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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.

Network57.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
57.0.0.0
Broadcast address
57.255.255.255
First usable
57.0.0.1
Last usable
57.255.255.254
Usable hosts
16,777,214 (16,777,216 less the network and broadcast addresses)
Subnet mask
255.0.0.0
Wildcard mask
0.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/8
Type
Public public
Old class
A (default /8)
As numbers
Hex 39000000 · Integer 956301312 to 973078527
Reverse DNS zone
57.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00111001..00000000.00000000.0000000057.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network00111001..00000000.00000000.0000000057.0.0.0
Broadcast00111001..11111111.11111111.1111111157.255.255.255
Split into smaller subnets/16
/9 (2)/10 (4)/11 (8)/12 (16)/13 (32)/14 (64)/15 (128)/16 (256)/17 (512)/18 (1,024)/19 (2,048)/20 (4,096)

57.0.0.0/8 makes 256 subnets of /16.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
157.0.0.0/1657.0.0.1 to 57.0.255.25457.0.255.25565,534
257.1.0.0/1657.1.0.1 to 57.1.255.25457.1.255.25565,534
357.2.0.0/1657.2.0.1 to 57.2.255.25457.2.255.25565,534
457.3.0.0/1657.3.0.1 to 57.3.255.25457.3.255.25565,534
557.4.0.0/1657.4.0.1 to 57.4.255.25457.4.255.25565,534
657.5.0.0/1657.5.0.1 to 57.5.255.25457.5.255.25565,534
757.6.0.0/1657.6.0.1 to 57.6.255.25457.6.255.25565,534
857.7.0.0/1657.7.0.1 to 57.7.255.25457.7.255.25565,534
957.8.0.0/1657.8.0.1 to 57.8.255.25457.8.255.25565,534
1057.9.0.0/1657.9.0.1 to 57.9.255.25457.9.255.25565,534
1157.10.0.0/1657.10.0.1 to 57.10.255.25457.10.255.25565,534
1257.11.0.0/1657.11.0.1 to 57.11.255.25457.11.255.25565,534
1357.12.0.0/1657.12.0.1 to 57.12.255.25457.12.255.25565,534
1457.13.0.0/1657.13.0.1 to 57.13.255.25457.13.255.25565,534
1557.14.0.0/1657.14.0.1 to 57.14.255.25457.14.255.25565,534
1657.15.0.0/1657.15.0.1 to 57.15.255.25457.15.255.25565,534
1757.16.0.0/1657.16.0.1 to 57.16.255.25457.16.255.25565,534
1857.17.0.0/1657.17.0.1 to 57.17.255.25457.17.255.25565,534
1957.18.0.0/1657.18.0.1 to 57.18.255.25457.18.255.25565,534
2057.19.0.0/1657.19.0.1 to 57.19.255.25457.19.255.25565,534
2157.20.0.0/1657.20.0.1 to 57.20.255.25457.20.255.25565,534
2257.21.0.0/1657.21.0.1 to 57.21.255.25457.21.255.25565,534
2357.22.0.0/1657.22.0.1 to 57.22.255.25457.22.255.25565,534
2457.23.0.0/1657.23.0.1 to 57.23.255.25457.23.255.25565,534
2557.24.0.0/1657.24.0.1 to 57.24.255.25457.24.255.25565,534
2657.25.0.0/1657.25.0.1 to 57.25.255.25457.25.255.25565,534
2757.26.0.0/1657.26.0.1 to 57.26.255.25457.26.255.25565,534
2857.27.0.0/1657.27.0.1 to 57.27.255.25457.27.255.25565,534
2957.28.0.0/1657.28.0.1 to 57.28.255.25457.28.255.25565,534
3057.29.0.0/1657.29.0.1 to 57.29.255.25457.29.255.25565,534
3157.30.0.0/1657.30.0.1 to 57.30.255.25457.30.255.25565,534
3257.31.0.0/1657.31.0.1 to 57.31.255.25457.31.255.25565,534
3357.32.0.0/1657.32.0.1 to 57.32.255.25457.32.255.25565,534
3457.33.0.0/1657.33.0.1 to 57.33.255.25457.33.255.25565,534
3557.34.0.0/1657.34.0.1 to 57.34.255.25457.34.255.25565,534
3657.35.0.0/1657.35.0.1 to 57.35.255.25457.35.255.25565,534
3757.36.0.0/1657.36.0.1 to 57.36.255.25457.36.255.25565,534
3857.37.0.0/1657.37.0.1 to 57.37.255.25457.37.255.25565,534
3957.38.0.0/1657.38.0.1 to 57.38.255.25457.38.255.25565,534
4057.39.0.0/1657.39.0.1 to 57.39.255.25457.39.255.25565,534
4157.40.0.0/1657.40.0.1 to 57.40.255.25457.40.255.25565,534
4257.41.0.0/1657.41.0.1 to 57.41.255.25457.41.255.25565,534
4357.42.0.0/1657.42.0.1 to 57.42.255.25457.42.255.25565,534
4457.43.0.0/1657.43.0.1 to 57.43.255.25457.43.255.25565,534
4557.44.0.0/1657.44.0.1 to 57.44.255.25457.44.255.25565,534
4657.45.0.0/1657.45.0.1 to 57.45.255.25457.45.255.25565,534
4757.46.0.0/1657.46.0.1 to 57.46.255.25457.46.255.25565,534
4857.47.0.0/1657.47.0.1 to 57.47.255.25457.47.255.25565,534
4957.48.0.0/1657.48.0.1 to 57.48.255.25457.48.255.25565,534
5057.49.0.0/1657.49.0.1 to 57.49.255.25457.49.255.25565,534
5157.50.0.0/1657.50.0.1 to 57.50.255.25457.50.255.25565,534
5257.51.0.0/1657.51.0.1 to 57.51.255.25457.51.255.25565,534
5357.52.0.0/1657.52.0.1 to 57.52.255.25457.52.255.25565,534
5457.53.0.0/1657.53.0.1 to 57.53.255.25457.53.255.25565,534
5557.54.0.0/1657.54.0.1 to 57.54.255.25457.54.255.25565,534
5657.55.0.0/1657.55.0.1 to 57.55.255.25457.55.255.25565,534
5757.56.0.0/1657.56.0.1 to 57.56.255.25457.56.255.25565,534
5857.57.0.0/1657.57.0.1 to 57.57.255.25457.57.255.25565,534
5957.58.0.0/1657.58.0.1 to 57.58.255.25457.58.255.25565,534
6057.59.0.0/1657.59.0.1 to 57.59.255.25457.59.255.25565,534
6157.60.0.0/1657.60.0.1 to 57.60.255.25457.60.255.25565,534
6257.61.0.0/1657.61.0.1 to 57.61.255.25457.61.255.25565,534
6357.62.0.0/1657.62.0.1 to 57.62.255.25457.62.255.25565,534
6457.63.0.0/1657.63.0.1 to 57.63.255.25457.63.255.25565,534
6557.64.0.0/1657.64.0.1 to 57.64.255.25457.64.255.25565,534
6657.65.0.0/1657.65.0.1 to 57.65.255.25457.65.255.25565,534
6757.66.0.0/1657.66.0.1 to 57.66.255.25457.66.255.25565,534
6857.67.0.0/1657.67.0.1 to 57.67.255.25457.67.255.25565,534
6957.68.0.0/1657.68.0.1 to 57.68.255.25457.68.255.25565,534
7057.69.0.0/1657.69.0.1 to 57.69.255.25457.69.255.25565,534
7157.70.0.0/1657.70.0.1 to 57.70.255.25457.70.255.25565,534
7257.71.0.0/1657.71.0.1 to 57.71.255.25457.71.255.25565,534
7357.72.0.0/1657.72.0.1 to 57.72.255.25457.72.255.25565,534
7457.73.0.0/1657.73.0.1 to 57.73.255.25457.73.255.25565,534
7557.74.0.0/1657.74.0.1 to 57.74.255.25457.74.255.25565,534
7657.75.0.0/1657.75.0.1 to 57.75.255.25457.75.255.25565,534
7757.76.0.0/1657.76.0.1 to 57.76.255.25457.76.255.25565,534
7857.77.0.0/1657.77.0.1 to 57.77.255.25457.77.255.25565,534
7957.78.0.0/1657.78.0.1 to 57.78.255.25457.78.255.25565,534
8057.79.0.0/1657.79.0.1 to 57.79.255.25457.79.255.25565,534
8157.80.0.0/1657.80.0.1 to 57.80.255.25457.80.255.25565,534
8257.81.0.0/1657.81.0.1 to 57.81.255.25457.81.255.25565,534
8357.82.0.0/1657.82.0.1 to 57.82.255.25457.82.255.25565,534
8457.83.0.0/1657.83.0.1 to 57.83.255.25457.83.255.25565,534
8557.84.0.0/1657.84.0.1 to 57.84.255.25457.84.255.25565,534
8657.85.0.0/1657.85.0.1 to 57.85.255.25457.85.255.25565,534
8757.86.0.0/1657.86.0.1 to 57.86.255.25457.86.255.25565,534
8857.87.0.0/1657.87.0.1 to 57.87.255.25457.87.255.25565,534
8957.88.0.0/1657.88.0.1 to 57.88.255.25457.88.255.25565,534
9057.89.0.0/1657.89.0.1 to 57.89.255.25457.89.255.25565,534
9157.90.0.0/1657.90.0.1 to 57.90.255.25457.90.255.25565,534
9257.91.0.0/1657.91.0.1 to 57.91.255.25457.91.255.25565,534
9357.92.0.0/1657.92.0.1 to 57.92.255.25457.92.255.25565,534
9457.93.0.0/1657.93.0.1 to 57.93.255.25457.93.255.25565,534
9557.94.0.0/1657.94.0.1 to 57.94.255.25457.94.255.25565,534
9657.95.0.0/1657.95.0.1 to 57.95.255.25457.95.255.25565,534
9757.96.0.0/1657.96.0.1 to 57.96.255.25457.96.255.25565,534
9857.97.0.0/1657.97.0.1 to 57.97.255.25457.97.255.25565,534
9957.98.0.0/1657.98.0.1 to 57.98.255.25457.98.255.25565,534
10057.99.0.0/1657.99.0.1 to 57.99.255.25457.99.255.25565,534
10157.100.0.0/1657.100.0.1 to 57.100.255.25457.100.255.25565,534
10257.101.0.0/1657.101.0.1 to 57.101.255.25457.101.255.25565,534
10357.102.0.0/1657.102.0.1 to 57.102.255.25457.102.255.25565,534
10457.103.0.0/1657.103.0.1 to 57.103.255.25457.103.255.25565,534
10557.104.0.0/1657.104.0.1 to 57.104.255.25457.104.255.25565,534
10657.105.0.0/1657.105.0.1 to 57.105.255.25457.105.255.25565,534
10757.106.0.0/1657.106.0.1 to 57.106.255.25457.106.255.25565,534
10857.107.0.0/1657.107.0.1 to 57.107.255.25457.107.255.25565,534
10957.108.0.0/1657.108.0.1 to 57.108.255.25457.108.255.25565,534
11057.109.0.0/1657.109.0.1 to 57.109.255.25457.109.255.25565,534
11157.110.0.0/1657.110.0.1 to 57.110.255.25457.110.255.25565,534
11257.111.0.0/1657.111.0.1 to 57.111.255.25457.111.255.25565,534
11357.112.0.0/1657.112.0.1 to 57.112.255.25457.112.255.25565,534
11457.113.0.0/1657.113.0.1 to 57.113.255.25457.113.255.25565,534
11557.114.0.0/1657.114.0.1 to 57.114.255.25457.114.255.25565,534
11657.115.0.0/1657.115.0.1 to 57.115.255.25457.115.255.25565,534
11757.116.0.0/1657.116.0.1 to 57.116.255.25457.116.255.25565,534
11857.117.0.0/1657.117.0.1 to 57.117.255.25457.117.255.25565,534
11957.118.0.0/1657.118.0.1 to 57.118.255.25457.118.255.25565,534
12057.119.0.0/1657.119.0.1 to 57.119.255.25457.119.255.25565,534
12157.120.0.0/1657.120.0.1 to 57.120.255.25457.120.255.25565,534
12257.121.0.0/1657.121.0.1 to 57.121.255.25457.121.255.25565,534
12357.122.0.0/1657.122.0.1 to 57.122.255.25457.122.255.25565,534
12457.123.0.0/1657.123.0.1 to 57.123.255.25457.123.255.25565,534
12557.124.0.0/1657.124.0.1 to 57.124.255.25457.124.255.25565,534
12657.125.0.0/1657.125.0.1 to 57.125.255.25457.125.255.25565,534
12757.126.0.0/1657.126.0.1 to 57.126.255.25457.126.255.25565,534
12857.127.0.0/1657.127.0.1 to 57.127.255.25457.127.255.25565,534
12957.128.0.0/1657.128.0.1 to 57.128.255.25457.128.255.25565,534
13057.129.0.0/1657.129.0.1 to 57.129.255.25457.129.255.25565,534
13157.130.0.0/1657.130.0.1 to 57.130.255.25457.130.255.25565,534
13257.131.0.0/1657.131.0.1 to 57.131.255.25457.131.255.25565,534
13357.132.0.0/1657.132.0.1 to 57.132.255.25457.132.255.25565,534
13457.133.0.0/1657.133.0.1 to 57.133.255.25457.133.255.25565,534
13557.134.0.0/1657.134.0.1 to 57.134.255.25457.134.255.25565,534
13657.135.0.0/1657.135.0.1 to 57.135.255.25457.135.255.25565,534
13757.136.0.0/1657.136.0.1 to 57.136.255.25457.136.255.25565,534
13857.137.0.0/1657.137.0.1 to 57.137.255.25457.137.255.25565,534
13957.138.0.0/1657.138.0.1 to 57.138.255.25457.138.255.25565,534
14057.139.0.0/1657.139.0.1 to 57.139.255.25457.139.255.25565,534
14157.140.0.0/1657.140.0.1 to 57.140.255.25457.140.255.25565,534
14257.141.0.0/1657.141.0.1 to 57.141.255.25457.141.255.25565,534
14357.142.0.0/1657.142.0.1 to 57.142.255.25457.142.255.25565,534
14457.143.0.0/1657.143.0.1 to 57.143.255.25457.143.255.25565,534
14557.144.0.0/1657.144.0.1 to 57.144.255.25457.144.255.25565,534
14657.145.0.0/1657.145.0.1 to 57.145.255.25457.145.255.25565,534
14757.146.0.0/1657.146.0.1 to 57.146.255.25457.146.255.25565,534
14857.147.0.0/1657.147.0.1 to 57.147.255.25457.147.255.25565,534
14957.148.0.0/1657.148.0.1 to 57.148.255.25457.148.255.25565,534
15057.149.0.0/1657.149.0.1 to 57.149.255.25457.149.255.25565,534
15157.150.0.0/1657.150.0.1 to 57.150.255.25457.150.255.25565,534
15257.151.0.0/1657.151.0.1 to 57.151.255.25457.151.255.25565,534
15357.152.0.0/1657.152.0.1 to 57.152.255.25457.152.255.25565,534
15457.153.0.0/1657.153.0.1 to 57.153.255.25457.153.255.25565,534
15557.154.0.0/1657.154.0.1 to 57.154.255.25457.154.255.25565,534
15657.155.0.0/1657.155.0.1 to 57.155.255.25457.155.255.25565,534
15757.156.0.0/1657.156.0.1 to 57.156.255.25457.156.255.25565,534
15857.157.0.0/1657.157.0.1 to 57.157.255.25457.157.255.25565,534
15957.158.0.0/1657.158.0.1 to 57.158.255.25457.158.255.25565,534
16057.159.0.0/1657.159.0.1 to 57.159.255.25457.159.255.25565,534
16157.160.0.0/1657.160.0.1 to 57.160.255.25457.160.255.25565,534
16257.161.0.0/1657.161.0.1 to 57.161.255.25457.161.255.25565,534
16357.162.0.0/1657.162.0.1 to 57.162.255.25457.162.255.25565,534
16457.163.0.0/1657.163.0.1 to 57.163.255.25457.163.255.25565,534
16557.164.0.0/1657.164.0.1 to 57.164.255.25457.164.255.25565,534
16657.165.0.0/1657.165.0.1 to 57.165.255.25457.165.255.25565,534
16757.166.0.0/1657.166.0.1 to 57.166.255.25457.166.255.25565,534
16857.167.0.0/1657.167.0.1 to 57.167.255.25457.167.255.25565,534
16957.168.0.0/1657.168.0.1 to 57.168.255.25457.168.255.25565,534
17057.169.0.0/1657.169.0.1 to 57.169.255.25457.169.255.25565,534
17157.170.0.0/1657.170.0.1 to 57.170.255.25457.170.255.25565,534
17257.171.0.0/1657.171.0.1 to 57.171.255.25457.171.255.25565,534
17357.172.0.0/1657.172.0.1 to 57.172.255.25457.172.255.25565,534
17457.173.0.0/1657.173.0.1 to 57.173.255.25457.173.255.25565,534
17557.174.0.0/1657.174.0.1 to 57.174.255.25457.174.255.25565,534
17657.175.0.0/1657.175.0.1 to 57.175.255.25457.175.255.25565,534
17757.176.0.0/1657.176.0.1 to 57.176.255.25457.176.255.25565,534
17857.177.0.0/1657.177.0.1 to 57.177.255.25457.177.255.25565,534
17957.178.0.0/1657.178.0.1 to 57.178.255.25457.178.255.25565,534
18057.179.0.0/1657.179.0.1 to 57.179.255.25457.179.255.25565,534
18157.180.0.0/1657.180.0.1 to 57.180.255.25457.180.255.25565,534
18257.181.0.0/1657.181.0.1 to 57.181.255.25457.181.255.25565,534
18357.182.0.0/1657.182.0.1 to 57.182.255.25457.182.255.25565,534
18457.183.0.0/1657.183.0.1 to 57.183.255.25457.183.255.25565,534
18557.184.0.0/1657.184.0.1 to 57.184.255.25457.184.255.25565,534
18657.185.0.0/1657.185.0.1 to 57.185.255.25457.185.255.25565,534
18757.186.0.0/1657.186.0.1 to 57.186.255.25457.186.255.25565,534
18857.187.0.0/1657.187.0.1 to 57.187.255.25457.187.255.25565,534
18957.188.0.0/1657.188.0.1 to 57.188.255.25457.188.255.25565,534
19057.189.0.0/1657.189.0.1 to 57.189.255.25457.189.255.25565,534
19157.190.0.0/1657.190.0.1 to 57.190.255.25457.190.255.25565,534
19257.191.0.0/1657.191.0.1 to 57.191.255.25457.191.255.25565,534
19357.192.0.0/1657.192.0.1 to 57.192.255.25457.192.255.25565,534
19457.193.0.0/1657.193.0.1 to 57.193.255.25457.193.255.25565,534
19557.194.0.0/1657.194.0.1 to 57.194.255.25457.194.255.25565,534
19657.195.0.0/1657.195.0.1 to 57.195.255.25457.195.255.25565,534
19757.196.0.0/1657.196.0.1 to 57.196.255.25457.196.255.25565,534
19857.197.0.0/1657.197.0.1 to 57.197.255.25457.197.255.25565,534
19957.198.0.0/1657.198.0.1 to 57.198.255.25457.198.255.25565,534
20057.199.0.0/1657.199.0.1 to 57.199.255.25457.199.255.25565,534
20157.200.0.0/1657.200.0.1 to 57.200.255.25457.200.255.25565,534
20257.201.0.0/1657.201.0.1 to 57.201.255.25457.201.255.25565,534
20357.202.0.0/1657.202.0.1 to 57.202.255.25457.202.255.25565,534
20457.203.0.0/1657.203.0.1 to 57.203.255.25457.203.255.25565,534
20557.204.0.0/1657.204.0.1 to 57.204.255.25457.204.255.25565,534
20657.205.0.0/1657.205.0.1 to 57.205.255.25457.205.255.25565,534
20757.206.0.0/1657.206.0.1 to 57.206.255.25457.206.255.25565,534
20857.207.0.0/1657.207.0.1 to 57.207.255.25457.207.255.25565,534
20957.208.0.0/1657.208.0.1 to 57.208.255.25457.208.255.25565,534
21057.209.0.0/1657.209.0.1 to 57.209.255.25457.209.255.25565,534
21157.210.0.0/1657.210.0.1 to 57.210.255.25457.210.255.25565,534
21257.211.0.0/1657.211.0.1 to 57.211.255.25457.211.255.25565,534
21357.212.0.0/1657.212.0.1 to 57.212.255.25457.212.255.25565,534
21457.213.0.0/1657.213.0.1 to 57.213.255.25457.213.255.25565,534
21557.214.0.0/1657.214.0.1 to 57.214.255.25457.214.255.25565,534
21657.215.0.0/1657.215.0.1 to 57.215.255.25457.215.255.25565,534
21757.216.0.0/1657.216.0.1 to 57.216.255.25457.216.255.25565,534
21857.217.0.0/1657.217.0.1 to 57.217.255.25457.217.255.25565,534
21957.218.0.0/1657.218.0.1 to 57.218.255.25457.218.255.25565,534
22057.219.0.0/1657.219.0.1 to 57.219.255.25457.219.255.25565,534
22157.220.0.0/1657.220.0.1 to 57.220.255.25457.220.255.25565,534
22257.221.0.0/1657.221.0.1 to 57.221.255.25457.221.255.25565,534
22357.222.0.0/1657.222.0.1 to 57.222.255.25457.222.255.25565,534
22457.223.0.0/1657.223.0.1 to 57.223.255.25457.223.255.25565,534
22557.224.0.0/1657.224.0.1 to 57.224.255.25457.224.255.25565,534
22657.225.0.0/1657.225.0.1 to 57.225.255.25457.225.255.25565,534
22757.226.0.0/1657.226.0.1 to 57.226.255.25457.226.255.25565,534
22857.227.0.0/1657.227.0.1 to 57.227.255.25457.227.255.25565,534
22957.228.0.0/1657.228.0.1 to 57.228.255.25457.228.255.25565,534
23057.229.0.0/1657.229.0.1 to 57.229.255.25457.229.255.25565,534
23157.230.0.0/1657.230.0.1 to 57.230.255.25457.230.255.25565,534
23257.231.0.0/1657.231.0.1 to 57.231.255.25457.231.255.25565,534
23357.232.0.0/1657.232.0.1 to 57.232.255.25457.232.255.25565,534
23457.233.0.0/1657.233.0.1 to 57.233.255.25457.233.255.25565,534
23557.234.0.0/1657.234.0.1 to 57.234.255.25457.234.255.25565,534
23657.235.0.0/1657.235.0.1 to 57.235.255.25457.235.255.25565,534
23757.236.0.0/1657.236.0.1 to 57.236.255.25457.236.255.25565,534
23857.237.0.0/1657.237.0.1 to 57.237.255.25457.237.255.25565,534
23957.238.0.0/1657.238.0.1 to 57.238.255.25457.238.255.25565,534
24057.239.0.0/1657.239.0.1 to 57.239.255.25457.239.255.25565,534
24157.240.0.0/1657.240.0.1 to 57.240.255.25457.240.255.25565,534
24257.241.0.0/1657.241.0.1 to 57.241.255.25457.241.255.25565,534
24357.242.0.0/1657.242.0.1 to 57.242.255.25457.242.255.25565,534
24457.243.0.0/1657.243.0.1 to 57.243.255.25457.243.255.25565,534
24557.244.0.0/1657.244.0.1 to 57.244.255.25457.244.255.25565,534
24657.245.0.0/1657.245.0.1 to 57.245.255.25457.245.255.25565,534
24757.246.0.0/1657.246.0.1 to 57.246.255.25457.246.255.25565,534
24857.247.0.0/1657.247.0.1 to 57.247.255.25457.247.255.25565,534
24957.248.0.0/1657.248.0.1 to 57.248.255.25457.248.255.25565,534
25057.249.0.0/1657.249.0.1 to 57.249.255.25457.249.255.25565,534
25157.250.0.0/1657.250.0.1 to 57.250.255.25457.250.255.25565,534
25257.251.0.0/1657.251.0.1 to 57.251.255.25457.251.255.25565,534
25357.252.0.0/1657.252.0.1 to 57.252.255.25457.252.255.25565,534
25457.253.0.0/1657.253.0.1 to 57.253.255.25457.253.255.25565,534
25557.254.0.0/1657.254.0.1 to 57.254.255.25457.254.255.25565,534
25657.255.0.0/1657.255.0.1 to 57.255.255.25457.255.255.25565,534

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.