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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.

Network210.72.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
210.72.0.0
Broadcast address
210.79.255.255
First usable
210.72.0.1
Last usable
210.79.255.254
Usable hosts
524,286 (524,288 less the network and broadcast addresses)
Subnet mask
255.248.0.0
Wildcard mask
0.7.255.255 (Cisco ACLs, OSPF)
Prefix length
/13
Type
Public public
Old class
C (default /24)
As numbers
Hex D2480000 · Integer 3527933952 to 3528458239
Reverse DNS zones
72.210.in-addr.arpa
73.210.in-addr.arpa
74.210.in-addr.arpa
75.210.in-addr.arpa
76.210.in-addr.arpa
77.210.in-addr.arpa
78.210.in-addr.arpa
79.210.in-addr.arpa
/13 is not on a 8-bit boundary, so it takes 8 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11010010.01001000.00000000.00000000210.72.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network11010010.01001000.00000000.00000000210.72.0.0
Broadcast11010010.01001111.11111111.11111111210.79.255.255
Split into smaller subnets/23
/14 (2)/15 (4)/16 (8)/17 (16)/18 (32)/19 (64)/20 (128)/21 (256)/22 (512)/23 (1,024)/24 (2,048)/25 (4,096)

210.72.0.0/13 makes 1,024 subnets of /23; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1210.72.0.0/23210.72.0.1 to 210.72.1.254210.72.1.255510
2210.72.2.0/23210.72.2.1 to 210.72.3.254210.72.3.255510
3210.72.4.0/23210.72.4.1 to 210.72.5.254210.72.5.255510
4210.72.6.0/23210.72.6.1 to 210.72.7.254210.72.7.255510
5210.72.8.0/23210.72.8.1 to 210.72.9.254210.72.9.255510
6210.72.10.0/23210.72.10.1 to 210.72.11.254210.72.11.255510
7210.72.12.0/23210.72.12.1 to 210.72.13.254210.72.13.255510
8210.72.14.0/23210.72.14.1 to 210.72.15.254210.72.15.255510
9210.72.16.0/23210.72.16.1 to 210.72.17.254210.72.17.255510
10210.72.18.0/23210.72.18.1 to 210.72.19.254210.72.19.255510
11210.72.20.0/23210.72.20.1 to 210.72.21.254210.72.21.255510
12210.72.22.0/23210.72.22.1 to 210.72.23.254210.72.23.255510
13210.72.24.0/23210.72.24.1 to 210.72.25.254210.72.25.255510
14210.72.26.0/23210.72.26.1 to 210.72.27.254210.72.27.255510
15210.72.28.0/23210.72.28.1 to 210.72.29.254210.72.29.255510
16210.72.30.0/23210.72.30.1 to 210.72.31.254210.72.31.255510
17210.72.32.0/23210.72.32.1 to 210.72.33.254210.72.33.255510
18210.72.34.0/23210.72.34.1 to 210.72.35.254210.72.35.255510
19210.72.36.0/23210.72.36.1 to 210.72.37.254210.72.37.255510
20210.72.38.0/23210.72.38.1 to 210.72.39.254210.72.39.255510
21210.72.40.0/23210.72.40.1 to 210.72.41.254210.72.41.255510
22210.72.42.0/23210.72.42.1 to 210.72.43.254210.72.43.255510
23210.72.44.0/23210.72.44.1 to 210.72.45.254210.72.45.255510
24210.72.46.0/23210.72.46.1 to 210.72.47.254210.72.47.255510
25210.72.48.0/23210.72.48.1 to 210.72.49.254210.72.49.255510
26210.72.50.0/23210.72.50.1 to 210.72.51.254210.72.51.255510
27210.72.52.0/23210.72.52.1 to 210.72.53.254210.72.53.255510
28210.72.54.0/23210.72.54.1 to 210.72.55.254210.72.55.255510
29210.72.56.0/23210.72.56.1 to 210.72.57.254210.72.57.255510
30210.72.58.0/23210.72.58.1 to 210.72.59.254210.72.59.255510
31210.72.60.0/23210.72.60.1 to 210.72.61.254210.72.61.255510
32210.72.62.0/23210.72.62.1 to 210.72.63.254210.72.63.255510
33210.72.64.0/23210.72.64.1 to 210.72.65.254210.72.65.255510
34210.72.66.0/23210.72.66.1 to 210.72.67.254210.72.67.255510
35210.72.68.0/23210.72.68.1 to 210.72.69.254210.72.69.255510
36210.72.70.0/23210.72.70.1 to 210.72.71.254210.72.71.255510
37210.72.72.0/23210.72.72.1 to 210.72.73.254210.72.73.255510
38210.72.74.0/23210.72.74.1 to 210.72.75.254210.72.75.255510
39210.72.76.0/23210.72.76.1 to 210.72.77.254210.72.77.255510
40210.72.78.0/23210.72.78.1 to 210.72.79.254210.72.79.255510
41210.72.80.0/23210.72.80.1 to 210.72.81.254210.72.81.255510
42210.72.82.0/23210.72.82.1 to 210.72.83.254210.72.83.255510
43210.72.84.0/23210.72.84.1 to 210.72.85.254210.72.85.255510
44210.72.86.0/23210.72.86.1 to 210.72.87.254210.72.87.255510
45210.72.88.0/23210.72.88.1 to 210.72.89.254210.72.89.255510
46210.72.90.0/23210.72.90.1 to 210.72.91.254210.72.91.255510
47210.72.92.0/23210.72.92.1 to 210.72.93.254210.72.93.255510
48210.72.94.0/23210.72.94.1 to 210.72.95.254210.72.95.255510
49210.72.96.0/23210.72.96.1 to 210.72.97.254210.72.97.255510
50210.72.98.0/23210.72.98.1 to 210.72.99.254210.72.99.255510
51210.72.100.0/23210.72.100.1 to 210.72.101.254210.72.101.255510
52210.72.102.0/23210.72.102.1 to 210.72.103.254210.72.103.255510
53210.72.104.0/23210.72.104.1 to 210.72.105.254210.72.105.255510
54210.72.106.0/23210.72.106.1 to 210.72.107.254210.72.107.255510
55210.72.108.0/23210.72.108.1 to 210.72.109.254210.72.109.255510
56210.72.110.0/23210.72.110.1 to 210.72.111.254210.72.111.255510
57210.72.112.0/23210.72.112.1 to 210.72.113.254210.72.113.255510
58210.72.114.0/23210.72.114.1 to 210.72.115.254210.72.115.255510
59210.72.116.0/23210.72.116.1 to 210.72.117.254210.72.117.255510
60210.72.118.0/23210.72.118.1 to 210.72.119.254210.72.119.255510
61210.72.120.0/23210.72.120.1 to 210.72.121.254210.72.121.255510
62210.72.122.0/23210.72.122.1 to 210.72.123.254210.72.123.255510
63210.72.124.0/23210.72.124.1 to 210.72.125.254210.72.125.255510
64210.72.126.0/23210.72.126.1 to 210.72.127.254210.72.127.255510
65210.72.128.0/23210.72.128.1 to 210.72.129.254210.72.129.255510
66210.72.130.0/23210.72.130.1 to 210.72.131.254210.72.131.255510
67210.72.132.0/23210.72.132.1 to 210.72.133.254210.72.133.255510
68210.72.134.0/23210.72.134.1 to 210.72.135.254210.72.135.255510
69210.72.136.0/23210.72.136.1 to 210.72.137.254210.72.137.255510
70210.72.138.0/23210.72.138.1 to 210.72.139.254210.72.139.255510
71210.72.140.0/23210.72.140.1 to 210.72.141.254210.72.141.255510
72210.72.142.0/23210.72.142.1 to 210.72.143.254210.72.143.255510
73210.72.144.0/23210.72.144.1 to 210.72.145.254210.72.145.255510
74210.72.146.0/23210.72.146.1 to 210.72.147.254210.72.147.255510
75210.72.148.0/23210.72.148.1 to 210.72.149.254210.72.149.255510
76210.72.150.0/23210.72.150.1 to 210.72.151.254210.72.151.255510
77210.72.152.0/23210.72.152.1 to 210.72.153.254210.72.153.255510
78210.72.154.0/23210.72.154.1 to 210.72.155.254210.72.155.255510
79210.72.156.0/23210.72.156.1 to 210.72.157.254210.72.157.255510
80210.72.158.0/23210.72.158.1 to 210.72.159.254210.72.159.255510
81210.72.160.0/23210.72.160.1 to 210.72.161.254210.72.161.255510
82210.72.162.0/23210.72.162.1 to 210.72.163.254210.72.163.255510
83210.72.164.0/23210.72.164.1 to 210.72.165.254210.72.165.255510
84210.72.166.0/23210.72.166.1 to 210.72.167.254210.72.167.255510
85210.72.168.0/23210.72.168.1 to 210.72.169.254210.72.169.255510
86210.72.170.0/23210.72.170.1 to 210.72.171.254210.72.171.255510
87210.72.172.0/23210.72.172.1 to 210.72.173.254210.72.173.255510
88210.72.174.0/23210.72.174.1 to 210.72.175.254210.72.175.255510
89210.72.176.0/23210.72.176.1 to 210.72.177.254210.72.177.255510
90210.72.178.0/23210.72.178.1 to 210.72.179.254210.72.179.255510
91210.72.180.0/23210.72.180.1 to 210.72.181.254210.72.181.255510
92210.72.182.0/23210.72.182.1 to 210.72.183.254210.72.183.255510
93210.72.184.0/23210.72.184.1 to 210.72.185.254210.72.185.255510
94210.72.186.0/23210.72.186.1 to 210.72.187.254210.72.187.255510
95210.72.188.0/23210.72.188.1 to 210.72.189.254210.72.189.255510
96210.72.190.0/23210.72.190.1 to 210.72.191.254210.72.191.255510
97210.72.192.0/23210.72.192.1 to 210.72.193.254210.72.193.255510
98210.72.194.0/23210.72.194.1 to 210.72.195.254210.72.195.255510
99210.72.196.0/23210.72.196.1 to 210.72.197.254210.72.197.255510
100210.72.198.0/23210.72.198.1 to 210.72.199.254210.72.199.255510
101210.72.200.0/23210.72.200.1 to 210.72.201.254210.72.201.255510
102210.72.202.0/23210.72.202.1 to 210.72.203.254210.72.203.255510
103210.72.204.0/23210.72.204.1 to 210.72.205.254210.72.205.255510
104210.72.206.0/23210.72.206.1 to 210.72.207.254210.72.207.255510
105210.72.208.0/23210.72.208.1 to 210.72.209.254210.72.209.255510
106210.72.210.0/23210.72.210.1 to 210.72.211.254210.72.211.255510
107210.72.212.0/23210.72.212.1 to 210.72.213.254210.72.213.255510
108210.72.214.0/23210.72.214.1 to 210.72.215.254210.72.215.255510
109210.72.216.0/23210.72.216.1 to 210.72.217.254210.72.217.255510
110210.72.218.0/23210.72.218.1 to 210.72.219.254210.72.219.255510
111210.72.220.0/23210.72.220.1 to 210.72.221.254210.72.221.255510
112210.72.222.0/23210.72.222.1 to 210.72.223.254210.72.223.255510
113210.72.224.0/23210.72.224.1 to 210.72.225.254210.72.225.255510
114210.72.226.0/23210.72.226.1 to 210.72.227.254210.72.227.255510
115210.72.228.0/23210.72.228.1 to 210.72.229.254210.72.229.255510
116210.72.230.0/23210.72.230.1 to 210.72.231.254210.72.231.255510
117210.72.232.0/23210.72.232.1 to 210.72.233.254210.72.233.255510
118210.72.234.0/23210.72.234.1 to 210.72.235.254210.72.235.255510
119210.72.236.0/23210.72.236.1 to 210.72.237.254210.72.237.255510
120210.72.238.0/23210.72.238.1 to 210.72.239.254210.72.239.255510
121210.72.240.0/23210.72.240.1 to 210.72.241.254210.72.241.255510
122210.72.242.0/23210.72.242.1 to 210.72.243.254210.72.243.255510
123210.72.244.0/23210.72.244.1 to 210.72.245.254210.72.245.255510
124210.72.246.0/23210.72.246.1 to 210.72.247.254210.72.247.255510
125210.72.248.0/23210.72.248.1 to 210.72.249.254210.72.249.255510
126210.72.250.0/23210.72.250.1 to 210.72.251.254210.72.251.255510
127210.72.252.0/23210.72.252.1 to 210.72.253.254210.72.253.255510
128210.72.254.0/23210.72.254.1 to 210.72.255.254210.72.255.255510
129210.73.0.0/23210.73.0.1 to 210.73.1.254210.73.1.255510
130210.73.2.0/23210.73.2.1 to 210.73.3.254210.73.3.255510
131210.73.4.0/23210.73.4.1 to 210.73.5.254210.73.5.255510
132210.73.6.0/23210.73.6.1 to 210.73.7.254210.73.7.255510
133210.73.8.0/23210.73.8.1 to 210.73.9.254210.73.9.255510
134210.73.10.0/23210.73.10.1 to 210.73.11.254210.73.11.255510
135210.73.12.0/23210.73.12.1 to 210.73.13.254210.73.13.255510
136210.73.14.0/23210.73.14.1 to 210.73.15.254210.73.15.255510
137210.73.16.0/23210.73.16.1 to 210.73.17.254210.73.17.255510
138210.73.18.0/23210.73.18.1 to 210.73.19.254210.73.19.255510
139210.73.20.0/23210.73.20.1 to 210.73.21.254210.73.21.255510
140210.73.22.0/23210.73.22.1 to 210.73.23.254210.73.23.255510
141210.73.24.0/23210.73.24.1 to 210.73.25.254210.73.25.255510
142210.73.26.0/23210.73.26.1 to 210.73.27.254210.73.27.255510
143210.73.28.0/23210.73.28.1 to 210.73.29.254210.73.29.255510
144210.73.30.0/23210.73.30.1 to 210.73.31.254210.73.31.255510
145210.73.32.0/23210.73.32.1 to 210.73.33.254210.73.33.255510
146210.73.34.0/23210.73.34.1 to 210.73.35.254210.73.35.255510
147210.73.36.0/23210.73.36.1 to 210.73.37.254210.73.37.255510
148210.73.38.0/23210.73.38.1 to 210.73.39.254210.73.39.255510
149210.73.40.0/23210.73.40.1 to 210.73.41.254210.73.41.255510
150210.73.42.0/23210.73.42.1 to 210.73.43.254210.73.43.255510
151210.73.44.0/23210.73.44.1 to 210.73.45.254210.73.45.255510
152210.73.46.0/23210.73.46.1 to 210.73.47.254210.73.47.255510
153210.73.48.0/23210.73.48.1 to 210.73.49.254210.73.49.255510
154210.73.50.0/23210.73.50.1 to 210.73.51.254210.73.51.255510
155210.73.52.0/23210.73.52.1 to 210.73.53.254210.73.53.255510
156210.73.54.0/23210.73.54.1 to 210.73.55.254210.73.55.255510
157210.73.56.0/23210.73.56.1 to 210.73.57.254210.73.57.255510
158210.73.58.0/23210.73.58.1 to 210.73.59.254210.73.59.255510
159210.73.60.0/23210.73.60.1 to 210.73.61.254210.73.61.255510
160210.73.62.0/23210.73.62.1 to 210.73.63.254210.73.63.255510
161210.73.64.0/23210.73.64.1 to 210.73.65.254210.73.65.255510
162210.73.66.0/23210.73.66.1 to 210.73.67.254210.73.67.255510
163210.73.68.0/23210.73.68.1 to 210.73.69.254210.73.69.255510
164210.73.70.0/23210.73.70.1 to 210.73.71.254210.73.71.255510
165210.73.72.0/23210.73.72.1 to 210.73.73.254210.73.73.255510
166210.73.74.0/23210.73.74.1 to 210.73.75.254210.73.75.255510
167210.73.76.0/23210.73.76.1 to 210.73.77.254210.73.77.255510
168210.73.78.0/23210.73.78.1 to 210.73.79.254210.73.79.255510
169210.73.80.0/23210.73.80.1 to 210.73.81.254210.73.81.255510
170210.73.82.0/23210.73.82.1 to 210.73.83.254210.73.83.255510
171210.73.84.0/23210.73.84.1 to 210.73.85.254210.73.85.255510
172210.73.86.0/23210.73.86.1 to 210.73.87.254210.73.87.255510
173210.73.88.0/23210.73.88.1 to 210.73.89.254210.73.89.255510
174210.73.90.0/23210.73.90.1 to 210.73.91.254210.73.91.255510
175210.73.92.0/23210.73.92.1 to 210.73.93.254210.73.93.255510
176210.73.94.0/23210.73.94.1 to 210.73.95.254210.73.95.255510
177210.73.96.0/23210.73.96.1 to 210.73.97.254210.73.97.255510
178210.73.98.0/23210.73.98.1 to 210.73.99.254210.73.99.255510
179210.73.100.0/23210.73.100.1 to 210.73.101.254210.73.101.255510
180210.73.102.0/23210.73.102.1 to 210.73.103.254210.73.103.255510
181210.73.104.0/23210.73.104.1 to 210.73.105.254210.73.105.255510
182210.73.106.0/23210.73.106.1 to 210.73.107.254210.73.107.255510
183210.73.108.0/23210.73.108.1 to 210.73.109.254210.73.109.255510
184210.73.110.0/23210.73.110.1 to 210.73.111.254210.73.111.255510
185210.73.112.0/23210.73.112.1 to 210.73.113.254210.73.113.255510
186210.73.114.0/23210.73.114.1 to 210.73.115.254210.73.115.255510
187210.73.116.0/23210.73.116.1 to 210.73.117.254210.73.117.255510
188210.73.118.0/23210.73.118.1 to 210.73.119.254210.73.119.255510
189210.73.120.0/23210.73.120.1 to 210.73.121.254210.73.121.255510
190210.73.122.0/23210.73.122.1 to 210.73.123.254210.73.123.255510
191210.73.124.0/23210.73.124.1 to 210.73.125.254210.73.125.255510
192210.73.126.0/23210.73.126.1 to 210.73.127.254210.73.127.255510
193210.73.128.0/23210.73.128.1 to 210.73.129.254210.73.129.255510
194210.73.130.0/23210.73.130.1 to 210.73.131.254210.73.131.255510
195210.73.132.0/23210.73.132.1 to 210.73.133.254210.73.133.255510
196210.73.134.0/23210.73.134.1 to 210.73.135.254210.73.135.255510
197210.73.136.0/23210.73.136.1 to 210.73.137.254210.73.137.255510
198210.73.138.0/23210.73.138.1 to 210.73.139.254210.73.139.255510
199210.73.140.0/23210.73.140.1 to 210.73.141.254210.73.141.255510
200210.73.142.0/23210.73.142.1 to 210.73.143.254210.73.143.255510
201210.73.144.0/23210.73.144.1 to 210.73.145.254210.73.145.255510
202210.73.146.0/23210.73.146.1 to 210.73.147.254210.73.147.255510
203210.73.148.0/23210.73.148.1 to 210.73.149.254210.73.149.255510
204210.73.150.0/23210.73.150.1 to 210.73.151.254210.73.151.255510
205210.73.152.0/23210.73.152.1 to 210.73.153.254210.73.153.255510
206210.73.154.0/23210.73.154.1 to 210.73.155.254210.73.155.255510
207210.73.156.0/23210.73.156.1 to 210.73.157.254210.73.157.255510
208210.73.158.0/23210.73.158.1 to 210.73.159.254210.73.159.255510
209210.73.160.0/23210.73.160.1 to 210.73.161.254210.73.161.255510
210210.73.162.0/23210.73.162.1 to 210.73.163.254210.73.163.255510
211210.73.164.0/23210.73.164.1 to 210.73.165.254210.73.165.255510
212210.73.166.0/23210.73.166.1 to 210.73.167.254210.73.167.255510
213210.73.168.0/23210.73.168.1 to 210.73.169.254210.73.169.255510
214210.73.170.0/23210.73.170.1 to 210.73.171.254210.73.171.255510
215210.73.172.0/23210.73.172.1 to 210.73.173.254210.73.173.255510
216210.73.174.0/23210.73.174.1 to 210.73.175.254210.73.175.255510
217210.73.176.0/23210.73.176.1 to 210.73.177.254210.73.177.255510
218210.73.178.0/23210.73.178.1 to 210.73.179.254210.73.179.255510
219210.73.180.0/23210.73.180.1 to 210.73.181.254210.73.181.255510
220210.73.182.0/23210.73.182.1 to 210.73.183.254210.73.183.255510
221210.73.184.0/23210.73.184.1 to 210.73.185.254210.73.185.255510
222210.73.186.0/23210.73.186.1 to 210.73.187.254210.73.187.255510
223210.73.188.0/23210.73.188.1 to 210.73.189.254210.73.189.255510
224210.73.190.0/23210.73.190.1 to 210.73.191.254210.73.191.255510
225210.73.192.0/23210.73.192.1 to 210.73.193.254210.73.193.255510
226210.73.194.0/23210.73.194.1 to 210.73.195.254210.73.195.255510
227210.73.196.0/23210.73.196.1 to 210.73.197.254210.73.197.255510
228210.73.198.0/23210.73.198.1 to 210.73.199.254210.73.199.255510
229210.73.200.0/23210.73.200.1 to 210.73.201.254210.73.201.255510
230210.73.202.0/23210.73.202.1 to 210.73.203.254210.73.203.255510
231210.73.204.0/23210.73.204.1 to 210.73.205.254210.73.205.255510
232210.73.206.0/23210.73.206.1 to 210.73.207.254210.73.207.255510
233210.73.208.0/23210.73.208.1 to 210.73.209.254210.73.209.255510
234210.73.210.0/23210.73.210.1 to 210.73.211.254210.73.211.255510
235210.73.212.0/23210.73.212.1 to 210.73.213.254210.73.213.255510
236210.73.214.0/23210.73.214.1 to 210.73.215.254210.73.215.255510
237210.73.216.0/23210.73.216.1 to 210.73.217.254210.73.217.255510
238210.73.218.0/23210.73.218.1 to 210.73.219.254210.73.219.255510
239210.73.220.0/23210.73.220.1 to 210.73.221.254210.73.221.255510
240210.73.222.0/23210.73.222.1 to 210.73.223.254210.73.223.255510
241210.73.224.0/23210.73.224.1 to 210.73.225.254210.73.225.255510
242210.73.226.0/23210.73.226.1 to 210.73.227.254210.73.227.255510
243210.73.228.0/23210.73.228.1 to 210.73.229.254210.73.229.255510
244210.73.230.0/23210.73.230.1 to 210.73.231.254210.73.231.255510
245210.73.232.0/23210.73.232.1 to 210.73.233.254210.73.233.255510
246210.73.234.0/23210.73.234.1 to 210.73.235.254210.73.235.255510
247210.73.236.0/23210.73.236.1 to 210.73.237.254210.73.237.255510
248210.73.238.0/23210.73.238.1 to 210.73.239.254210.73.239.255510
249210.73.240.0/23210.73.240.1 to 210.73.241.254210.73.241.255510
250210.73.242.0/23210.73.242.1 to 210.73.243.254210.73.243.255510
251210.73.244.0/23210.73.244.1 to 210.73.245.254210.73.245.255510
252210.73.246.0/23210.73.246.1 to 210.73.247.254210.73.247.255510
253210.73.248.0/23210.73.248.1 to 210.73.249.254210.73.249.255510
254210.73.250.0/23210.73.250.1 to 210.73.251.254210.73.251.255510
255210.73.252.0/23210.73.252.1 to 210.73.253.254210.73.253.255510
256210.73.254.0/23210.73.254.1 to 210.73.255.254210.73.255.255510

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.