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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.

Network26.0.0.0/9
Usable hosts8,388,606
Subnet mask255.128.0.0
Addresses8,388,608
Network address
26.0.0.0
Broadcast address
26.127.255.255
First usable
26.0.0.1
Last usable
26.127.255.254
Usable hosts
8,388,606 (8,388,608 less the network and broadcast addresses)
Subnet mask
255.128.0.0
Wildcard mask
0.127.255.255 (Cisco ACLs, OSPF)
Prefix length
/9
Type
Public public
Old class
A (default /8)
As numbers
Hex 1A000000 · Integer 436207616 to 444596223
Reverse DNS zones
0.26.in-addr.arpa
1.26.in-addr.arpa
2.26.in-addr.arpa
3.26.in-addr.arpa
4.26.in-addr.arpa
5.26.in-addr.arpa
6.26.in-addr.arpa
7.26.in-addr.arpa
8.26.in-addr.arpa
9.26.in-addr.arpa
10.26.in-addr.arpa
11.26.in-addr.arpa
12.26.in-addr.arpa
13.26.in-addr.arpa
14.26.in-addr.arpa
15.26.in-addr.arpa
and 112 more
/9 is not on a 8-bit boundary, so it takes 128 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00011010.00000000.00000000.0000000026.0.0.0
Subnet mask11111111.10000000.00000000.00000000255.128.0.0
Network00011010.00000000.00000000.0000000026.0.0.0
Broadcast00011010.01111111.11111111.1111111126.127.255.255
Split into smaller subnets/21
/10 (2)/11 (4)/12 (8)/13 (16)/14 (32)/15 (64)/16 (128)/17 (256)/18 (512)/19 (1,024)/20 (2,048)/21 (4,096)

26.0.0.0/9 makes 4,096 subnets of /21; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
126.0.0.0/2126.0.0.1 to 26.0.7.25426.0.7.2552,046
226.0.8.0/2126.0.8.1 to 26.0.15.25426.0.15.2552,046
326.0.16.0/2126.0.16.1 to 26.0.23.25426.0.23.2552,046
426.0.24.0/2126.0.24.1 to 26.0.31.25426.0.31.2552,046
526.0.32.0/2126.0.32.1 to 26.0.39.25426.0.39.2552,046
626.0.40.0/2126.0.40.1 to 26.0.47.25426.0.47.2552,046
726.0.48.0/2126.0.48.1 to 26.0.55.25426.0.55.2552,046
826.0.56.0/2126.0.56.1 to 26.0.63.25426.0.63.2552,046
926.0.64.0/2126.0.64.1 to 26.0.71.25426.0.71.2552,046
1026.0.72.0/2126.0.72.1 to 26.0.79.25426.0.79.2552,046
1126.0.80.0/2126.0.80.1 to 26.0.87.25426.0.87.2552,046
1226.0.88.0/2126.0.88.1 to 26.0.95.25426.0.95.2552,046
1326.0.96.0/2126.0.96.1 to 26.0.103.25426.0.103.2552,046
1426.0.104.0/2126.0.104.1 to 26.0.111.25426.0.111.2552,046
1526.0.112.0/2126.0.112.1 to 26.0.119.25426.0.119.2552,046
1626.0.120.0/2126.0.120.1 to 26.0.127.25426.0.127.2552,046
1726.0.128.0/2126.0.128.1 to 26.0.135.25426.0.135.2552,046
1826.0.136.0/2126.0.136.1 to 26.0.143.25426.0.143.2552,046
1926.0.144.0/2126.0.144.1 to 26.0.151.25426.0.151.2552,046
2026.0.152.0/2126.0.152.1 to 26.0.159.25426.0.159.2552,046
2126.0.160.0/2126.0.160.1 to 26.0.167.25426.0.167.2552,046
2226.0.168.0/2126.0.168.1 to 26.0.175.25426.0.175.2552,046
2326.0.176.0/2126.0.176.1 to 26.0.183.25426.0.183.2552,046
2426.0.184.0/2126.0.184.1 to 26.0.191.25426.0.191.2552,046
2526.0.192.0/2126.0.192.1 to 26.0.199.25426.0.199.2552,046
2626.0.200.0/2126.0.200.1 to 26.0.207.25426.0.207.2552,046
2726.0.208.0/2126.0.208.1 to 26.0.215.25426.0.215.2552,046
2826.0.216.0/2126.0.216.1 to 26.0.223.25426.0.223.2552,046
2926.0.224.0/2126.0.224.1 to 26.0.231.25426.0.231.2552,046
3026.0.232.0/2126.0.232.1 to 26.0.239.25426.0.239.2552,046
3126.0.240.0/2126.0.240.1 to 26.0.247.25426.0.247.2552,046
3226.0.248.0/2126.0.248.1 to 26.0.255.25426.0.255.2552,046
3326.1.0.0/2126.1.0.1 to 26.1.7.25426.1.7.2552,046
3426.1.8.0/2126.1.8.1 to 26.1.15.25426.1.15.2552,046
3526.1.16.0/2126.1.16.1 to 26.1.23.25426.1.23.2552,046
3626.1.24.0/2126.1.24.1 to 26.1.31.25426.1.31.2552,046
3726.1.32.0/2126.1.32.1 to 26.1.39.25426.1.39.2552,046
3826.1.40.0/2126.1.40.1 to 26.1.47.25426.1.47.2552,046
3926.1.48.0/2126.1.48.1 to 26.1.55.25426.1.55.2552,046
4026.1.56.0/2126.1.56.1 to 26.1.63.25426.1.63.2552,046
4126.1.64.0/2126.1.64.1 to 26.1.71.25426.1.71.2552,046
4226.1.72.0/2126.1.72.1 to 26.1.79.25426.1.79.2552,046
4326.1.80.0/2126.1.80.1 to 26.1.87.25426.1.87.2552,046
4426.1.88.0/2126.1.88.1 to 26.1.95.25426.1.95.2552,046
4526.1.96.0/2126.1.96.1 to 26.1.103.25426.1.103.2552,046
4626.1.104.0/2126.1.104.1 to 26.1.111.25426.1.111.2552,046
4726.1.112.0/2126.1.112.1 to 26.1.119.25426.1.119.2552,046
4826.1.120.0/2126.1.120.1 to 26.1.127.25426.1.127.2552,046
4926.1.128.0/2126.1.128.1 to 26.1.135.25426.1.135.2552,046
5026.1.136.0/2126.1.136.1 to 26.1.143.25426.1.143.2552,046
5126.1.144.0/2126.1.144.1 to 26.1.151.25426.1.151.2552,046
5226.1.152.0/2126.1.152.1 to 26.1.159.25426.1.159.2552,046
5326.1.160.0/2126.1.160.1 to 26.1.167.25426.1.167.2552,046
5426.1.168.0/2126.1.168.1 to 26.1.175.25426.1.175.2552,046
5526.1.176.0/2126.1.176.1 to 26.1.183.25426.1.183.2552,046
5626.1.184.0/2126.1.184.1 to 26.1.191.25426.1.191.2552,046
5726.1.192.0/2126.1.192.1 to 26.1.199.25426.1.199.2552,046
5826.1.200.0/2126.1.200.1 to 26.1.207.25426.1.207.2552,046
5926.1.208.0/2126.1.208.1 to 26.1.215.25426.1.215.2552,046
6026.1.216.0/2126.1.216.1 to 26.1.223.25426.1.223.2552,046
6126.1.224.0/2126.1.224.1 to 26.1.231.25426.1.231.2552,046
6226.1.232.0/2126.1.232.1 to 26.1.239.25426.1.239.2552,046
6326.1.240.0/2126.1.240.1 to 26.1.247.25426.1.247.2552,046
6426.1.248.0/2126.1.248.1 to 26.1.255.25426.1.255.2552,046
6526.2.0.0/2126.2.0.1 to 26.2.7.25426.2.7.2552,046
6626.2.8.0/2126.2.8.1 to 26.2.15.25426.2.15.2552,046
6726.2.16.0/2126.2.16.1 to 26.2.23.25426.2.23.2552,046
6826.2.24.0/2126.2.24.1 to 26.2.31.25426.2.31.2552,046
6926.2.32.0/2126.2.32.1 to 26.2.39.25426.2.39.2552,046
7026.2.40.0/2126.2.40.1 to 26.2.47.25426.2.47.2552,046
7126.2.48.0/2126.2.48.1 to 26.2.55.25426.2.55.2552,046
7226.2.56.0/2126.2.56.1 to 26.2.63.25426.2.63.2552,046
7326.2.64.0/2126.2.64.1 to 26.2.71.25426.2.71.2552,046
7426.2.72.0/2126.2.72.1 to 26.2.79.25426.2.79.2552,046
7526.2.80.0/2126.2.80.1 to 26.2.87.25426.2.87.2552,046
7626.2.88.0/2126.2.88.1 to 26.2.95.25426.2.95.2552,046
7726.2.96.0/2126.2.96.1 to 26.2.103.25426.2.103.2552,046
7826.2.104.0/2126.2.104.1 to 26.2.111.25426.2.111.2552,046
7926.2.112.0/2126.2.112.1 to 26.2.119.25426.2.119.2552,046
8026.2.120.0/2126.2.120.1 to 26.2.127.25426.2.127.2552,046
8126.2.128.0/2126.2.128.1 to 26.2.135.25426.2.135.2552,046
8226.2.136.0/2126.2.136.1 to 26.2.143.25426.2.143.2552,046
8326.2.144.0/2126.2.144.1 to 26.2.151.25426.2.151.2552,046
8426.2.152.0/2126.2.152.1 to 26.2.159.25426.2.159.2552,046
8526.2.160.0/2126.2.160.1 to 26.2.167.25426.2.167.2552,046
8626.2.168.0/2126.2.168.1 to 26.2.175.25426.2.175.2552,046
8726.2.176.0/2126.2.176.1 to 26.2.183.25426.2.183.2552,046
8826.2.184.0/2126.2.184.1 to 26.2.191.25426.2.191.2552,046
8926.2.192.0/2126.2.192.1 to 26.2.199.25426.2.199.2552,046
9026.2.200.0/2126.2.200.1 to 26.2.207.25426.2.207.2552,046
9126.2.208.0/2126.2.208.1 to 26.2.215.25426.2.215.2552,046
9226.2.216.0/2126.2.216.1 to 26.2.223.25426.2.223.2552,046
9326.2.224.0/2126.2.224.1 to 26.2.231.25426.2.231.2552,046
9426.2.232.0/2126.2.232.1 to 26.2.239.25426.2.239.2552,046
9526.2.240.0/2126.2.240.1 to 26.2.247.25426.2.247.2552,046
9626.2.248.0/2126.2.248.1 to 26.2.255.25426.2.255.2552,046
9726.3.0.0/2126.3.0.1 to 26.3.7.25426.3.7.2552,046
9826.3.8.0/2126.3.8.1 to 26.3.15.25426.3.15.2552,046
9926.3.16.0/2126.3.16.1 to 26.3.23.25426.3.23.2552,046
10026.3.24.0/2126.3.24.1 to 26.3.31.25426.3.31.2552,046
10126.3.32.0/2126.3.32.1 to 26.3.39.25426.3.39.2552,046
10226.3.40.0/2126.3.40.1 to 26.3.47.25426.3.47.2552,046
10326.3.48.0/2126.3.48.1 to 26.3.55.25426.3.55.2552,046
10426.3.56.0/2126.3.56.1 to 26.3.63.25426.3.63.2552,046
10526.3.64.0/2126.3.64.1 to 26.3.71.25426.3.71.2552,046
10626.3.72.0/2126.3.72.1 to 26.3.79.25426.3.79.2552,046
10726.3.80.0/2126.3.80.1 to 26.3.87.25426.3.87.2552,046
10826.3.88.0/2126.3.88.1 to 26.3.95.25426.3.95.2552,046
10926.3.96.0/2126.3.96.1 to 26.3.103.25426.3.103.2552,046
11026.3.104.0/2126.3.104.1 to 26.3.111.25426.3.111.2552,046
11126.3.112.0/2126.3.112.1 to 26.3.119.25426.3.119.2552,046
11226.3.120.0/2126.3.120.1 to 26.3.127.25426.3.127.2552,046
11326.3.128.0/2126.3.128.1 to 26.3.135.25426.3.135.2552,046
11426.3.136.0/2126.3.136.1 to 26.3.143.25426.3.143.2552,046
11526.3.144.0/2126.3.144.1 to 26.3.151.25426.3.151.2552,046
11626.3.152.0/2126.3.152.1 to 26.3.159.25426.3.159.2552,046
11726.3.160.0/2126.3.160.1 to 26.3.167.25426.3.167.2552,046
11826.3.168.0/2126.3.168.1 to 26.3.175.25426.3.175.2552,046
11926.3.176.0/2126.3.176.1 to 26.3.183.25426.3.183.2552,046
12026.3.184.0/2126.3.184.1 to 26.3.191.25426.3.191.2552,046
12126.3.192.0/2126.3.192.1 to 26.3.199.25426.3.199.2552,046
12226.3.200.0/2126.3.200.1 to 26.3.207.25426.3.207.2552,046
12326.3.208.0/2126.3.208.1 to 26.3.215.25426.3.215.2552,046
12426.3.216.0/2126.3.216.1 to 26.3.223.25426.3.223.2552,046
12526.3.224.0/2126.3.224.1 to 26.3.231.25426.3.231.2552,046
12626.3.232.0/2126.3.232.1 to 26.3.239.25426.3.239.2552,046
12726.3.240.0/2126.3.240.1 to 26.3.247.25426.3.247.2552,046
12826.3.248.0/2126.3.248.1 to 26.3.255.25426.3.255.2552,046
12926.4.0.0/2126.4.0.1 to 26.4.7.25426.4.7.2552,046
13026.4.8.0/2126.4.8.1 to 26.4.15.25426.4.15.2552,046
13126.4.16.0/2126.4.16.1 to 26.4.23.25426.4.23.2552,046
13226.4.24.0/2126.4.24.1 to 26.4.31.25426.4.31.2552,046
13326.4.32.0/2126.4.32.1 to 26.4.39.25426.4.39.2552,046
13426.4.40.0/2126.4.40.1 to 26.4.47.25426.4.47.2552,046
13526.4.48.0/2126.4.48.1 to 26.4.55.25426.4.55.2552,046
13626.4.56.0/2126.4.56.1 to 26.4.63.25426.4.63.2552,046
13726.4.64.0/2126.4.64.1 to 26.4.71.25426.4.71.2552,046
13826.4.72.0/2126.4.72.1 to 26.4.79.25426.4.79.2552,046
13926.4.80.0/2126.4.80.1 to 26.4.87.25426.4.87.2552,046
14026.4.88.0/2126.4.88.1 to 26.4.95.25426.4.95.2552,046
14126.4.96.0/2126.4.96.1 to 26.4.103.25426.4.103.2552,046
14226.4.104.0/2126.4.104.1 to 26.4.111.25426.4.111.2552,046
14326.4.112.0/2126.4.112.1 to 26.4.119.25426.4.119.2552,046
14426.4.120.0/2126.4.120.1 to 26.4.127.25426.4.127.2552,046
14526.4.128.0/2126.4.128.1 to 26.4.135.25426.4.135.2552,046
14626.4.136.0/2126.4.136.1 to 26.4.143.25426.4.143.2552,046
14726.4.144.0/2126.4.144.1 to 26.4.151.25426.4.151.2552,046
14826.4.152.0/2126.4.152.1 to 26.4.159.25426.4.159.2552,046
14926.4.160.0/2126.4.160.1 to 26.4.167.25426.4.167.2552,046
15026.4.168.0/2126.4.168.1 to 26.4.175.25426.4.175.2552,046
15126.4.176.0/2126.4.176.1 to 26.4.183.25426.4.183.2552,046
15226.4.184.0/2126.4.184.1 to 26.4.191.25426.4.191.2552,046
15326.4.192.0/2126.4.192.1 to 26.4.199.25426.4.199.2552,046
15426.4.200.0/2126.4.200.1 to 26.4.207.25426.4.207.2552,046
15526.4.208.0/2126.4.208.1 to 26.4.215.25426.4.215.2552,046
15626.4.216.0/2126.4.216.1 to 26.4.223.25426.4.223.2552,046
15726.4.224.0/2126.4.224.1 to 26.4.231.25426.4.231.2552,046
15826.4.232.0/2126.4.232.1 to 26.4.239.25426.4.239.2552,046
15926.4.240.0/2126.4.240.1 to 26.4.247.25426.4.247.2552,046
16026.4.248.0/2126.4.248.1 to 26.4.255.25426.4.255.2552,046
16126.5.0.0/2126.5.0.1 to 26.5.7.25426.5.7.2552,046
16226.5.8.0/2126.5.8.1 to 26.5.15.25426.5.15.2552,046
16326.5.16.0/2126.5.16.1 to 26.5.23.25426.5.23.2552,046
16426.5.24.0/2126.5.24.1 to 26.5.31.25426.5.31.2552,046
16526.5.32.0/2126.5.32.1 to 26.5.39.25426.5.39.2552,046
16626.5.40.0/2126.5.40.1 to 26.5.47.25426.5.47.2552,046
16726.5.48.0/2126.5.48.1 to 26.5.55.25426.5.55.2552,046
16826.5.56.0/2126.5.56.1 to 26.5.63.25426.5.63.2552,046
16926.5.64.0/2126.5.64.1 to 26.5.71.25426.5.71.2552,046
17026.5.72.0/2126.5.72.1 to 26.5.79.25426.5.79.2552,046
17126.5.80.0/2126.5.80.1 to 26.5.87.25426.5.87.2552,046
17226.5.88.0/2126.5.88.1 to 26.5.95.25426.5.95.2552,046
17326.5.96.0/2126.5.96.1 to 26.5.103.25426.5.103.2552,046
17426.5.104.0/2126.5.104.1 to 26.5.111.25426.5.111.2552,046
17526.5.112.0/2126.5.112.1 to 26.5.119.25426.5.119.2552,046
17626.5.120.0/2126.5.120.1 to 26.5.127.25426.5.127.2552,046
17726.5.128.0/2126.5.128.1 to 26.5.135.25426.5.135.2552,046
17826.5.136.0/2126.5.136.1 to 26.5.143.25426.5.143.2552,046
17926.5.144.0/2126.5.144.1 to 26.5.151.25426.5.151.2552,046
18026.5.152.0/2126.5.152.1 to 26.5.159.25426.5.159.2552,046
18126.5.160.0/2126.5.160.1 to 26.5.167.25426.5.167.2552,046
18226.5.168.0/2126.5.168.1 to 26.5.175.25426.5.175.2552,046
18326.5.176.0/2126.5.176.1 to 26.5.183.25426.5.183.2552,046
18426.5.184.0/2126.5.184.1 to 26.5.191.25426.5.191.2552,046
18526.5.192.0/2126.5.192.1 to 26.5.199.25426.5.199.2552,046
18626.5.200.0/2126.5.200.1 to 26.5.207.25426.5.207.2552,046
18726.5.208.0/2126.5.208.1 to 26.5.215.25426.5.215.2552,046
18826.5.216.0/2126.5.216.1 to 26.5.223.25426.5.223.2552,046
18926.5.224.0/2126.5.224.1 to 26.5.231.25426.5.231.2552,046
19026.5.232.0/2126.5.232.1 to 26.5.239.25426.5.239.2552,046
19126.5.240.0/2126.5.240.1 to 26.5.247.25426.5.247.2552,046
19226.5.248.0/2126.5.248.1 to 26.5.255.25426.5.255.2552,046
19326.6.0.0/2126.6.0.1 to 26.6.7.25426.6.7.2552,046
19426.6.8.0/2126.6.8.1 to 26.6.15.25426.6.15.2552,046
19526.6.16.0/2126.6.16.1 to 26.6.23.25426.6.23.2552,046
19626.6.24.0/2126.6.24.1 to 26.6.31.25426.6.31.2552,046
19726.6.32.0/2126.6.32.1 to 26.6.39.25426.6.39.2552,046
19826.6.40.0/2126.6.40.1 to 26.6.47.25426.6.47.2552,046
19926.6.48.0/2126.6.48.1 to 26.6.55.25426.6.55.2552,046
20026.6.56.0/2126.6.56.1 to 26.6.63.25426.6.63.2552,046
20126.6.64.0/2126.6.64.1 to 26.6.71.25426.6.71.2552,046
20226.6.72.0/2126.6.72.1 to 26.6.79.25426.6.79.2552,046
20326.6.80.0/2126.6.80.1 to 26.6.87.25426.6.87.2552,046
20426.6.88.0/2126.6.88.1 to 26.6.95.25426.6.95.2552,046
20526.6.96.0/2126.6.96.1 to 26.6.103.25426.6.103.2552,046
20626.6.104.0/2126.6.104.1 to 26.6.111.25426.6.111.2552,046
20726.6.112.0/2126.6.112.1 to 26.6.119.25426.6.119.2552,046
20826.6.120.0/2126.6.120.1 to 26.6.127.25426.6.127.2552,046
20926.6.128.0/2126.6.128.1 to 26.6.135.25426.6.135.2552,046
21026.6.136.0/2126.6.136.1 to 26.6.143.25426.6.143.2552,046
21126.6.144.0/2126.6.144.1 to 26.6.151.25426.6.151.2552,046
21226.6.152.0/2126.6.152.1 to 26.6.159.25426.6.159.2552,046
21326.6.160.0/2126.6.160.1 to 26.6.167.25426.6.167.2552,046
21426.6.168.0/2126.6.168.1 to 26.6.175.25426.6.175.2552,046
21526.6.176.0/2126.6.176.1 to 26.6.183.25426.6.183.2552,046
21626.6.184.0/2126.6.184.1 to 26.6.191.25426.6.191.2552,046
21726.6.192.0/2126.6.192.1 to 26.6.199.25426.6.199.2552,046
21826.6.200.0/2126.6.200.1 to 26.6.207.25426.6.207.2552,046
21926.6.208.0/2126.6.208.1 to 26.6.215.25426.6.215.2552,046
22026.6.216.0/2126.6.216.1 to 26.6.223.25426.6.223.2552,046
22126.6.224.0/2126.6.224.1 to 26.6.231.25426.6.231.2552,046
22226.6.232.0/2126.6.232.1 to 26.6.239.25426.6.239.2552,046
22326.6.240.0/2126.6.240.1 to 26.6.247.25426.6.247.2552,046
22426.6.248.0/2126.6.248.1 to 26.6.255.25426.6.255.2552,046
22526.7.0.0/2126.7.0.1 to 26.7.7.25426.7.7.2552,046
22626.7.8.0/2126.7.8.1 to 26.7.15.25426.7.15.2552,046
22726.7.16.0/2126.7.16.1 to 26.7.23.25426.7.23.2552,046
22826.7.24.0/2126.7.24.1 to 26.7.31.25426.7.31.2552,046
22926.7.32.0/2126.7.32.1 to 26.7.39.25426.7.39.2552,046
23026.7.40.0/2126.7.40.1 to 26.7.47.25426.7.47.2552,046
23126.7.48.0/2126.7.48.1 to 26.7.55.25426.7.55.2552,046
23226.7.56.0/2126.7.56.1 to 26.7.63.25426.7.63.2552,046
23326.7.64.0/2126.7.64.1 to 26.7.71.25426.7.71.2552,046
23426.7.72.0/2126.7.72.1 to 26.7.79.25426.7.79.2552,046
23526.7.80.0/2126.7.80.1 to 26.7.87.25426.7.87.2552,046
23626.7.88.0/2126.7.88.1 to 26.7.95.25426.7.95.2552,046
23726.7.96.0/2126.7.96.1 to 26.7.103.25426.7.103.2552,046
23826.7.104.0/2126.7.104.1 to 26.7.111.25426.7.111.2552,046
23926.7.112.0/2126.7.112.1 to 26.7.119.25426.7.119.2552,046
24026.7.120.0/2126.7.120.1 to 26.7.127.25426.7.127.2552,046
24126.7.128.0/2126.7.128.1 to 26.7.135.25426.7.135.2552,046
24226.7.136.0/2126.7.136.1 to 26.7.143.25426.7.143.2552,046
24326.7.144.0/2126.7.144.1 to 26.7.151.25426.7.151.2552,046
24426.7.152.0/2126.7.152.1 to 26.7.159.25426.7.159.2552,046
24526.7.160.0/2126.7.160.1 to 26.7.167.25426.7.167.2552,046
24626.7.168.0/2126.7.168.1 to 26.7.175.25426.7.175.2552,046
24726.7.176.0/2126.7.176.1 to 26.7.183.25426.7.183.2552,046
24826.7.184.0/2126.7.184.1 to 26.7.191.25426.7.191.2552,046
24926.7.192.0/2126.7.192.1 to 26.7.199.25426.7.199.2552,046
25026.7.200.0/2126.7.200.1 to 26.7.207.25426.7.207.2552,046
25126.7.208.0/2126.7.208.1 to 26.7.215.25426.7.215.2552,046
25226.7.216.0/2126.7.216.1 to 26.7.223.25426.7.223.2552,046
25326.7.224.0/2126.7.224.1 to 26.7.231.25426.7.231.2552,046
25426.7.232.0/2126.7.232.1 to 26.7.239.25426.7.239.2552,046
25526.7.240.0/2126.7.240.1 to 26.7.247.25426.7.247.2552,046
25626.7.248.0/2126.7.248.1 to 26.7.255.25426.7.255.2552,046

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.