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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.

Network90.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
90.0.0.0
Broadcast address
91.255.255.255
First usable
90.0.0.1
Last usable
91.255.255.254
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 5A000000 · Integer 1509949440 to 1543503871
Reverse DNS zones
90.in-addr.arpa
91.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
Address01011010.00000000.00000000.0000000090.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network01011010.00000000.00000000.0000000090.0.0.0
Broadcast01011011.11111111.11111111.1111111191.255.255.255
Split into smaller subnets/16
/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)

90.0.0.0/7 makes 512 subnets of /16; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
190.0.0.0/1690.0.0.1 to 90.0.255.25490.0.255.25565,534
290.1.0.0/1690.1.0.1 to 90.1.255.25490.1.255.25565,534
390.2.0.0/1690.2.0.1 to 90.2.255.25490.2.255.25565,534
490.3.0.0/1690.3.0.1 to 90.3.255.25490.3.255.25565,534
590.4.0.0/1690.4.0.1 to 90.4.255.25490.4.255.25565,534
690.5.0.0/1690.5.0.1 to 90.5.255.25490.5.255.25565,534
790.6.0.0/1690.6.0.1 to 90.6.255.25490.6.255.25565,534
890.7.0.0/1690.7.0.1 to 90.7.255.25490.7.255.25565,534
990.8.0.0/1690.8.0.1 to 90.8.255.25490.8.255.25565,534
1090.9.0.0/1690.9.0.1 to 90.9.255.25490.9.255.25565,534
1190.10.0.0/1690.10.0.1 to 90.10.255.25490.10.255.25565,534
1290.11.0.0/1690.11.0.1 to 90.11.255.25490.11.255.25565,534
1390.12.0.0/1690.12.0.1 to 90.12.255.25490.12.255.25565,534
1490.13.0.0/1690.13.0.1 to 90.13.255.25490.13.255.25565,534
1590.14.0.0/1690.14.0.1 to 90.14.255.25490.14.255.25565,534
1690.15.0.0/1690.15.0.1 to 90.15.255.25490.15.255.25565,534
1790.16.0.0/1690.16.0.1 to 90.16.255.25490.16.255.25565,534
1890.17.0.0/1690.17.0.1 to 90.17.255.25490.17.255.25565,534
1990.18.0.0/1690.18.0.1 to 90.18.255.25490.18.255.25565,534
2090.19.0.0/1690.19.0.1 to 90.19.255.25490.19.255.25565,534
2190.20.0.0/1690.20.0.1 to 90.20.255.25490.20.255.25565,534
2290.21.0.0/1690.21.0.1 to 90.21.255.25490.21.255.25565,534
2390.22.0.0/1690.22.0.1 to 90.22.255.25490.22.255.25565,534
2490.23.0.0/1690.23.0.1 to 90.23.255.25490.23.255.25565,534
2590.24.0.0/1690.24.0.1 to 90.24.255.25490.24.255.25565,534
2690.25.0.0/1690.25.0.1 to 90.25.255.25490.25.255.25565,534
2790.26.0.0/1690.26.0.1 to 90.26.255.25490.26.255.25565,534
2890.27.0.0/1690.27.0.1 to 90.27.255.25490.27.255.25565,534
2990.28.0.0/1690.28.0.1 to 90.28.255.25490.28.255.25565,534
3090.29.0.0/1690.29.0.1 to 90.29.255.25490.29.255.25565,534
3190.30.0.0/1690.30.0.1 to 90.30.255.25490.30.255.25565,534
3290.31.0.0/1690.31.0.1 to 90.31.255.25490.31.255.25565,534
3390.32.0.0/1690.32.0.1 to 90.32.255.25490.32.255.25565,534
3490.33.0.0/1690.33.0.1 to 90.33.255.25490.33.255.25565,534
3590.34.0.0/1690.34.0.1 to 90.34.255.25490.34.255.25565,534
3690.35.0.0/1690.35.0.1 to 90.35.255.25490.35.255.25565,534
3790.36.0.0/1690.36.0.1 to 90.36.255.25490.36.255.25565,534
3890.37.0.0/1690.37.0.1 to 90.37.255.25490.37.255.25565,534
3990.38.0.0/1690.38.0.1 to 90.38.255.25490.38.255.25565,534
4090.39.0.0/1690.39.0.1 to 90.39.255.25490.39.255.25565,534
4190.40.0.0/1690.40.0.1 to 90.40.255.25490.40.255.25565,534
4290.41.0.0/1690.41.0.1 to 90.41.255.25490.41.255.25565,534
4390.42.0.0/1690.42.0.1 to 90.42.255.25490.42.255.25565,534
4490.43.0.0/1690.43.0.1 to 90.43.255.25490.43.255.25565,534
4590.44.0.0/1690.44.0.1 to 90.44.255.25490.44.255.25565,534
4690.45.0.0/1690.45.0.1 to 90.45.255.25490.45.255.25565,534
4790.46.0.0/1690.46.0.1 to 90.46.255.25490.46.255.25565,534
4890.47.0.0/1690.47.0.1 to 90.47.255.25490.47.255.25565,534
4990.48.0.0/1690.48.0.1 to 90.48.255.25490.48.255.25565,534
5090.49.0.0/1690.49.0.1 to 90.49.255.25490.49.255.25565,534
5190.50.0.0/1690.50.0.1 to 90.50.255.25490.50.255.25565,534
5290.51.0.0/1690.51.0.1 to 90.51.255.25490.51.255.25565,534
5390.52.0.0/1690.52.0.1 to 90.52.255.25490.52.255.25565,534
5490.53.0.0/1690.53.0.1 to 90.53.255.25490.53.255.25565,534
5590.54.0.0/1690.54.0.1 to 90.54.255.25490.54.255.25565,534
5690.55.0.0/1690.55.0.1 to 90.55.255.25490.55.255.25565,534
5790.56.0.0/1690.56.0.1 to 90.56.255.25490.56.255.25565,534
5890.57.0.0/1690.57.0.1 to 90.57.255.25490.57.255.25565,534
5990.58.0.0/1690.58.0.1 to 90.58.255.25490.58.255.25565,534
6090.59.0.0/1690.59.0.1 to 90.59.255.25490.59.255.25565,534
6190.60.0.0/1690.60.0.1 to 90.60.255.25490.60.255.25565,534
6290.61.0.0/1690.61.0.1 to 90.61.255.25490.61.255.25565,534
6390.62.0.0/1690.62.0.1 to 90.62.255.25490.62.255.25565,534
6490.63.0.0/1690.63.0.1 to 90.63.255.25490.63.255.25565,534
6590.64.0.0/1690.64.0.1 to 90.64.255.25490.64.255.25565,534
6690.65.0.0/1690.65.0.1 to 90.65.255.25490.65.255.25565,534
6790.66.0.0/1690.66.0.1 to 90.66.255.25490.66.255.25565,534
6890.67.0.0/1690.67.0.1 to 90.67.255.25490.67.255.25565,534
6990.68.0.0/1690.68.0.1 to 90.68.255.25490.68.255.25565,534
7090.69.0.0/1690.69.0.1 to 90.69.255.25490.69.255.25565,534
7190.70.0.0/1690.70.0.1 to 90.70.255.25490.70.255.25565,534
7290.71.0.0/1690.71.0.1 to 90.71.255.25490.71.255.25565,534
7390.72.0.0/1690.72.0.1 to 90.72.255.25490.72.255.25565,534
7490.73.0.0/1690.73.0.1 to 90.73.255.25490.73.255.25565,534
7590.74.0.0/1690.74.0.1 to 90.74.255.25490.74.255.25565,534
7690.75.0.0/1690.75.0.1 to 90.75.255.25490.75.255.25565,534
7790.76.0.0/1690.76.0.1 to 90.76.255.25490.76.255.25565,534
7890.77.0.0/1690.77.0.1 to 90.77.255.25490.77.255.25565,534
7990.78.0.0/1690.78.0.1 to 90.78.255.25490.78.255.25565,534
8090.79.0.0/1690.79.0.1 to 90.79.255.25490.79.255.25565,534
8190.80.0.0/1690.80.0.1 to 90.80.255.25490.80.255.25565,534
8290.81.0.0/1690.81.0.1 to 90.81.255.25490.81.255.25565,534
8390.82.0.0/1690.82.0.1 to 90.82.255.25490.82.255.25565,534
8490.83.0.0/1690.83.0.1 to 90.83.255.25490.83.255.25565,534
8590.84.0.0/1690.84.0.1 to 90.84.255.25490.84.255.25565,534
8690.85.0.0/1690.85.0.1 to 90.85.255.25490.85.255.25565,534
8790.86.0.0/1690.86.0.1 to 90.86.255.25490.86.255.25565,534
8890.87.0.0/1690.87.0.1 to 90.87.255.25490.87.255.25565,534
8990.88.0.0/1690.88.0.1 to 90.88.255.25490.88.255.25565,534
9090.89.0.0/1690.89.0.1 to 90.89.255.25490.89.255.25565,534
9190.90.0.0/1690.90.0.1 to 90.90.255.25490.90.255.25565,534
9290.91.0.0/1690.91.0.1 to 90.91.255.25490.91.255.25565,534
9390.92.0.0/1690.92.0.1 to 90.92.255.25490.92.255.25565,534
9490.93.0.0/1690.93.0.1 to 90.93.255.25490.93.255.25565,534
9590.94.0.0/1690.94.0.1 to 90.94.255.25490.94.255.25565,534
9690.95.0.0/1690.95.0.1 to 90.95.255.25490.95.255.25565,534
9790.96.0.0/1690.96.0.1 to 90.96.255.25490.96.255.25565,534
9890.97.0.0/1690.97.0.1 to 90.97.255.25490.97.255.25565,534
9990.98.0.0/1690.98.0.1 to 90.98.255.25490.98.255.25565,534
10090.99.0.0/1690.99.0.1 to 90.99.255.25490.99.255.25565,534
10190.100.0.0/1690.100.0.1 to 90.100.255.25490.100.255.25565,534
10290.101.0.0/1690.101.0.1 to 90.101.255.25490.101.255.25565,534
10390.102.0.0/1690.102.0.1 to 90.102.255.25490.102.255.25565,534
10490.103.0.0/1690.103.0.1 to 90.103.255.25490.103.255.25565,534
10590.104.0.0/1690.104.0.1 to 90.104.255.25490.104.255.25565,534
10690.105.0.0/1690.105.0.1 to 90.105.255.25490.105.255.25565,534
10790.106.0.0/1690.106.0.1 to 90.106.255.25490.106.255.25565,534
10890.107.0.0/1690.107.0.1 to 90.107.255.25490.107.255.25565,534
10990.108.0.0/1690.108.0.1 to 90.108.255.25490.108.255.25565,534
11090.109.0.0/1690.109.0.1 to 90.109.255.25490.109.255.25565,534
11190.110.0.0/1690.110.0.1 to 90.110.255.25490.110.255.25565,534
11290.111.0.0/1690.111.0.1 to 90.111.255.25490.111.255.25565,534
11390.112.0.0/1690.112.0.1 to 90.112.255.25490.112.255.25565,534
11490.113.0.0/1690.113.0.1 to 90.113.255.25490.113.255.25565,534
11590.114.0.0/1690.114.0.1 to 90.114.255.25490.114.255.25565,534
11690.115.0.0/1690.115.0.1 to 90.115.255.25490.115.255.25565,534
11790.116.0.0/1690.116.0.1 to 90.116.255.25490.116.255.25565,534
11890.117.0.0/1690.117.0.1 to 90.117.255.25490.117.255.25565,534
11990.118.0.0/1690.118.0.1 to 90.118.255.25490.118.255.25565,534
12090.119.0.0/1690.119.0.1 to 90.119.255.25490.119.255.25565,534
12190.120.0.0/1690.120.0.1 to 90.120.255.25490.120.255.25565,534
12290.121.0.0/1690.121.0.1 to 90.121.255.25490.121.255.25565,534
12390.122.0.0/1690.122.0.1 to 90.122.255.25490.122.255.25565,534
12490.123.0.0/1690.123.0.1 to 90.123.255.25490.123.255.25565,534
12590.124.0.0/1690.124.0.1 to 90.124.255.25490.124.255.25565,534
12690.125.0.0/1690.125.0.1 to 90.125.255.25490.125.255.25565,534
12790.126.0.0/1690.126.0.1 to 90.126.255.25490.126.255.25565,534
12890.127.0.0/1690.127.0.1 to 90.127.255.25490.127.255.25565,534
12990.128.0.0/1690.128.0.1 to 90.128.255.25490.128.255.25565,534
13090.129.0.0/1690.129.0.1 to 90.129.255.25490.129.255.25565,534
13190.130.0.0/1690.130.0.1 to 90.130.255.25490.130.255.25565,534
13290.131.0.0/1690.131.0.1 to 90.131.255.25490.131.255.25565,534
13390.132.0.0/1690.132.0.1 to 90.132.255.25490.132.255.25565,534
13490.133.0.0/1690.133.0.1 to 90.133.255.25490.133.255.25565,534
13590.134.0.0/1690.134.0.1 to 90.134.255.25490.134.255.25565,534
13690.135.0.0/1690.135.0.1 to 90.135.255.25490.135.255.25565,534
13790.136.0.0/1690.136.0.1 to 90.136.255.25490.136.255.25565,534
13890.137.0.0/1690.137.0.1 to 90.137.255.25490.137.255.25565,534
13990.138.0.0/1690.138.0.1 to 90.138.255.25490.138.255.25565,534
14090.139.0.0/1690.139.0.1 to 90.139.255.25490.139.255.25565,534
14190.140.0.0/1690.140.0.1 to 90.140.255.25490.140.255.25565,534
14290.141.0.0/1690.141.0.1 to 90.141.255.25490.141.255.25565,534
14390.142.0.0/1690.142.0.1 to 90.142.255.25490.142.255.25565,534
14490.143.0.0/1690.143.0.1 to 90.143.255.25490.143.255.25565,534
14590.144.0.0/1690.144.0.1 to 90.144.255.25490.144.255.25565,534
14690.145.0.0/1690.145.0.1 to 90.145.255.25490.145.255.25565,534
14790.146.0.0/1690.146.0.1 to 90.146.255.25490.146.255.25565,534
14890.147.0.0/1690.147.0.1 to 90.147.255.25490.147.255.25565,534
14990.148.0.0/1690.148.0.1 to 90.148.255.25490.148.255.25565,534
15090.149.0.0/1690.149.0.1 to 90.149.255.25490.149.255.25565,534
15190.150.0.0/1690.150.0.1 to 90.150.255.25490.150.255.25565,534
15290.151.0.0/1690.151.0.1 to 90.151.255.25490.151.255.25565,534
15390.152.0.0/1690.152.0.1 to 90.152.255.25490.152.255.25565,534
15490.153.0.0/1690.153.0.1 to 90.153.255.25490.153.255.25565,534
15590.154.0.0/1690.154.0.1 to 90.154.255.25490.154.255.25565,534
15690.155.0.0/1690.155.0.1 to 90.155.255.25490.155.255.25565,534
15790.156.0.0/1690.156.0.1 to 90.156.255.25490.156.255.25565,534
15890.157.0.0/1690.157.0.1 to 90.157.255.25490.157.255.25565,534
15990.158.0.0/1690.158.0.1 to 90.158.255.25490.158.255.25565,534
16090.159.0.0/1690.159.0.1 to 90.159.255.25490.159.255.25565,534
16190.160.0.0/1690.160.0.1 to 90.160.255.25490.160.255.25565,534
16290.161.0.0/1690.161.0.1 to 90.161.255.25490.161.255.25565,534
16390.162.0.0/1690.162.0.1 to 90.162.255.25490.162.255.25565,534
16490.163.0.0/1690.163.0.1 to 90.163.255.25490.163.255.25565,534
16590.164.0.0/1690.164.0.1 to 90.164.255.25490.164.255.25565,534
16690.165.0.0/1690.165.0.1 to 90.165.255.25490.165.255.25565,534
16790.166.0.0/1690.166.0.1 to 90.166.255.25490.166.255.25565,534
16890.167.0.0/1690.167.0.1 to 90.167.255.25490.167.255.25565,534
16990.168.0.0/1690.168.0.1 to 90.168.255.25490.168.255.25565,534
17090.169.0.0/1690.169.0.1 to 90.169.255.25490.169.255.25565,534
17190.170.0.0/1690.170.0.1 to 90.170.255.25490.170.255.25565,534
17290.171.0.0/1690.171.0.1 to 90.171.255.25490.171.255.25565,534
17390.172.0.0/1690.172.0.1 to 90.172.255.25490.172.255.25565,534
17490.173.0.0/1690.173.0.1 to 90.173.255.25490.173.255.25565,534
17590.174.0.0/1690.174.0.1 to 90.174.255.25490.174.255.25565,534
17690.175.0.0/1690.175.0.1 to 90.175.255.25490.175.255.25565,534
17790.176.0.0/1690.176.0.1 to 90.176.255.25490.176.255.25565,534
17890.177.0.0/1690.177.0.1 to 90.177.255.25490.177.255.25565,534
17990.178.0.0/1690.178.0.1 to 90.178.255.25490.178.255.25565,534
18090.179.0.0/1690.179.0.1 to 90.179.255.25490.179.255.25565,534
18190.180.0.0/1690.180.0.1 to 90.180.255.25490.180.255.25565,534
18290.181.0.0/1690.181.0.1 to 90.181.255.25490.181.255.25565,534
18390.182.0.0/1690.182.0.1 to 90.182.255.25490.182.255.25565,534
18490.183.0.0/1690.183.0.1 to 90.183.255.25490.183.255.25565,534
18590.184.0.0/1690.184.0.1 to 90.184.255.25490.184.255.25565,534
18690.185.0.0/1690.185.0.1 to 90.185.255.25490.185.255.25565,534
18790.186.0.0/1690.186.0.1 to 90.186.255.25490.186.255.25565,534
18890.187.0.0/1690.187.0.1 to 90.187.255.25490.187.255.25565,534
18990.188.0.0/1690.188.0.1 to 90.188.255.25490.188.255.25565,534
19090.189.0.0/1690.189.0.1 to 90.189.255.25490.189.255.25565,534
19190.190.0.0/1690.190.0.1 to 90.190.255.25490.190.255.25565,534
19290.191.0.0/1690.191.0.1 to 90.191.255.25490.191.255.25565,534
19390.192.0.0/1690.192.0.1 to 90.192.255.25490.192.255.25565,534
19490.193.0.0/1690.193.0.1 to 90.193.255.25490.193.255.25565,534
19590.194.0.0/1690.194.0.1 to 90.194.255.25490.194.255.25565,534
19690.195.0.0/1690.195.0.1 to 90.195.255.25490.195.255.25565,534
19790.196.0.0/1690.196.0.1 to 90.196.255.25490.196.255.25565,534
19890.197.0.0/1690.197.0.1 to 90.197.255.25490.197.255.25565,534
19990.198.0.0/1690.198.0.1 to 90.198.255.25490.198.255.25565,534
20090.199.0.0/1690.199.0.1 to 90.199.255.25490.199.255.25565,534
20190.200.0.0/1690.200.0.1 to 90.200.255.25490.200.255.25565,534
20290.201.0.0/1690.201.0.1 to 90.201.255.25490.201.255.25565,534
20390.202.0.0/1690.202.0.1 to 90.202.255.25490.202.255.25565,534
20490.203.0.0/1690.203.0.1 to 90.203.255.25490.203.255.25565,534
20590.204.0.0/1690.204.0.1 to 90.204.255.25490.204.255.25565,534
20690.205.0.0/1690.205.0.1 to 90.205.255.25490.205.255.25565,534
20790.206.0.0/1690.206.0.1 to 90.206.255.25490.206.255.25565,534
20890.207.0.0/1690.207.0.1 to 90.207.255.25490.207.255.25565,534
20990.208.0.0/1690.208.0.1 to 90.208.255.25490.208.255.25565,534
21090.209.0.0/1690.209.0.1 to 90.209.255.25490.209.255.25565,534
21190.210.0.0/1690.210.0.1 to 90.210.255.25490.210.255.25565,534
21290.211.0.0/1690.211.0.1 to 90.211.255.25490.211.255.25565,534
21390.212.0.0/1690.212.0.1 to 90.212.255.25490.212.255.25565,534
21490.213.0.0/1690.213.0.1 to 90.213.255.25490.213.255.25565,534
21590.214.0.0/1690.214.0.1 to 90.214.255.25490.214.255.25565,534
21690.215.0.0/1690.215.0.1 to 90.215.255.25490.215.255.25565,534
21790.216.0.0/1690.216.0.1 to 90.216.255.25490.216.255.25565,534
21890.217.0.0/1690.217.0.1 to 90.217.255.25490.217.255.25565,534
21990.218.0.0/1690.218.0.1 to 90.218.255.25490.218.255.25565,534
22090.219.0.0/1690.219.0.1 to 90.219.255.25490.219.255.25565,534
22190.220.0.0/1690.220.0.1 to 90.220.255.25490.220.255.25565,534
22290.221.0.0/1690.221.0.1 to 90.221.255.25490.221.255.25565,534
22390.222.0.0/1690.222.0.1 to 90.222.255.25490.222.255.25565,534
22490.223.0.0/1690.223.0.1 to 90.223.255.25490.223.255.25565,534
22590.224.0.0/1690.224.0.1 to 90.224.255.25490.224.255.25565,534
22690.225.0.0/1690.225.0.1 to 90.225.255.25490.225.255.25565,534
22790.226.0.0/1690.226.0.1 to 90.226.255.25490.226.255.25565,534
22890.227.0.0/1690.227.0.1 to 90.227.255.25490.227.255.25565,534
22990.228.0.0/1690.228.0.1 to 90.228.255.25490.228.255.25565,534
23090.229.0.0/1690.229.0.1 to 90.229.255.25490.229.255.25565,534
23190.230.0.0/1690.230.0.1 to 90.230.255.25490.230.255.25565,534
23290.231.0.0/1690.231.0.1 to 90.231.255.25490.231.255.25565,534
23390.232.0.0/1690.232.0.1 to 90.232.255.25490.232.255.25565,534
23490.233.0.0/1690.233.0.1 to 90.233.255.25490.233.255.25565,534
23590.234.0.0/1690.234.0.1 to 90.234.255.25490.234.255.25565,534
23690.235.0.0/1690.235.0.1 to 90.235.255.25490.235.255.25565,534
23790.236.0.0/1690.236.0.1 to 90.236.255.25490.236.255.25565,534
23890.237.0.0/1690.237.0.1 to 90.237.255.25490.237.255.25565,534
23990.238.0.0/1690.238.0.1 to 90.238.255.25490.238.255.25565,534
24090.239.0.0/1690.239.0.1 to 90.239.255.25490.239.255.25565,534
24190.240.0.0/1690.240.0.1 to 90.240.255.25490.240.255.25565,534
24290.241.0.0/1690.241.0.1 to 90.241.255.25490.241.255.25565,534
24390.242.0.0/1690.242.0.1 to 90.242.255.25490.242.255.25565,534
24490.243.0.0/1690.243.0.1 to 90.243.255.25490.243.255.25565,534
24590.244.0.0/1690.244.0.1 to 90.244.255.25490.244.255.25565,534
24690.245.0.0/1690.245.0.1 to 90.245.255.25490.245.255.25565,534
24790.246.0.0/1690.246.0.1 to 90.246.255.25490.246.255.25565,534
24890.247.0.0/1690.247.0.1 to 90.247.255.25490.247.255.25565,534
24990.248.0.0/1690.248.0.1 to 90.248.255.25490.248.255.25565,534
25090.249.0.0/1690.249.0.1 to 90.249.255.25490.249.255.25565,534
25190.250.0.0/1690.250.0.1 to 90.250.255.25490.250.255.25565,534
25290.251.0.0/1690.251.0.1 to 90.251.255.25490.251.255.25565,534
25390.252.0.0/1690.252.0.1 to 90.252.255.25490.252.255.25565,534
25490.253.0.0/1690.253.0.1 to 90.253.255.25490.253.255.25565,534
25590.254.0.0/1690.254.0.1 to 90.254.255.25490.254.255.25565,534
25690.255.0.0/1690.255.0.1 to 90.255.255.25490.255.255.25565,534

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.