
64150.40.63.0/24150.40.63.1 to 150.40.63.254150.40.63.255254
65150.40.64.0/24150.40.64.1 to 150.40.64.254150.40.64.255254
66150.40.65.0/24150.40.65.1 to 150.40.65.254150.40.65.255254
67150.40.66.0/24150.40.66.1 to 150.40.66.254150.40.66.255254
68150.40.67.0/24150.40.67.1 to 150.40.67.254150.40.67.255254
69150.40.68.0/24150.40.68.1 to 150.40.68.254150.40.68.255254
70150.40.69.0/24150.40.69.1 to 150.40.69.254150.40.69.255254
71150.40.70.0/24150.40.70.1 to 150.40.70.254150.40.70.255254
72150.40.71.0/24150.40.71.1 to 150.40.71.254150.40.71.255254
73150.40.72.0/24150.40.72.1 to 150.40.72.254150.40.72.255254
74150.40.73.0/24150.40.73.1 to 150.40.73.254150.40.73.255254
75150.40.74.0/24150.40.74.1 to 150.40.74.254150.40.74.255254
76150.40.75.0/24150.40.75.1 to 150.40.75.254150.40.75.255254
77150.40.76.0/24150.40.76.1 to 150.40.76.254150.40.76.255254
78150.40.77.0/24150.40.77.1 to 150.40.77.254150.40.77.255254
79150.40.78.0/24150.40.78.1 to 150.40.78.254150.40.78.255254
80150.40.79.0/24150.40.79.1 to 150.40.79.254150.40.79.255254
81150.40.80.0/24150.40.80.1 to 150.40.80.254150.40.80.255254
82150.40.81.0/24150.40.81.1 to 150.40.81.254150.40.81.255254
83150.40.82.0/24150.40.82.1 to 150.40.82.254150.40.82.255254
84150.40.83.0/24150.40.83.1 to 150.40.83.254150.40.83.255254
85150.40.84.0/24150.40.84.1 to 150.40.84.254150.40.84.255254
86150.40.85.0/24150.40.85.1 to 150.40.85.254150.40.85.255254
87150.40.86.0/24150.40.86.1 to 150.40.86.254150.40.86.255254
88150.40.87.0/24150.40.87.1 to 150.40.87.254150.40.87.255254
89150.40.88.0/24150.40.88.1 to 150.40.88.254150.40.88.255254
90150.40.89.0/24150.40.89.1 to 150.40.89.254150.40.89.255254
91150.40.90.0/24150.40.90.1 to 150.40.90.254150.40.90.255254
92150.40.91.0/24150.40.91.1 to 150.40.91.254150.40.91.255254
93150.40.92.0/24150.40.92.1 to 150.40.92.254150.40.92.255254
94150.40.93.0/24150.40.93.1 to 150.40.93.254150.40.93.255254
95150.40.94.0/24150.40.94.1 to 150.40.94.254150.40.94.255254
96150.40.95.0/24150.40.95.1 to 150.40.95.254150.40.95.255254
97150.40.96.0/24150.40.96.1 to 150.40.96.254150.40.96.255254
98150.40.97.0/24150.40.97.1 to 150.40.97.254150.40.97.255254
99150.40.98.0/24150.40.98.1 to 150.40.98.254150.40.98.255254
100150.40.99.0/24150.40.99.1 to 150.40.99.254150.40.99.255254
101150.40.100.0/24150.40.100.1 to 150.40.100.254150.40.100.255254
102150.40.101.0/24150.40.101.1 to 150.40.101.254150.40.101.255254
103150.40.102.0/24150.40.102.1 to 150.40.102.254150.40.102.255254
104150.40.103.0/24150.40.103.1 to 150.40.103.254150.40.103.255254
105150.40.104.0/24150.40.104.1 to 150.40.104.254150.40.104.255254
106150.40.105.0/24150.40.105.1 to 150.40.105.254150.40.105.255254
107150.40.106.0/24150.40.106.1 to 150.40.106.254150.40.106.255254
108150.40.107.0/24150.40.107.1 to 150.40.107.254150.40.107.255254
109150.40.108.0/24150.40.108.1 to 150.40.108.254150.40.108.255254
110150.40.109.0/24150.40.109.1 to 150.40.109.254150.40.109.255254
111150.40.110.0/24150.40.110.1 to 150.40.110.254150.40.110.255254
112150.40.111.0/24150.40.111.1 to 150.40.111.254150.40.111.255254
113150.40.112.0/24150.40.112.1 to 150.40.112.254150.40.112.255254
114150.40.113.0/24150.40.113.1 to 150.40.113.254150.40.113.255254
115150.40.114.0/24150.40.114.1 to 150.40.114.254150.40.114.255254
116150.40.115.0/24150.40.115.1 to 150.40.115.254150.40.115.255254
117150.40.116.0/24150.40.116.1 to 150.40.116.254150.40.116.255254
118150.40.117.0/24150.40.117.1 to 150.40.117.254150.40.117.255254
119150.40.118.0/24150.40.118.1 to 150.40.118.254150.40.118.255254
120150.40.119.0/24150.40.119.1 to 150.40.119.254150.40.119.255254
121150.40.120.0/24150.40.120.1 to 150.40.120.254150.40.120.255254
122150.40.121.0/24150.40.121.1 to 150.40.121.254150.40.121.255254
123150.40.122.0/24150.40.122.1 to 150.40.122.254150.40.122.255254
124150.40.123.0/24150.40.123.1 to 150.40.123.254150.40.123.255254
125150.40.124.0/24150.40.124.1 to 150.40.124.254150.40.124.255254
126150.40.125.0/24150.40.125.1 to 150.40.125.254150.40.125.255254
127150.40.126.0/24150.40.126.1 to 150.40.126.254150.40.126.255254
128150.40.127.0/24150.40.127.1 to 150.40.127.254150.40.127.255254
129150.40.128.0/24150.40.128.1 to 150.40.128.254150.40.128.255254
130150.40.129.0/24150.40.129.1 to 150.40.129.254150.40.129.255254
131150.40.130.0/24150.40.130.1 to 150.40.130.254150.40.130.255254
132150.40.131.0/24150.40.131.1 to 150.40.131.254150.40.131.255254
133150.40.132.0/24150.40.132.1 to 150.40.132.254150.40.132.255254
134150.40.133.0/24150.40.133.1 to 150.40.133.254150.40.133.255254
135150.40.134.0/24150.40.134.1 to 150.40.134.254150.40.134.255254
136150.40.135.0/24150.40.135.1 to 150.40.135.254150.40.135.255254
137150.40.136.0/24150.40.136.1 to 150.40.136.254150.40.136.255254
138150.40.137.0/24150.40.137.1 to 150.40.137.254150.40.137.255254
139150.40.138.0/24150.40.138.1 to 150.40.138.254150.40.138.255254
140150.40.139.0/24150.40.139.1 to 150.40.139.254150.40.139.255254
141150.40.140.0/24150.40.140.1 to 150.40.140.254150.40.140.255254
142150.40.141.0/24150.40.141.1 to 150.40.141.254150.40.141.255254
143150.40.142.0/24150.40.142.1 to 150.40.142.254150.40.142.255254
144150.40.143.0/24150.40.143.1 to 150.40.143.254150.40.143.255254
145150.40.144.0/24150.40.144.1 to 150.40.144.254150.40.144.255254
146150.40.145.0/24150.40.145.1 to 150.40.145.254150.40.145.255254
147150.40.146.0/24150.40.146.1 to 150.40.146.254150.40.146.255254
148150.40.147.0/24150.40.147.1 to 150.40.147.254150.40.147.255254
149150.40.148.0/24150.40.148.1 to 150.40.148.254150.40.148.255254
150150.40.149.0/24150.40.149.1 to 150.40.149.254150.40.149.255254
151150.40.150.0/24150.40.150.1 to 150.40.150.254150.40.150.255254
152150.40.151.0/24150.40.151.1 to 150.40.151.254150.40.151.255254
153150.40.152.0/24150.40.152.1 to 150.40.152.254150.40.152.255254
154150.40.153.0/24150.40.153.1 to 150.40.153.254150.40.153.255254
155150.40.154.0/24150.40.154.1 to 150.40.154.254150.40.154.255254
156150.40.155.0/24150.40.155.1 to 150.40.155.254150.40.155.255254
157150.40.156.0/24150.40.156.1 to 150.40.156.254150.40.156.255254
158150.40.157.0/24150.40.157.1 to 150.40.157.254150.40.157.255254
159150.40.158.0/24150.40.158.1 to 150.40.158.254150.40.158.255254
160150.40.159.0/24150.40.159.1 to 150.40.159.254150.40.159.255254
161150.40.160.0/24150.40.160.1 to 150.40.160.254150.40.160.255254
162150.40.161.0/24150.40.161.1 to 150.40.161.254150.40.161.255254
163150.40.162.0/24150.40.162.1 to 150.40.162.254150.40.162.255254
164150.40.163.0/24150.40.163.1 to 150.40.163.254150.40.163.255254
165150.40.164.0/24150.40.164.1 to 150.40.164.254150.40.164.255254
166150.40.165.0/24150.40.165.1 to 150.40.165.254150.40.165.255254
167150.40.166.0/24150.40.166.1 to 150.40.166.254150.40.166.255254
168150.40.167.0/24150.40.167.1 to 150.40.167.254150.40.167.255254
169150.40.168.0/24150.40.168.1 to 150.40.168.254150.40.168.255254
170150.40.169.0/24150.40.169.1 to 150.40.169.254150.40.169.255254
171150.40.170.0/24150.40.170.1 to 150.40.170.254150.40.170.255254
172150.40.171.0/24150.40.171.1 to 150.40.171.254150.40.171.255254
173150.40.172.0/24150.40.172.1 to 150.40.172.254150.40.172.255254
174150.40.173.0/24150.40.173.1 to 150.40.173.254150.40.173.255254
175150.40.174.0/24150.40.174.1 to 150.40.174.254150.40.174.255254
176150.40.175.0/24150.40.175.1 to 150.40.175.254150.40.175.255254
177150.40.176.0/24150.40.176.1 to 150.40.176.254150.40.176.255254
178150.40.177.0/24150.40.177.1 to 150.40.177.254150.40.177.255254
179150.40.178.0/24150.40.178.1 to 150.40.178.254150.40.178.255254
180150.40.179.0/24150.40.179.1 to 150.40.179.254150.40.179.255254
181150.40.180.0/24150.40.180.1 to 150.40.180.254150.40.180.255254
182150.40.181.0/24150.40.181.1 to 150.40.181.254150.40.181.255254
183150.40.182.0/24150.40.182.1 to 150.40.182.254150.40.182.255254
184150.40.183.0/24150.40.183.1 to 150.40.183.254150.40.183.255254
185150.40.184.0/24150.40.184.1 to 150.40.184.254150.40.184.255254
186150.40.185.0/24150.40.185.1 to 150.40.185.254150.40.185.255254
187150.40.186.0/24150.40.186.1 to 150.40.186.254150.40.186.255254
188150.40.187.0/24150.40.187.1 to 150.40.187.254150.40.187.255254
189150.40.188.0/24150.40.188.1 to 150.40.188.254150.40.188.255254
190150.40.189.0/24150.40.189.1 to 150.40.189.254150.40.189.255254
191150.40.190.0/24150.40.190.1 to 150.40.190.254150.40.190.255254
192150.40.191.0/24150.40.191.1 to 150.40.191.254150.40.191.255254
193150.40.192.0/24150.40.192.1 to 150.40.192.254150.40.192.255254
194150.40.193.0/24150.40.193.1 to 150.40.193.254150.40.193.255254
195150.40.194.0/24150.40.194.1 to 150.40.194.254150.40.194.255254
196150.40.195.0/24150.40.195.1 to 150.40.195.254150.40.195.255254
197150.40.196.0/24150.40.196.1 to 150.40.196.254150.40.196.255254
198150.40.197.0/24150.40.197.1 to 150.40.197.254150.40.197.255254
199150.40.198.0/24150.40.198.1 to 150.40.198.254150.40.198.255254
200150.40.199.0/24150.40.199.1 to 150.40.199.254150.40.199.255254
201150.40.200.0/24150.40.200.1 to 150.40.200.254150.40.200.255254
202150.40.201.0/24150.40.201.1 to 150.40.201.254150.40.201.255254
203150.40.202.0/24150.40.202.1 to 150.40.202.254150.40.202.255254
204150.40.203.0/24150.40.203.1 to 150.40.203.254150.40.203.255254
205150.40.204.0/24150.40.204.1 to 150.40.204.254150.40.204.255254
206150.40.205.0/24150.40.205.1 to 150.40.205.254150.40.205.255254
207150.40.206.0/24150.40.206.1 to 150.40.206.254150.40.206.255254
208150.40.207.0/24150.40.207.1 to 150.40.207.254150.40.207.255254
209150.40.208.0/24150.40.208.1 to 150.40.208.254150.40.208.255254
210150.40.209.0/24150.40.209.1 to 150.40.209.254150.40.209.255254
211150.40.210.0/24150.40.210.1 to 150.40.210.254150.40.210.255254
212150.40.211.0/24150.40.211.1 to 150.40.211.254150.40.211.255254
213150.40.212.0/24150.40.212.1 to 150.40.212.254150.40.212.255254
214150.40.213.0/24150.40.213.1 to 150.40.213.254150.40.213.255254
215150.40.214.0/24150.40.214.1 to 150.40.214.254150.40.214.255254
216150.40.215.0/24150.40.215.1 to 150.40.215.254150.40.215.255254
217150.40.216.0/24150.40.216.1 to 150.40.216.254150.40.216.255254
218150.40.217.0/24150.40.217.1 to 150.40.217.254150.40.217.255254
219150.40.218.0/24150.40.218.1 to 150.40.218.254150.40.218.255254
220150.40.219.0/24150.40.219.1 to 150.40.219.254150.40.219.255254
221150.40.220.0/24150.40.220.1 to 150.40.220.254150.40.220.255254
222150.40.221.0/24150.40.221.1 to 150.40.221.254150.40.221.255254
223150.40.222.0/24150.40.222.1 to 150.40.222.254150.40.222.255254
224150.40.223.0/24150.40.223.1 to 150.40.223.254150.40.223.255254
225150.40.224.0/24150.40.224.1 to 150.40.224.254150.40.224.255254
226150.40.225.0/24150.40.225.1 to 150.40.225.254150.40.225.255254
227150.40.226.0/24150.40.226.1 to 150.40.226.254150.40.226.255254
228150.40.227.0/24150.40.227.1 to 150.40.227.254150.40.227.255254
229150.40.228.0/24150.40.228.1 to 150.40.228.254150.40.228.255254
230150.40.229.0/24150.40.229.1 to 150.40.229.254150.40.229.255254
231150.40.230.0/24150.40.230.1 to 150.40.230.254150.40.230.255254
232150.40.231.0/24150.40.231.1 to 150.40.231.254150.40.231.255254
233150.40.232.0/24150.40.232.1 to 150.40.232.254150.40.232.255254
234150.40.233.0/24150.40.233.1 to 150.40.233.254150.40.233.255254
235150.40.234.0/24150.40.234.1 to 150.40.234.254150.40.234.255254
236150.40.235.0/24150.40.235.1 to 150.40.235.254150.40.235.255254
237150.40.236.0/24150.40.236.1 to 150.40.236.254150.40.236.255254
238150.40.237.0/24150.40.237.1 to 150.40.237.254150.40.237.255254
239150.40.238.0/24150.40.238.1 to 150.40.238.254150.40.238.255254
240150.40.239.0/24150.40.239.1 to 150.40.239.254150.40.239.255254
241150.40.240.0/24150.40.240.1 to 150.40.240.254150.40.240.255254
242150.40.241.0/24150.40.241.1 to 150.40.241.254150.40.241.255254
243150.40.242.0/24150.40.242.1 to 150.40.242.254150.40.242.255254
244150.40.243.0/24150.40.243.1 to 150.40.243.254150.40.243.255254
245150.40.244.0/24150.40.244.1 to 150.40.244.254150.40.244.255254
246150.40.245.0/24150.40.245.1 to 150.40.245.254150.40.245.255254
247150.40.246.0/24150.40.246.1 to 150.40.246.254150.40.246.255254
248150.40.247.0/24150.40.247.1 to 150.40.247.254150.40.247.255254
249150.40.248.0/24150.40.248.1 to 150.40.248.254150.40.248.255254
250150.40.249.0/24150.40.249.1 to 150.40.249.254150.40.249.255254
251150.40.250.0/24150.40.250.1 to 150.40.250.254150.40.250.255254
252150.40.251.0/24150.40.251.1 to 150.40.251.254150.40.251.255254
253150.40.252.0/24150.40.252.1 to 150.40.252.254150.40.252.255254
254150.40.253.0/24150.40.253.1 to 150.40.253.254150.40.253.255254
255150.40.254.0/24150.40.254.1 to 150.40.254.254150.40.254.255254
256150.40.255.0/24150.40.255.1 to 150.40.255.254150.40.255.255254

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.