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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.

Network44.0.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
44.0.0.0
Broadcast address
44.63.255.255
First usable
44.0.0.1
Last usable
44.63.255.254
Usable hosts
4,194,302 (4,194,304 less the network and broadcast addresses)
Subnet mask
255.192.0.0
Wildcard mask
0.63.255.255 (Cisco ACLs, OSPF)
Prefix length
/10
Type
Public public
Old class
A (default /8)
As numbers
Hex 2C000000 · Integer 738197504 to 742391807
Reverse DNS zones
0.44.in-addr.arpa
1.44.in-addr.arpa
2.44.in-addr.arpa
3.44.in-addr.arpa
4.44.in-addr.arpa
5.44.in-addr.arpa
6.44.in-addr.arpa
7.44.in-addr.arpa
8.44.in-addr.arpa
9.44.in-addr.arpa
10.44.in-addr.arpa
11.44.in-addr.arpa
12.44.in-addr.arpa
13.44.in-addr.arpa
14.44.in-addr.arpa
15.44.in-addr.arpa
and 48 more
/10 is not on a 8-bit boundary, so it takes 64 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00101100.00000000.00000000.0000000044.0.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network00101100.00000000.00000000.0000000044.0.0.0
Broadcast00101100.00111111.11111111.1111111144.63.255.255
Split into smaller subnets/21
/11 (2)/12 (4)/13 (8)/14 (16)/15 (32)/16 (64)/17 (128)/18 (256)/19 (512)/20 (1,024)/21 (2,048)/22 (4,096)

44.0.0.0/10 makes 2,048 subnets of /21; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
144.0.0.0/2144.0.0.1 to 44.0.7.25444.0.7.2552,046
244.0.8.0/2144.0.8.1 to 44.0.15.25444.0.15.2552,046
344.0.16.0/2144.0.16.1 to 44.0.23.25444.0.23.2552,046
444.0.24.0/2144.0.24.1 to 44.0.31.25444.0.31.2552,046
544.0.32.0/2144.0.32.1 to 44.0.39.25444.0.39.2552,046
644.0.40.0/2144.0.40.1 to 44.0.47.25444.0.47.2552,046
744.0.48.0/2144.0.48.1 to 44.0.55.25444.0.55.2552,046
844.0.56.0/2144.0.56.1 to 44.0.63.25444.0.63.2552,046
944.0.64.0/2144.0.64.1 to 44.0.71.25444.0.71.2552,046
1044.0.72.0/2144.0.72.1 to 44.0.79.25444.0.79.2552,046
1144.0.80.0/2144.0.80.1 to 44.0.87.25444.0.87.2552,046
1244.0.88.0/2144.0.88.1 to 44.0.95.25444.0.95.2552,046
1344.0.96.0/2144.0.96.1 to 44.0.103.25444.0.103.2552,046
1444.0.104.0/2144.0.104.1 to 44.0.111.25444.0.111.2552,046
1544.0.112.0/2144.0.112.1 to 44.0.119.25444.0.119.2552,046
1644.0.120.0/2144.0.120.1 to 44.0.127.25444.0.127.2552,046
1744.0.128.0/2144.0.128.1 to 44.0.135.25444.0.135.2552,046
1844.0.136.0/2144.0.136.1 to 44.0.143.25444.0.143.2552,046
1944.0.144.0/2144.0.144.1 to 44.0.151.25444.0.151.2552,046
2044.0.152.0/2144.0.152.1 to 44.0.159.25444.0.159.2552,046
2144.0.160.0/2144.0.160.1 to 44.0.167.25444.0.167.2552,046
2244.0.168.0/2144.0.168.1 to 44.0.175.25444.0.175.2552,046
2344.0.176.0/2144.0.176.1 to 44.0.183.25444.0.183.2552,046
2444.0.184.0/2144.0.184.1 to 44.0.191.25444.0.191.2552,046
2544.0.192.0/2144.0.192.1 to 44.0.199.25444.0.199.2552,046
2644.0.200.0/2144.0.200.1 to 44.0.207.25444.0.207.2552,046
2744.0.208.0/2144.0.208.1 to 44.0.215.25444.0.215.2552,046
2844.0.216.0/2144.0.216.1 to 44.0.223.25444.0.223.2552,046
2944.0.224.0/2144.0.224.1 to 44.0.231.25444.0.231.2552,046
3044.0.232.0/2144.0.232.1 to 44.0.239.25444.0.239.2552,046
3144.0.240.0/2144.0.240.1 to 44.0.247.25444.0.247.2552,046
3244.0.248.0/2144.0.248.1 to 44.0.255.25444.0.255.2552,046
3344.1.0.0/2144.1.0.1 to 44.1.7.25444.1.7.2552,046
3444.1.8.0/2144.1.8.1 to 44.1.15.25444.1.15.2552,046
3544.1.16.0/2144.1.16.1 to 44.1.23.25444.1.23.2552,046
3644.1.24.0/2144.1.24.1 to 44.1.31.25444.1.31.2552,046
3744.1.32.0/2144.1.32.1 to 44.1.39.25444.1.39.2552,046
3844.1.40.0/2144.1.40.1 to 44.1.47.25444.1.47.2552,046
3944.1.48.0/2144.1.48.1 to 44.1.55.25444.1.55.2552,046
4044.1.56.0/2144.1.56.1 to 44.1.63.25444.1.63.2552,046
4144.1.64.0/2144.1.64.1 to 44.1.71.25444.1.71.2552,046
4244.1.72.0/2144.1.72.1 to 44.1.79.25444.1.79.2552,046
4344.1.80.0/2144.1.80.1 to 44.1.87.25444.1.87.2552,046
4444.1.88.0/2144.1.88.1 to 44.1.95.25444.1.95.2552,046
4544.1.96.0/2144.1.96.1 to 44.1.103.25444.1.103.2552,046
4644.1.104.0/2144.1.104.1 to 44.1.111.25444.1.111.2552,046
4744.1.112.0/2144.1.112.1 to 44.1.119.25444.1.119.2552,046
4844.1.120.0/2144.1.120.1 to 44.1.127.25444.1.127.2552,046
4944.1.128.0/2144.1.128.1 to 44.1.135.25444.1.135.2552,046
5044.1.136.0/2144.1.136.1 to 44.1.143.25444.1.143.2552,046
5144.1.144.0/2144.1.144.1 to 44.1.151.25444.1.151.2552,046
5244.1.152.0/2144.1.152.1 to 44.1.159.25444.1.159.2552,046
5344.1.160.0/2144.1.160.1 to 44.1.167.25444.1.167.2552,046
5444.1.168.0/2144.1.168.1 to 44.1.175.25444.1.175.2552,046
5544.1.176.0/2144.1.176.1 to 44.1.183.25444.1.183.2552,046
5644.1.184.0/2144.1.184.1 to 44.1.191.25444.1.191.2552,046
5744.1.192.0/2144.1.192.1 to 44.1.199.25444.1.199.2552,046
5844.1.200.0/2144.1.200.1 to 44.1.207.25444.1.207.2552,046
5944.1.208.0/2144.1.208.1 to 44.1.215.25444.1.215.2552,046
6044.1.216.0/2144.1.216.1 to 44.1.223.25444.1.223.2552,046
6144.1.224.0/2144.1.224.1 to 44.1.231.25444.1.231.2552,046
6244.1.232.0/2144.1.232.1 to 44.1.239.25444.1.239.2552,046
6344.1.240.0/2144.1.240.1 to 44.1.247.25444.1.247.2552,046
6444.1.248.0/2144.1.248.1 to 44.1.255.25444.1.255.2552,046
6544.2.0.0/2144.2.0.1 to 44.2.7.25444.2.7.2552,046
6644.2.8.0/2144.2.8.1 to 44.2.15.25444.2.15.2552,046
6744.2.16.0/2144.2.16.1 to 44.2.23.25444.2.23.2552,046
6844.2.24.0/2144.2.24.1 to 44.2.31.25444.2.31.2552,046
6944.2.32.0/2144.2.32.1 to 44.2.39.25444.2.39.2552,046
7044.2.40.0/2144.2.40.1 to 44.2.47.25444.2.47.2552,046
7144.2.48.0/2144.2.48.1 to 44.2.55.25444.2.55.2552,046
7244.2.56.0/2144.2.56.1 to 44.2.63.25444.2.63.2552,046
7344.2.64.0/2144.2.64.1 to 44.2.71.25444.2.71.2552,046
7444.2.72.0/2144.2.72.1 to 44.2.79.25444.2.79.2552,046
7544.2.80.0/2144.2.80.1 to 44.2.87.25444.2.87.2552,046
7644.2.88.0/2144.2.88.1 to 44.2.95.25444.2.95.2552,046
7744.2.96.0/2144.2.96.1 to 44.2.103.25444.2.103.2552,046
7844.2.104.0/2144.2.104.1 to 44.2.111.25444.2.111.2552,046
7944.2.112.0/2144.2.112.1 to 44.2.119.25444.2.119.2552,046
8044.2.120.0/2144.2.120.1 to 44.2.127.25444.2.127.2552,046
8144.2.128.0/2144.2.128.1 to 44.2.135.25444.2.135.2552,046
8244.2.136.0/2144.2.136.1 to 44.2.143.25444.2.143.2552,046
8344.2.144.0/2144.2.144.1 to 44.2.151.25444.2.151.2552,046
8444.2.152.0/2144.2.152.1 to 44.2.159.25444.2.159.2552,046
8544.2.160.0/2144.2.160.1 to 44.2.167.25444.2.167.2552,046
8644.2.168.0/2144.2.168.1 to 44.2.175.25444.2.175.2552,046
8744.2.176.0/2144.2.176.1 to 44.2.183.25444.2.183.2552,046
8844.2.184.0/2144.2.184.1 to 44.2.191.25444.2.191.2552,046
8944.2.192.0/2144.2.192.1 to 44.2.199.25444.2.199.2552,046
9044.2.200.0/2144.2.200.1 to 44.2.207.25444.2.207.2552,046
9144.2.208.0/2144.2.208.1 to 44.2.215.25444.2.215.2552,046
9244.2.216.0/2144.2.216.1 to 44.2.223.25444.2.223.2552,046
9344.2.224.0/2144.2.224.1 to 44.2.231.25444.2.231.2552,046
9444.2.232.0/2144.2.232.1 to 44.2.239.25444.2.239.2552,046
9544.2.240.0/2144.2.240.1 to 44.2.247.25444.2.247.2552,046
9644.2.248.0/2144.2.248.1 to 44.2.255.25444.2.255.2552,046
9744.3.0.0/2144.3.0.1 to 44.3.7.25444.3.7.2552,046
9844.3.8.0/2144.3.8.1 to 44.3.15.25444.3.15.2552,046
9944.3.16.0/2144.3.16.1 to 44.3.23.25444.3.23.2552,046
10044.3.24.0/2144.3.24.1 to 44.3.31.25444.3.31.2552,046
10144.3.32.0/2144.3.32.1 to 44.3.39.25444.3.39.2552,046
10244.3.40.0/2144.3.40.1 to 44.3.47.25444.3.47.2552,046
10344.3.48.0/2144.3.48.1 to 44.3.55.25444.3.55.2552,046
10444.3.56.0/2144.3.56.1 to 44.3.63.25444.3.63.2552,046
10544.3.64.0/2144.3.64.1 to 44.3.71.25444.3.71.2552,046
10644.3.72.0/2144.3.72.1 to 44.3.79.25444.3.79.2552,046
10744.3.80.0/2144.3.80.1 to 44.3.87.25444.3.87.2552,046
10844.3.88.0/2144.3.88.1 to 44.3.95.25444.3.95.2552,046
10944.3.96.0/2144.3.96.1 to 44.3.103.25444.3.103.2552,046
11044.3.104.0/2144.3.104.1 to 44.3.111.25444.3.111.2552,046
11144.3.112.0/2144.3.112.1 to 44.3.119.25444.3.119.2552,046
11244.3.120.0/2144.3.120.1 to 44.3.127.25444.3.127.2552,046
11344.3.128.0/2144.3.128.1 to 44.3.135.25444.3.135.2552,046
11444.3.136.0/2144.3.136.1 to 44.3.143.25444.3.143.2552,046
11544.3.144.0/2144.3.144.1 to 44.3.151.25444.3.151.2552,046
11644.3.152.0/2144.3.152.1 to 44.3.159.25444.3.159.2552,046
11744.3.160.0/2144.3.160.1 to 44.3.167.25444.3.167.2552,046
11844.3.168.0/2144.3.168.1 to 44.3.175.25444.3.175.2552,046
11944.3.176.0/2144.3.176.1 to 44.3.183.25444.3.183.2552,046
12044.3.184.0/2144.3.184.1 to 44.3.191.25444.3.191.2552,046
12144.3.192.0/2144.3.192.1 to 44.3.199.25444.3.199.2552,046
12244.3.200.0/2144.3.200.1 to 44.3.207.25444.3.207.2552,046
12344.3.208.0/2144.3.208.1 to 44.3.215.25444.3.215.2552,046
12444.3.216.0/2144.3.216.1 to 44.3.223.25444.3.223.2552,046
12544.3.224.0/2144.3.224.1 to 44.3.231.25444.3.231.2552,046
12644.3.232.0/2144.3.232.1 to 44.3.239.25444.3.239.2552,046
12744.3.240.0/2144.3.240.1 to 44.3.247.25444.3.247.2552,046
12844.3.248.0/2144.3.248.1 to 44.3.255.25444.3.255.2552,046
12944.4.0.0/2144.4.0.1 to 44.4.7.25444.4.7.2552,046
13044.4.8.0/2144.4.8.1 to 44.4.15.25444.4.15.2552,046
13144.4.16.0/2144.4.16.1 to 44.4.23.25444.4.23.2552,046
13244.4.24.0/2144.4.24.1 to 44.4.31.25444.4.31.2552,046
13344.4.32.0/2144.4.32.1 to 44.4.39.25444.4.39.2552,046
13444.4.40.0/2144.4.40.1 to 44.4.47.25444.4.47.2552,046
13544.4.48.0/2144.4.48.1 to 44.4.55.25444.4.55.2552,046
13644.4.56.0/2144.4.56.1 to 44.4.63.25444.4.63.2552,046
13744.4.64.0/2144.4.64.1 to 44.4.71.25444.4.71.2552,046
13844.4.72.0/2144.4.72.1 to 44.4.79.25444.4.79.2552,046
13944.4.80.0/2144.4.80.1 to 44.4.87.25444.4.87.2552,046
14044.4.88.0/2144.4.88.1 to 44.4.95.25444.4.95.2552,046
14144.4.96.0/2144.4.96.1 to 44.4.103.25444.4.103.2552,046
14244.4.104.0/2144.4.104.1 to 44.4.111.25444.4.111.2552,046
14344.4.112.0/2144.4.112.1 to 44.4.119.25444.4.119.2552,046
14444.4.120.0/2144.4.120.1 to 44.4.127.25444.4.127.2552,046
14544.4.128.0/2144.4.128.1 to 44.4.135.25444.4.135.2552,046
14644.4.136.0/2144.4.136.1 to 44.4.143.25444.4.143.2552,046
14744.4.144.0/2144.4.144.1 to 44.4.151.25444.4.151.2552,046
14844.4.152.0/2144.4.152.1 to 44.4.159.25444.4.159.2552,046
14944.4.160.0/2144.4.160.1 to 44.4.167.25444.4.167.2552,046
15044.4.168.0/2144.4.168.1 to 44.4.175.25444.4.175.2552,046
15144.4.176.0/2144.4.176.1 to 44.4.183.25444.4.183.2552,046
15244.4.184.0/2144.4.184.1 to 44.4.191.25444.4.191.2552,046
15344.4.192.0/2144.4.192.1 to 44.4.199.25444.4.199.2552,046
15444.4.200.0/2144.4.200.1 to 44.4.207.25444.4.207.2552,046
15544.4.208.0/2144.4.208.1 to 44.4.215.25444.4.215.2552,046
15644.4.216.0/2144.4.216.1 to 44.4.223.25444.4.223.2552,046
15744.4.224.0/2144.4.224.1 to 44.4.231.25444.4.231.2552,046
15844.4.232.0/2144.4.232.1 to 44.4.239.25444.4.239.2552,046
15944.4.240.0/2144.4.240.1 to 44.4.247.25444.4.247.2552,046
16044.4.248.0/2144.4.248.1 to 44.4.255.25444.4.255.2552,046
16144.5.0.0/2144.5.0.1 to 44.5.7.25444.5.7.2552,046
16244.5.8.0/2144.5.8.1 to 44.5.15.25444.5.15.2552,046
16344.5.16.0/2144.5.16.1 to 44.5.23.25444.5.23.2552,046
16444.5.24.0/2144.5.24.1 to 44.5.31.25444.5.31.2552,046
16544.5.32.0/2144.5.32.1 to 44.5.39.25444.5.39.2552,046
16644.5.40.0/2144.5.40.1 to 44.5.47.25444.5.47.2552,046
16744.5.48.0/2144.5.48.1 to 44.5.55.25444.5.55.2552,046
16844.5.56.0/2144.5.56.1 to 44.5.63.25444.5.63.2552,046
16944.5.64.0/2144.5.64.1 to 44.5.71.25444.5.71.2552,046
17044.5.72.0/2144.5.72.1 to 44.5.79.25444.5.79.2552,046
17144.5.80.0/2144.5.80.1 to 44.5.87.25444.5.87.2552,046
17244.5.88.0/2144.5.88.1 to 44.5.95.25444.5.95.2552,046
17344.5.96.0/2144.5.96.1 to 44.5.103.25444.5.103.2552,046
17444.5.104.0/2144.5.104.1 to 44.5.111.25444.5.111.2552,046
17544.5.112.0/2144.5.112.1 to 44.5.119.25444.5.119.2552,046
17644.5.120.0/2144.5.120.1 to 44.5.127.25444.5.127.2552,046
17744.5.128.0/2144.5.128.1 to 44.5.135.25444.5.135.2552,046
17844.5.136.0/2144.5.136.1 to 44.5.143.25444.5.143.2552,046
17944.5.144.0/2144.5.144.1 to 44.5.151.25444.5.151.2552,046
18044.5.152.0/2144.5.152.1 to 44.5.159.25444.5.159.2552,046
18144.5.160.0/2144.5.160.1 to 44.5.167.25444.5.167.2552,046
18244.5.168.0/2144.5.168.1 to 44.5.175.25444.5.175.2552,046
18344.5.176.0/2144.5.176.1 to 44.5.183.25444.5.183.2552,046
18444.5.184.0/2144.5.184.1 to 44.5.191.25444.5.191.2552,046
18544.5.192.0/2144.5.192.1 to 44.5.199.25444.5.199.2552,046
18644.5.200.0/2144.5.200.1 to 44.5.207.25444.5.207.2552,046
18744.5.208.0/2144.5.208.1 to 44.5.215.25444.5.215.2552,046
18844.5.216.0/2144.5.216.1 to 44.5.223.25444.5.223.2552,046
18944.5.224.0/2144.5.224.1 to 44.5.231.25444.5.231.2552,046
19044.5.232.0/2144.5.232.1 to 44.5.239.25444.5.239.2552,046
19144.5.240.0/2144.5.240.1 to 44.5.247.25444.5.247.2552,046
19244.5.248.0/2144.5.248.1 to 44.5.255.25444.5.255.2552,046
19344.6.0.0/2144.6.0.1 to 44.6.7.25444.6.7.2552,046
19444.6.8.0/2144.6.8.1 to 44.6.15.25444.6.15.2552,046
19544.6.16.0/2144.6.16.1 to 44.6.23.25444.6.23.2552,046
19644.6.24.0/2144.6.24.1 to 44.6.31.25444.6.31.2552,046
19744.6.32.0/2144.6.32.1 to 44.6.39.25444.6.39.2552,046
19844.6.40.0/2144.6.40.1 to 44.6.47.25444.6.47.2552,046
19944.6.48.0/2144.6.48.1 to 44.6.55.25444.6.55.2552,046
20044.6.56.0/2144.6.56.1 to 44.6.63.25444.6.63.2552,046
20144.6.64.0/2144.6.64.1 to 44.6.71.25444.6.71.2552,046
20244.6.72.0/2144.6.72.1 to 44.6.79.25444.6.79.2552,046
20344.6.80.0/2144.6.80.1 to 44.6.87.25444.6.87.2552,046
20444.6.88.0/2144.6.88.1 to 44.6.95.25444.6.95.2552,046
20544.6.96.0/2144.6.96.1 to 44.6.103.25444.6.103.2552,046
20644.6.104.0/2144.6.104.1 to 44.6.111.25444.6.111.2552,046
20744.6.112.0/2144.6.112.1 to 44.6.119.25444.6.119.2552,046
20844.6.120.0/2144.6.120.1 to 44.6.127.25444.6.127.2552,046
20944.6.128.0/2144.6.128.1 to 44.6.135.25444.6.135.2552,046
21044.6.136.0/2144.6.136.1 to 44.6.143.25444.6.143.2552,046
21144.6.144.0/2144.6.144.1 to 44.6.151.25444.6.151.2552,046
21244.6.152.0/2144.6.152.1 to 44.6.159.25444.6.159.2552,046
21344.6.160.0/2144.6.160.1 to 44.6.167.25444.6.167.2552,046
21444.6.168.0/2144.6.168.1 to 44.6.175.25444.6.175.2552,046
21544.6.176.0/2144.6.176.1 to 44.6.183.25444.6.183.2552,046
21644.6.184.0/2144.6.184.1 to 44.6.191.25444.6.191.2552,046
21744.6.192.0/2144.6.192.1 to 44.6.199.25444.6.199.2552,046
21844.6.200.0/2144.6.200.1 to 44.6.207.25444.6.207.2552,046
21944.6.208.0/2144.6.208.1 to 44.6.215.25444.6.215.2552,046
22044.6.216.0/2144.6.216.1 to 44.6.223.25444.6.223.2552,046
22144.6.224.0/2144.6.224.1 to 44.6.231.25444.6.231.2552,046
22244.6.232.0/2144.6.232.1 to 44.6.239.25444.6.239.2552,046
22344.6.240.0/2144.6.240.1 to 44.6.247.25444.6.247.2552,046
22444.6.248.0/2144.6.248.1 to 44.6.255.25444.6.255.2552,046
22544.7.0.0/2144.7.0.1 to 44.7.7.25444.7.7.2552,046
22644.7.8.0/2144.7.8.1 to 44.7.15.25444.7.15.2552,046
22744.7.16.0/2144.7.16.1 to 44.7.23.25444.7.23.2552,046
22844.7.24.0/2144.7.24.1 to 44.7.31.25444.7.31.2552,046
22944.7.32.0/2144.7.32.1 to 44.7.39.25444.7.39.2552,046
23044.7.40.0/2144.7.40.1 to 44.7.47.25444.7.47.2552,046
23144.7.48.0/2144.7.48.1 to 44.7.55.25444.7.55.2552,046
23244.7.56.0/2144.7.56.1 to 44.7.63.25444.7.63.2552,046
23344.7.64.0/2144.7.64.1 to 44.7.71.25444.7.71.2552,046
23444.7.72.0/2144.7.72.1 to 44.7.79.25444.7.79.2552,046
23544.7.80.0/2144.7.80.1 to 44.7.87.25444.7.87.2552,046
23644.7.88.0/2144.7.88.1 to 44.7.95.25444.7.95.2552,046
23744.7.96.0/2144.7.96.1 to 44.7.103.25444.7.103.2552,046
23844.7.104.0/2144.7.104.1 to 44.7.111.25444.7.111.2552,046
23944.7.112.0/2144.7.112.1 to 44.7.119.25444.7.119.2552,046
24044.7.120.0/2144.7.120.1 to 44.7.127.25444.7.127.2552,046
24144.7.128.0/2144.7.128.1 to 44.7.135.25444.7.135.2552,046
24244.7.136.0/2144.7.136.1 to 44.7.143.25444.7.143.2552,046
24344.7.144.0/2144.7.144.1 to 44.7.151.25444.7.151.2552,046
24444.7.152.0/2144.7.152.1 to 44.7.159.25444.7.159.2552,046
24544.7.160.0/2144.7.160.1 to 44.7.167.25444.7.167.2552,046
24644.7.168.0/2144.7.168.1 to 44.7.175.25444.7.175.2552,046
24744.7.176.0/2144.7.176.1 to 44.7.183.25444.7.183.2552,046
24844.7.184.0/2144.7.184.1 to 44.7.191.25444.7.191.2552,046
24944.7.192.0/2144.7.192.1 to 44.7.199.25444.7.199.2552,046
25044.7.200.0/2144.7.200.1 to 44.7.207.25444.7.207.2552,046
25144.7.208.0/2144.7.208.1 to 44.7.215.25444.7.215.2552,046
25244.7.216.0/2144.7.216.1 to 44.7.223.25444.7.223.2552,046
25344.7.224.0/2144.7.224.1 to 44.7.231.25444.7.231.2552,046
25444.7.232.0/2144.7.232.1 to 44.7.239.25444.7.239.2552,046
25544.7.240.0/2144.7.240.1 to 44.7.247.25444.7.247.2552,046
25644.7.248.0/2144.7.248.1 to 44.7.255.25444.7.255.2552,046

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.