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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.

Network26.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
26.0.0.0
Broadcast address
27.255.255.255
First usable
26.0.0.1
Last usable
27.255.255.254
Usable hosts
33,554,430 (33,554,432 less the network and broadcast addresses)
Subnet mask
254.0.0.0
Wildcard mask
1.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/7
Type
Public public
Old class
A (default /8)
As numbers
Hex 1A000000 · Integer 436207616 to 469762047
Reverse DNS zones
26.in-addr.arpa
27.in-addr.arpa
/7 is not on a 8-bit boundary, so it takes 2 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00011010.00000000.00000000.0000000026.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network00011010.00000000.00000000.0000000026.0.0.0
Broadcast00011011.11111111.11111111.1111111127.255.255.255
Split into smaller subnets/15
/8 (2)/9 (4)/10 (8)/11 (16)/12 (32)/13 (64)/14 (128)/15 (256)/16 (512)/17 (1,024)/18 (2,048)/19 (4,096)

26.0.0.0/7 makes 256 subnets of /15.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
126.0.0.0/1526.0.0.1 to 26.1.255.25426.1.255.255131,070
226.2.0.0/1526.2.0.1 to 26.3.255.25426.3.255.255131,070
326.4.0.0/1526.4.0.1 to 26.5.255.25426.5.255.255131,070
426.6.0.0/1526.6.0.1 to 26.7.255.25426.7.255.255131,070
526.8.0.0/1526.8.0.1 to 26.9.255.25426.9.255.255131,070
626.10.0.0/1526.10.0.1 to 26.11.255.25426.11.255.255131,070
726.12.0.0/1526.12.0.1 to 26.13.255.25426.13.255.255131,070
826.14.0.0/1526.14.0.1 to 26.15.255.25426.15.255.255131,070
926.16.0.0/1526.16.0.1 to 26.17.255.25426.17.255.255131,070
1026.18.0.0/1526.18.0.1 to 26.19.255.25426.19.255.255131,070
1126.20.0.0/1526.20.0.1 to 26.21.255.25426.21.255.255131,070
1226.22.0.0/1526.22.0.1 to 26.23.255.25426.23.255.255131,070
1326.24.0.0/1526.24.0.1 to 26.25.255.25426.25.255.255131,070
1426.26.0.0/1526.26.0.1 to 26.27.255.25426.27.255.255131,070
1526.28.0.0/1526.28.0.1 to 26.29.255.25426.29.255.255131,070
1626.30.0.0/1526.30.0.1 to 26.31.255.25426.31.255.255131,070
1726.32.0.0/1526.32.0.1 to 26.33.255.25426.33.255.255131,070
1826.34.0.0/1526.34.0.1 to 26.35.255.25426.35.255.255131,070
1926.36.0.0/1526.36.0.1 to 26.37.255.25426.37.255.255131,070
2026.38.0.0/1526.38.0.1 to 26.39.255.25426.39.255.255131,070
2126.40.0.0/1526.40.0.1 to 26.41.255.25426.41.255.255131,070
2226.42.0.0/1526.42.0.1 to 26.43.255.25426.43.255.255131,070
2326.44.0.0/1526.44.0.1 to 26.45.255.25426.45.255.255131,070
2426.46.0.0/1526.46.0.1 to 26.47.255.25426.47.255.255131,070
2526.48.0.0/1526.48.0.1 to 26.49.255.25426.49.255.255131,070
2626.50.0.0/1526.50.0.1 to 26.51.255.25426.51.255.255131,070
2726.52.0.0/1526.52.0.1 to 26.53.255.25426.53.255.255131,070
2826.54.0.0/1526.54.0.1 to 26.55.255.25426.55.255.255131,070
2926.56.0.0/1526.56.0.1 to 26.57.255.25426.57.255.255131,070
3026.58.0.0/1526.58.0.1 to 26.59.255.25426.59.255.255131,070
3126.60.0.0/1526.60.0.1 to 26.61.255.25426.61.255.255131,070
3226.62.0.0/1526.62.0.1 to 26.63.255.25426.63.255.255131,070
3326.64.0.0/1526.64.0.1 to 26.65.255.25426.65.255.255131,070
3426.66.0.0/1526.66.0.1 to 26.67.255.25426.67.255.255131,070
3526.68.0.0/1526.68.0.1 to 26.69.255.25426.69.255.255131,070
3626.70.0.0/1526.70.0.1 to 26.71.255.25426.71.255.255131,070
3726.72.0.0/1526.72.0.1 to 26.73.255.25426.73.255.255131,070
3826.74.0.0/1526.74.0.1 to 26.75.255.25426.75.255.255131,070
3926.76.0.0/1526.76.0.1 to 26.77.255.25426.77.255.255131,070
4026.78.0.0/1526.78.0.1 to 26.79.255.25426.79.255.255131,070
4126.80.0.0/1526.80.0.1 to 26.81.255.25426.81.255.255131,070
4226.82.0.0/1526.82.0.1 to 26.83.255.25426.83.255.255131,070
4326.84.0.0/1526.84.0.1 to 26.85.255.25426.85.255.255131,070
4426.86.0.0/1526.86.0.1 to 26.87.255.25426.87.255.255131,070
4526.88.0.0/1526.88.0.1 to 26.89.255.25426.89.255.255131,070
4626.90.0.0/1526.90.0.1 to 26.91.255.25426.91.255.255131,070
4726.92.0.0/1526.92.0.1 to 26.93.255.25426.93.255.255131,070
4826.94.0.0/1526.94.0.1 to 26.95.255.25426.95.255.255131,070
4926.96.0.0/1526.96.0.1 to 26.97.255.25426.97.255.255131,070
5026.98.0.0/1526.98.0.1 to 26.99.255.25426.99.255.255131,070
5126.100.0.0/1526.100.0.1 to 26.101.255.25426.101.255.255131,070
5226.102.0.0/1526.102.0.1 to 26.103.255.25426.103.255.255131,070
5326.104.0.0/1526.104.0.1 to 26.105.255.25426.105.255.255131,070
5426.106.0.0/1526.106.0.1 to 26.107.255.25426.107.255.255131,070
5526.108.0.0/1526.108.0.1 to 26.109.255.25426.109.255.255131,070
5626.110.0.0/1526.110.0.1 to 26.111.255.25426.111.255.255131,070
5726.112.0.0/1526.112.0.1 to 26.113.255.25426.113.255.255131,070
5826.114.0.0/1526.114.0.1 to 26.115.255.25426.115.255.255131,070
5926.116.0.0/1526.116.0.1 to 26.117.255.25426.117.255.255131,070
6026.118.0.0/1526.118.0.1 to 26.119.255.25426.119.255.255131,070
6126.120.0.0/1526.120.0.1 to 26.121.255.25426.121.255.255131,070
6226.122.0.0/1526.122.0.1 to 26.123.255.25426.123.255.255131,070
6326.124.0.0/1526.124.0.1 to 26.125.255.25426.125.255.255131,070
6426.126.0.0/1526.126.0.1 to 26.127.255.25426.127.255.255131,070
6526.128.0.0/1526.128.0.1 to 26.129.255.25426.129.255.255131,070
6626.130.0.0/1526.130.0.1 to 26.131.255.25426.131.255.255131,070
6726.132.0.0/1526.132.0.1 to 26.133.255.25426.133.255.255131,070
6826.134.0.0/1526.134.0.1 to 26.135.255.25426.135.255.255131,070
6926.136.0.0/1526.136.0.1 to 26.137.255.25426.137.255.255131,070
7026.138.0.0/1526.138.0.1 to 26.139.255.25426.139.255.255131,070
7126.140.0.0/1526.140.0.1 to 26.141.255.25426.141.255.255131,070
7226.142.0.0/1526.142.0.1 to 26.143.255.25426.143.255.255131,070
7326.144.0.0/1526.144.0.1 to 26.145.255.25426.145.255.255131,070
7426.146.0.0/1526.146.0.1 to 26.147.255.25426.147.255.255131,070
7526.148.0.0/1526.148.0.1 to 26.149.255.25426.149.255.255131,070
7626.150.0.0/1526.150.0.1 to 26.151.255.25426.151.255.255131,070
7726.152.0.0/1526.152.0.1 to 26.153.255.25426.153.255.255131,070
7826.154.0.0/1526.154.0.1 to 26.155.255.25426.155.255.255131,070
7926.156.0.0/1526.156.0.1 to 26.157.255.25426.157.255.255131,070
8026.158.0.0/1526.158.0.1 to 26.159.255.25426.159.255.255131,070
8126.160.0.0/1526.160.0.1 to 26.161.255.25426.161.255.255131,070
8226.162.0.0/1526.162.0.1 to 26.163.255.25426.163.255.255131,070
8326.164.0.0/1526.164.0.1 to 26.165.255.25426.165.255.255131,070
8426.166.0.0/1526.166.0.1 to 26.167.255.25426.167.255.255131,070
8526.168.0.0/1526.168.0.1 to 26.169.255.25426.169.255.255131,070
8626.170.0.0/1526.170.0.1 to 26.171.255.25426.171.255.255131,070
8726.172.0.0/1526.172.0.1 to 26.173.255.25426.173.255.255131,070
8826.174.0.0/1526.174.0.1 to 26.175.255.25426.175.255.255131,070
8926.176.0.0/1526.176.0.1 to 26.177.255.25426.177.255.255131,070
9026.178.0.0/1526.178.0.1 to 26.179.255.25426.179.255.255131,070
9126.180.0.0/1526.180.0.1 to 26.181.255.25426.181.255.255131,070
9226.182.0.0/1526.182.0.1 to 26.183.255.25426.183.255.255131,070
9326.184.0.0/1526.184.0.1 to 26.185.255.25426.185.255.255131,070
9426.186.0.0/1526.186.0.1 to 26.187.255.25426.187.255.255131,070
9526.188.0.0/1526.188.0.1 to 26.189.255.25426.189.255.255131,070
9626.190.0.0/1526.190.0.1 to 26.191.255.25426.191.255.255131,070
9726.192.0.0/1526.192.0.1 to 26.193.255.25426.193.255.255131,070
9826.194.0.0/1526.194.0.1 to 26.195.255.25426.195.255.255131,070
9926.196.0.0/1526.196.0.1 to 26.197.255.25426.197.255.255131,070
10026.198.0.0/1526.198.0.1 to 26.199.255.25426.199.255.255131,070
10126.200.0.0/1526.200.0.1 to 26.201.255.25426.201.255.255131,070
10226.202.0.0/1526.202.0.1 to 26.203.255.25426.203.255.255131,070
10326.204.0.0/1526.204.0.1 to 26.205.255.25426.205.255.255131,070
10426.206.0.0/1526.206.0.1 to 26.207.255.25426.207.255.255131,070
10526.208.0.0/1526.208.0.1 to 26.209.255.25426.209.255.255131,070
10626.210.0.0/1526.210.0.1 to 26.211.255.25426.211.255.255131,070
10726.212.0.0/1526.212.0.1 to 26.213.255.25426.213.255.255131,070
10826.214.0.0/1526.214.0.1 to 26.215.255.25426.215.255.255131,070
10926.216.0.0/1526.216.0.1 to 26.217.255.25426.217.255.255131,070
11026.218.0.0/1526.218.0.1 to 26.219.255.25426.219.255.255131,070
11126.220.0.0/1526.220.0.1 to 26.221.255.25426.221.255.255131,070
11226.222.0.0/1526.222.0.1 to 26.223.255.25426.223.255.255131,070
11326.224.0.0/1526.224.0.1 to 26.225.255.25426.225.255.255131,070
11426.226.0.0/1526.226.0.1 to 26.227.255.25426.227.255.255131,070
11526.228.0.0/1526.228.0.1 to 26.229.255.25426.229.255.255131,070
11626.230.0.0/1526.230.0.1 to 26.231.255.25426.231.255.255131,070
11726.232.0.0/1526.232.0.1 to 26.233.255.25426.233.255.255131,070
11826.234.0.0/1526.234.0.1 to 26.235.255.25426.235.255.255131,070
11926.236.0.0/1526.236.0.1 to 26.237.255.25426.237.255.255131,070
12026.238.0.0/1526.238.0.1 to 26.239.255.25426.239.255.255131,070
12126.240.0.0/1526.240.0.1 to 26.241.255.25426.241.255.255131,070
12226.242.0.0/1526.242.0.1 to 26.243.255.25426.243.255.255131,070
12326.244.0.0/1526.244.0.1 to 26.245.255.25426.245.255.255131,070
12426.246.0.0/1526.246.0.1 to 26.247.255.25426.247.255.255131,070
12526.248.0.0/1526.248.0.1 to 26.249.255.25426.249.255.255131,070
12626.250.0.0/1526.250.0.1 to 26.251.255.25426.251.255.255131,070
12726.252.0.0/1526.252.0.1 to 26.253.255.25426.253.255.255131,070
12826.254.0.0/1526.254.0.1 to 26.255.255.25426.255.255.255131,070
12927.0.0.0/1527.0.0.1 to 27.1.255.25427.1.255.255131,070
13027.2.0.0/1527.2.0.1 to 27.3.255.25427.3.255.255131,070
13127.4.0.0/1527.4.0.1 to 27.5.255.25427.5.255.255131,070
13227.6.0.0/1527.6.0.1 to 27.7.255.25427.7.255.255131,070
13327.8.0.0/1527.8.0.1 to 27.9.255.25427.9.255.255131,070
13427.10.0.0/1527.10.0.1 to 27.11.255.25427.11.255.255131,070
13527.12.0.0/1527.12.0.1 to 27.13.255.25427.13.255.255131,070
13627.14.0.0/1527.14.0.1 to 27.15.255.25427.15.255.255131,070
13727.16.0.0/1527.16.0.1 to 27.17.255.25427.17.255.255131,070
13827.18.0.0/1527.18.0.1 to 27.19.255.25427.19.255.255131,070
13927.20.0.0/1527.20.0.1 to 27.21.255.25427.21.255.255131,070
14027.22.0.0/1527.22.0.1 to 27.23.255.25427.23.255.255131,070
14127.24.0.0/1527.24.0.1 to 27.25.255.25427.25.255.255131,070
14227.26.0.0/1527.26.0.1 to 27.27.255.25427.27.255.255131,070
14327.28.0.0/1527.28.0.1 to 27.29.255.25427.29.255.255131,070
14427.30.0.0/1527.30.0.1 to 27.31.255.25427.31.255.255131,070
14527.32.0.0/1527.32.0.1 to 27.33.255.25427.33.255.255131,070
14627.34.0.0/1527.34.0.1 to 27.35.255.25427.35.255.255131,070
14727.36.0.0/1527.36.0.1 to 27.37.255.25427.37.255.255131,070
14827.38.0.0/1527.38.0.1 to 27.39.255.25427.39.255.255131,070
14927.40.0.0/1527.40.0.1 to 27.41.255.25427.41.255.255131,070
15027.42.0.0/1527.42.0.1 to 27.43.255.25427.43.255.255131,070
15127.44.0.0/1527.44.0.1 to 27.45.255.25427.45.255.255131,070
15227.46.0.0/1527.46.0.1 to 27.47.255.25427.47.255.255131,070
15327.48.0.0/1527.48.0.1 to 27.49.255.25427.49.255.255131,070
15427.50.0.0/1527.50.0.1 to 27.51.255.25427.51.255.255131,070
15527.52.0.0/1527.52.0.1 to 27.53.255.25427.53.255.255131,070
15627.54.0.0/1527.54.0.1 to 27.55.255.25427.55.255.255131,070
15727.56.0.0/1527.56.0.1 to 27.57.255.25427.57.255.255131,070
15827.58.0.0/1527.58.0.1 to 27.59.255.25427.59.255.255131,070
15927.60.0.0/1527.60.0.1 to 27.61.255.25427.61.255.255131,070
16027.62.0.0/1527.62.0.1 to 27.63.255.25427.63.255.255131,070
16127.64.0.0/1527.64.0.1 to 27.65.255.25427.65.255.255131,070
16227.66.0.0/1527.66.0.1 to 27.67.255.25427.67.255.255131,070
16327.68.0.0/1527.68.0.1 to 27.69.255.25427.69.255.255131,070
16427.70.0.0/1527.70.0.1 to 27.71.255.25427.71.255.255131,070
16527.72.0.0/1527.72.0.1 to 27.73.255.25427.73.255.255131,070
16627.74.0.0/1527.74.0.1 to 27.75.255.25427.75.255.255131,070
16727.76.0.0/1527.76.0.1 to 27.77.255.25427.77.255.255131,070
16827.78.0.0/1527.78.0.1 to 27.79.255.25427.79.255.255131,070
16927.80.0.0/1527.80.0.1 to 27.81.255.25427.81.255.255131,070
17027.82.0.0/1527.82.0.1 to 27.83.255.25427.83.255.255131,070
17127.84.0.0/1527.84.0.1 to 27.85.255.25427.85.255.255131,070
17227.86.0.0/1527.86.0.1 to 27.87.255.25427.87.255.255131,070
17327.88.0.0/1527.88.0.1 to 27.89.255.25427.89.255.255131,070
17427.90.0.0/1527.90.0.1 to 27.91.255.25427.91.255.255131,070
17527.92.0.0/1527.92.0.1 to 27.93.255.25427.93.255.255131,070
17627.94.0.0/1527.94.0.1 to 27.95.255.25427.95.255.255131,070
17727.96.0.0/1527.96.0.1 to 27.97.255.25427.97.255.255131,070
17827.98.0.0/1527.98.0.1 to 27.99.255.25427.99.255.255131,070
17927.100.0.0/1527.100.0.1 to 27.101.255.25427.101.255.255131,070
18027.102.0.0/1527.102.0.1 to 27.103.255.25427.103.255.255131,070
18127.104.0.0/1527.104.0.1 to 27.105.255.25427.105.255.255131,070
18227.106.0.0/1527.106.0.1 to 27.107.255.25427.107.255.255131,070
18327.108.0.0/1527.108.0.1 to 27.109.255.25427.109.255.255131,070
18427.110.0.0/1527.110.0.1 to 27.111.255.25427.111.255.255131,070
18527.112.0.0/1527.112.0.1 to 27.113.255.25427.113.255.255131,070
18627.114.0.0/1527.114.0.1 to 27.115.255.25427.115.255.255131,070
18727.116.0.0/1527.116.0.1 to 27.117.255.25427.117.255.255131,070
18827.118.0.0/1527.118.0.1 to 27.119.255.25427.119.255.255131,070
18927.120.0.0/1527.120.0.1 to 27.121.255.25427.121.255.255131,070
19027.122.0.0/1527.122.0.1 to 27.123.255.25427.123.255.255131,070
19127.124.0.0/1527.124.0.1 to 27.125.255.25427.125.255.255131,070
19227.126.0.0/1527.126.0.1 to 27.127.255.25427.127.255.255131,070
19327.128.0.0/1527.128.0.1 to 27.129.255.25427.129.255.255131,070
19427.130.0.0/1527.130.0.1 to 27.131.255.25427.131.255.255131,070
19527.132.0.0/1527.132.0.1 to 27.133.255.25427.133.255.255131,070
19627.134.0.0/1527.134.0.1 to 27.135.255.25427.135.255.255131,070
19727.136.0.0/1527.136.0.1 to 27.137.255.25427.137.255.255131,070
19827.138.0.0/1527.138.0.1 to 27.139.255.25427.139.255.255131,070
19927.140.0.0/1527.140.0.1 to 27.141.255.25427.141.255.255131,070
20027.142.0.0/1527.142.0.1 to 27.143.255.25427.143.255.255131,070
20127.144.0.0/1527.144.0.1 to 27.145.255.25427.145.255.255131,070
20227.146.0.0/1527.146.0.1 to 27.147.255.25427.147.255.255131,070
20327.148.0.0/1527.148.0.1 to 27.149.255.25427.149.255.255131,070
20427.150.0.0/1527.150.0.1 to 27.151.255.25427.151.255.255131,070
20527.152.0.0/1527.152.0.1 to 27.153.255.25427.153.255.255131,070
20627.154.0.0/1527.154.0.1 to 27.155.255.25427.155.255.255131,070
20727.156.0.0/1527.156.0.1 to 27.157.255.25427.157.255.255131,070
20827.158.0.0/1527.158.0.1 to 27.159.255.25427.159.255.255131,070
20927.160.0.0/1527.160.0.1 to 27.161.255.25427.161.255.255131,070
21027.162.0.0/1527.162.0.1 to 27.163.255.25427.163.255.255131,070
21127.164.0.0/1527.164.0.1 to 27.165.255.25427.165.255.255131,070
21227.166.0.0/1527.166.0.1 to 27.167.255.25427.167.255.255131,070
21327.168.0.0/1527.168.0.1 to 27.169.255.25427.169.255.255131,070
21427.170.0.0/1527.170.0.1 to 27.171.255.25427.171.255.255131,070
21527.172.0.0/1527.172.0.1 to 27.173.255.25427.173.255.255131,070
21627.174.0.0/1527.174.0.1 to 27.175.255.25427.175.255.255131,070
21727.176.0.0/1527.176.0.1 to 27.177.255.25427.177.255.255131,070
21827.178.0.0/1527.178.0.1 to 27.179.255.25427.179.255.255131,070
21927.180.0.0/1527.180.0.1 to 27.181.255.25427.181.255.255131,070
22027.182.0.0/1527.182.0.1 to 27.183.255.25427.183.255.255131,070
22127.184.0.0/1527.184.0.1 to 27.185.255.25427.185.255.255131,070
22227.186.0.0/1527.186.0.1 to 27.187.255.25427.187.255.255131,070
22327.188.0.0/1527.188.0.1 to 27.189.255.25427.189.255.255131,070
22427.190.0.0/1527.190.0.1 to 27.191.255.25427.191.255.255131,070
22527.192.0.0/1527.192.0.1 to 27.193.255.25427.193.255.255131,070
22627.194.0.0/1527.194.0.1 to 27.195.255.25427.195.255.255131,070
22727.196.0.0/1527.196.0.1 to 27.197.255.25427.197.255.255131,070
22827.198.0.0/1527.198.0.1 to 27.199.255.25427.199.255.255131,070
22927.200.0.0/1527.200.0.1 to 27.201.255.25427.201.255.255131,070
23027.202.0.0/1527.202.0.1 to 27.203.255.25427.203.255.255131,070
23127.204.0.0/1527.204.0.1 to 27.205.255.25427.205.255.255131,070
23227.206.0.0/1527.206.0.1 to 27.207.255.25427.207.255.255131,070
23327.208.0.0/1527.208.0.1 to 27.209.255.25427.209.255.255131,070
23427.210.0.0/1527.210.0.1 to 27.211.255.25427.211.255.255131,070
23527.212.0.0/1527.212.0.1 to 27.213.255.25427.213.255.255131,070
23627.214.0.0/1527.214.0.1 to 27.215.255.25427.215.255.255131,070
23727.216.0.0/1527.216.0.1 to 27.217.255.25427.217.255.255131,070
23827.218.0.0/1527.218.0.1 to 27.219.255.25427.219.255.255131,070
23927.220.0.0/1527.220.0.1 to 27.221.255.25427.221.255.255131,070
24027.222.0.0/1527.222.0.1 to 27.223.255.25427.223.255.255131,070
24127.224.0.0/1527.224.0.1 to 27.225.255.25427.225.255.255131,070
24227.226.0.0/1527.226.0.1 to 27.227.255.25427.227.255.255131,070
24327.228.0.0/1527.228.0.1 to 27.229.255.25427.229.255.255131,070
24427.230.0.0/1527.230.0.1 to 27.231.255.25427.231.255.255131,070
24527.232.0.0/1527.232.0.1 to 27.233.255.25427.233.255.255131,070
24627.234.0.0/1527.234.0.1 to 27.235.255.25427.235.255.255131,070
24727.236.0.0/1527.236.0.1 to 27.237.255.25427.237.255.255131,070
24827.238.0.0/1527.238.0.1 to 27.239.255.25427.239.255.255131,070
24927.240.0.0/1527.240.0.1 to 27.241.255.25427.241.255.255131,070
25027.242.0.0/1527.242.0.1 to 27.243.255.25427.243.255.255131,070
25127.244.0.0/1527.244.0.1 to 27.245.255.25427.245.255.255131,070
25227.246.0.0/1527.246.0.1 to 27.247.255.25427.247.255.255131,070
25327.248.0.0/1527.248.0.1 to 27.249.255.25427.249.255.255131,070
25427.250.0.0/1527.250.0.1 to 27.251.255.25427.251.255.255131,070
25527.252.0.0/1527.252.0.1 to 27.253.255.25427.253.255.255131,070
25627.254.0.0/1527.254.0.1 to 27.255.255.25427.255.255.255131,070

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.