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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.

Network32.0.0.0/8
Usable hosts16,777,214
Subnet mask255.0.0.0
Addresses16,777,216
Network address
32.0.0.0
Broadcast address
32.255.255.255
First usable
32.0.0.1
Last usable
32.255.255.254
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 20000000 · Integer 536870912 to 553648127
Reverse DNS zone
32.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00100000..00000000.00000000.0000000032.0.0.0
Subnet mask11111111..00000000.00000000.00000000255.0.0.0
Network00100000..00000000.00000000.0000000032.0.0.0
Broadcast00100000..11111111.11111111.1111111132.255.255.255
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)

32.0.0.0/8 makes 256 subnets of /16.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
132.0.0.0/1632.0.0.1 to 32.0.255.25432.0.255.25565,534
232.1.0.0/1632.1.0.1 to 32.1.255.25432.1.255.25565,534
332.2.0.0/1632.2.0.1 to 32.2.255.25432.2.255.25565,534
432.3.0.0/1632.3.0.1 to 32.3.255.25432.3.255.25565,534
532.4.0.0/1632.4.0.1 to 32.4.255.25432.4.255.25565,534
632.5.0.0/1632.5.0.1 to 32.5.255.25432.5.255.25565,534
732.6.0.0/1632.6.0.1 to 32.6.255.25432.6.255.25565,534
832.7.0.0/1632.7.0.1 to 32.7.255.25432.7.255.25565,534
932.8.0.0/1632.8.0.1 to 32.8.255.25432.8.255.25565,534
1032.9.0.0/1632.9.0.1 to 32.9.255.25432.9.255.25565,534
1132.10.0.0/1632.10.0.1 to 32.10.255.25432.10.255.25565,534
1232.11.0.0/1632.11.0.1 to 32.11.255.25432.11.255.25565,534
1332.12.0.0/1632.12.0.1 to 32.12.255.25432.12.255.25565,534
1432.13.0.0/1632.13.0.1 to 32.13.255.25432.13.255.25565,534
1532.14.0.0/1632.14.0.1 to 32.14.255.25432.14.255.25565,534
1632.15.0.0/1632.15.0.1 to 32.15.255.25432.15.255.25565,534
1732.16.0.0/1632.16.0.1 to 32.16.255.25432.16.255.25565,534
1832.17.0.0/1632.17.0.1 to 32.17.255.25432.17.255.25565,534
1932.18.0.0/1632.18.0.1 to 32.18.255.25432.18.255.25565,534
2032.19.0.0/1632.19.0.1 to 32.19.255.25432.19.255.25565,534
2132.20.0.0/1632.20.0.1 to 32.20.255.25432.20.255.25565,534
2232.21.0.0/1632.21.0.1 to 32.21.255.25432.21.255.25565,534
2332.22.0.0/1632.22.0.1 to 32.22.255.25432.22.255.25565,534
2432.23.0.0/1632.23.0.1 to 32.23.255.25432.23.255.25565,534
2532.24.0.0/1632.24.0.1 to 32.24.255.25432.24.255.25565,534
2632.25.0.0/1632.25.0.1 to 32.25.255.25432.25.255.25565,534
2732.26.0.0/1632.26.0.1 to 32.26.255.25432.26.255.25565,534
2832.27.0.0/1632.27.0.1 to 32.27.255.25432.27.255.25565,534
2932.28.0.0/1632.28.0.1 to 32.28.255.25432.28.255.25565,534
3032.29.0.0/1632.29.0.1 to 32.29.255.25432.29.255.25565,534
3132.30.0.0/1632.30.0.1 to 32.30.255.25432.30.255.25565,534
3232.31.0.0/1632.31.0.1 to 32.31.255.25432.31.255.25565,534
3332.32.0.0/1632.32.0.1 to 32.32.255.25432.32.255.25565,534
3432.33.0.0/1632.33.0.1 to 32.33.255.25432.33.255.25565,534
3532.34.0.0/1632.34.0.1 to 32.34.255.25432.34.255.25565,534
3632.35.0.0/1632.35.0.1 to 32.35.255.25432.35.255.25565,534
3732.36.0.0/1632.36.0.1 to 32.36.255.25432.36.255.25565,534
3832.37.0.0/1632.37.0.1 to 32.37.255.25432.37.255.25565,534
3932.38.0.0/1632.38.0.1 to 32.38.255.25432.38.255.25565,534
4032.39.0.0/1632.39.0.1 to 32.39.255.25432.39.255.25565,534
4132.40.0.0/1632.40.0.1 to 32.40.255.25432.40.255.25565,534
4232.41.0.0/1632.41.0.1 to 32.41.255.25432.41.255.25565,534
4332.42.0.0/1632.42.0.1 to 32.42.255.25432.42.255.25565,534
4432.43.0.0/1632.43.0.1 to 32.43.255.25432.43.255.25565,534
4532.44.0.0/1632.44.0.1 to 32.44.255.25432.44.255.25565,534
4632.45.0.0/1632.45.0.1 to 32.45.255.25432.45.255.25565,534
4732.46.0.0/1632.46.0.1 to 32.46.255.25432.46.255.25565,534
4832.47.0.0/1632.47.0.1 to 32.47.255.25432.47.255.25565,534
4932.48.0.0/1632.48.0.1 to 32.48.255.25432.48.255.25565,534
5032.49.0.0/1632.49.0.1 to 32.49.255.25432.49.255.25565,534
5132.50.0.0/1632.50.0.1 to 32.50.255.25432.50.255.25565,534
5232.51.0.0/1632.51.0.1 to 32.51.255.25432.51.255.25565,534
5332.52.0.0/1632.52.0.1 to 32.52.255.25432.52.255.25565,534
5432.53.0.0/1632.53.0.1 to 32.53.255.25432.53.255.25565,534
5532.54.0.0/1632.54.0.1 to 32.54.255.25432.54.255.25565,534
5632.55.0.0/1632.55.0.1 to 32.55.255.25432.55.255.25565,534
5732.56.0.0/1632.56.0.1 to 32.56.255.25432.56.255.25565,534
5832.57.0.0/1632.57.0.1 to 32.57.255.25432.57.255.25565,534
5932.58.0.0/1632.58.0.1 to 32.58.255.25432.58.255.25565,534
6032.59.0.0/1632.59.0.1 to 32.59.255.25432.59.255.25565,534
6132.60.0.0/1632.60.0.1 to 32.60.255.25432.60.255.25565,534
6232.61.0.0/1632.61.0.1 to 32.61.255.25432.61.255.25565,534
6332.62.0.0/1632.62.0.1 to 32.62.255.25432.62.255.25565,534
6432.63.0.0/1632.63.0.1 to 32.63.255.25432.63.255.25565,534
6532.64.0.0/1632.64.0.1 to 32.64.255.25432.64.255.25565,534
6632.65.0.0/1632.65.0.1 to 32.65.255.25432.65.255.25565,534
6732.66.0.0/1632.66.0.1 to 32.66.255.25432.66.255.25565,534
6832.67.0.0/1632.67.0.1 to 32.67.255.25432.67.255.25565,534
6932.68.0.0/1632.68.0.1 to 32.68.255.25432.68.255.25565,534
7032.69.0.0/1632.69.0.1 to 32.69.255.25432.69.255.25565,534
7132.70.0.0/1632.70.0.1 to 32.70.255.25432.70.255.25565,534
7232.71.0.0/1632.71.0.1 to 32.71.255.25432.71.255.25565,534
7332.72.0.0/1632.72.0.1 to 32.72.255.25432.72.255.25565,534
7432.73.0.0/1632.73.0.1 to 32.73.255.25432.73.255.25565,534
7532.74.0.0/1632.74.0.1 to 32.74.255.25432.74.255.25565,534
7632.75.0.0/1632.75.0.1 to 32.75.255.25432.75.255.25565,534
7732.76.0.0/1632.76.0.1 to 32.76.255.25432.76.255.25565,534
7832.77.0.0/1632.77.0.1 to 32.77.255.25432.77.255.25565,534
7932.78.0.0/1632.78.0.1 to 32.78.255.25432.78.255.25565,534
8032.79.0.0/1632.79.0.1 to 32.79.255.25432.79.255.25565,534
8132.80.0.0/1632.80.0.1 to 32.80.255.25432.80.255.25565,534
8232.81.0.0/1632.81.0.1 to 32.81.255.25432.81.255.25565,534
8332.82.0.0/1632.82.0.1 to 32.82.255.25432.82.255.25565,534
8432.83.0.0/1632.83.0.1 to 32.83.255.25432.83.255.25565,534
8532.84.0.0/1632.84.0.1 to 32.84.255.25432.84.255.25565,534
8632.85.0.0/1632.85.0.1 to 32.85.255.25432.85.255.25565,534
8732.86.0.0/1632.86.0.1 to 32.86.255.25432.86.255.25565,534
8832.87.0.0/1632.87.0.1 to 32.87.255.25432.87.255.25565,534
8932.88.0.0/1632.88.0.1 to 32.88.255.25432.88.255.25565,534
9032.89.0.0/1632.89.0.1 to 32.89.255.25432.89.255.25565,534
9132.90.0.0/1632.90.0.1 to 32.90.255.25432.90.255.25565,534
9232.91.0.0/1632.91.0.1 to 32.91.255.25432.91.255.25565,534
9332.92.0.0/1632.92.0.1 to 32.92.255.25432.92.255.25565,534
9432.93.0.0/1632.93.0.1 to 32.93.255.25432.93.255.25565,534
9532.94.0.0/1632.94.0.1 to 32.94.255.25432.94.255.25565,534
9632.95.0.0/1632.95.0.1 to 32.95.255.25432.95.255.25565,534
9732.96.0.0/1632.96.0.1 to 32.96.255.25432.96.255.25565,534
9832.97.0.0/1632.97.0.1 to 32.97.255.25432.97.255.25565,534
9932.98.0.0/1632.98.0.1 to 32.98.255.25432.98.255.25565,534
10032.99.0.0/1632.99.0.1 to 32.99.255.25432.99.255.25565,534
10132.100.0.0/1632.100.0.1 to 32.100.255.25432.100.255.25565,534
10232.101.0.0/1632.101.0.1 to 32.101.255.25432.101.255.25565,534
10332.102.0.0/1632.102.0.1 to 32.102.255.25432.102.255.25565,534
10432.103.0.0/1632.103.0.1 to 32.103.255.25432.103.255.25565,534
10532.104.0.0/1632.104.0.1 to 32.104.255.25432.104.255.25565,534
10632.105.0.0/1632.105.0.1 to 32.105.255.25432.105.255.25565,534
10732.106.0.0/1632.106.0.1 to 32.106.255.25432.106.255.25565,534
10832.107.0.0/1632.107.0.1 to 32.107.255.25432.107.255.25565,534
10932.108.0.0/1632.108.0.1 to 32.108.255.25432.108.255.25565,534
11032.109.0.0/1632.109.0.1 to 32.109.255.25432.109.255.25565,534
11132.110.0.0/1632.110.0.1 to 32.110.255.25432.110.255.25565,534
11232.111.0.0/1632.111.0.1 to 32.111.255.25432.111.255.25565,534
11332.112.0.0/1632.112.0.1 to 32.112.255.25432.112.255.25565,534
11432.113.0.0/1632.113.0.1 to 32.113.255.25432.113.255.25565,534
11532.114.0.0/1632.114.0.1 to 32.114.255.25432.114.255.25565,534
11632.115.0.0/1632.115.0.1 to 32.115.255.25432.115.255.25565,534
11732.116.0.0/1632.116.0.1 to 32.116.255.25432.116.255.25565,534
11832.117.0.0/1632.117.0.1 to 32.117.255.25432.117.255.25565,534
11932.118.0.0/1632.118.0.1 to 32.118.255.25432.118.255.25565,534
12032.119.0.0/1632.119.0.1 to 32.119.255.25432.119.255.25565,534
12132.120.0.0/1632.120.0.1 to 32.120.255.25432.120.255.25565,534
12232.121.0.0/1632.121.0.1 to 32.121.255.25432.121.255.25565,534
12332.122.0.0/1632.122.0.1 to 32.122.255.25432.122.255.25565,534
12432.123.0.0/1632.123.0.1 to 32.123.255.25432.123.255.25565,534
12532.124.0.0/1632.124.0.1 to 32.124.255.25432.124.255.25565,534
12632.125.0.0/1632.125.0.1 to 32.125.255.25432.125.255.25565,534
12732.126.0.0/1632.126.0.1 to 32.126.255.25432.126.255.25565,534
12832.127.0.0/1632.127.0.1 to 32.127.255.25432.127.255.25565,534
12932.128.0.0/1632.128.0.1 to 32.128.255.25432.128.255.25565,534
13032.129.0.0/1632.129.0.1 to 32.129.255.25432.129.255.25565,534
13132.130.0.0/1632.130.0.1 to 32.130.255.25432.130.255.25565,534
13232.131.0.0/1632.131.0.1 to 32.131.255.25432.131.255.25565,534
13332.132.0.0/1632.132.0.1 to 32.132.255.25432.132.255.25565,534
13432.133.0.0/1632.133.0.1 to 32.133.255.25432.133.255.25565,534
13532.134.0.0/1632.134.0.1 to 32.134.255.25432.134.255.25565,534
13632.135.0.0/1632.135.0.1 to 32.135.255.25432.135.255.25565,534
13732.136.0.0/1632.136.0.1 to 32.136.255.25432.136.255.25565,534
13832.137.0.0/1632.137.0.1 to 32.137.255.25432.137.255.25565,534
13932.138.0.0/1632.138.0.1 to 32.138.255.25432.138.255.25565,534
14032.139.0.0/1632.139.0.1 to 32.139.255.25432.139.255.25565,534
14132.140.0.0/1632.140.0.1 to 32.140.255.25432.140.255.25565,534
14232.141.0.0/1632.141.0.1 to 32.141.255.25432.141.255.25565,534
14332.142.0.0/1632.142.0.1 to 32.142.255.25432.142.255.25565,534
14432.143.0.0/1632.143.0.1 to 32.143.255.25432.143.255.25565,534
14532.144.0.0/1632.144.0.1 to 32.144.255.25432.144.255.25565,534
14632.145.0.0/1632.145.0.1 to 32.145.255.25432.145.255.25565,534
14732.146.0.0/1632.146.0.1 to 32.146.255.25432.146.255.25565,534
14832.147.0.0/1632.147.0.1 to 32.147.255.25432.147.255.25565,534
14932.148.0.0/1632.148.0.1 to 32.148.255.25432.148.255.25565,534
15032.149.0.0/1632.149.0.1 to 32.149.255.25432.149.255.25565,534
15132.150.0.0/1632.150.0.1 to 32.150.255.25432.150.255.25565,534
15232.151.0.0/1632.151.0.1 to 32.151.255.25432.151.255.25565,534
15332.152.0.0/1632.152.0.1 to 32.152.255.25432.152.255.25565,534
15432.153.0.0/1632.153.0.1 to 32.153.255.25432.153.255.25565,534
15532.154.0.0/1632.154.0.1 to 32.154.255.25432.154.255.25565,534
15632.155.0.0/1632.155.0.1 to 32.155.255.25432.155.255.25565,534
15732.156.0.0/1632.156.0.1 to 32.156.255.25432.156.255.25565,534
15832.157.0.0/1632.157.0.1 to 32.157.255.25432.157.255.25565,534
15932.158.0.0/1632.158.0.1 to 32.158.255.25432.158.255.25565,534
16032.159.0.0/1632.159.0.1 to 32.159.255.25432.159.255.25565,534
16132.160.0.0/1632.160.0.1 to 32.160.255.25432.160.255.25565,534
16232.161.0.0/1632.161.0.1 to 32.161.255.25432.161.255.25565,534
16332.162.0.0/1632.162.0.1 to 32.162.255.25432.162.255.25565,534
16432.163.0.0/1632.163.0.1 to 32.163.255.25432.163.255.25565,534
16532.164.0.0/1632.164.0.1 to 32.164.255.25432.164.255.25565,534
16632.165.0.0/1632.165.0.1 to 32.165.255.25432.165.255.25565,534
16732.166.0.0/1632.166.0.1 to 32.166.255.25432.166.255.25565,534
16832.167.0.0/1632.167.0.1 to 32.167.255.25432.167.255.25565,534
16932.168.0.0/1632.168.0.1 to 32.168.255.25432.168.255.25565,534
17032.169.0.0/1632.169.0.1 to 32.169.255.25432.169.255.25565,534
17132.170.0.0/1632.170.0.1 to 32.170.255.25432.170.255.25565,534
17232.171.0.0/1632.171.0.1 to 32.171.255.25432.171.255.25565,534
17332.172.0.0/1632.172.0.1 to 32.172.255.25432.172.255.25565,534
17432.173.0.0/1632.173.0.1 to 32.173.255.25432.173.255.25565,534
17532.174.0.0/1632.174.0.1 to 32.174.255.25432.174.255.25565,534
17632.175.0.0/1632.175.0.1 to 32.175.255.25432.175.255.25565,534
17732.176.0.0/1632.176.0.1 to 32.176.255.25432.176.255.25565,534
17832.177.0.0/1632.177.0.1 to 32.177.255.25432.177.255.25565,534
17932.178.0.0/1632.178.0.1 to 32.178.255.25432.178.255.25565,534
18032.179.0.0/1632.179.0.1 to 32.179.255.25432.179.255.25565,534
18132.180.0.0/1632.180.0.1 to 32.180.255.25432.180.255.25565,534
18232.181.0.0/1632.181.0.1 to 32.181.255.25432.181.255.25565,534
18332.182.0.0/1632.182.0.1 to 32.182.255.25432.182.255.25565,534
18432.183.0.0/1632.183.0.1 to 32.183.255.25432.183.255.25565,534
18532.184.0.0/1632.184.0.1 to 32.184.255.25432.184.255.25565,534
18632.185.0.0/1632.185.0.1 to 32.185.255.25432.185.255.25565,534
18732.186.0.0/1632.186.0.1 to 32.186.255.25432.186.255.25565,534
18832.187.0.0/1632.187.0.1 to 32.187.255.25432.187.255.25565,534
18932.188.0.0/1632.188.0.1 to 32.188.255.25432.188.255.25565,534
19032.189.0.0/1632.189.0.1 to 32.189.255.25432.189.255.25565,534
19132.190.0.0/1632.190.0.1 to 32.190.255.25432.190.255.25565,534
19232.191.0.0/1632.191.0.1 to 32.191.255.25432.191.255.25565,534
19332.192.0.0/1632.192.0.1 to 32.192.255.25432.192.255.25565,534
19432.193.0.0/1632.193.0.1 to 32.193.255.25432.193.255.25565,534
19532.194.0.0/1632.194.0.1 to 32.194.255.25432.194.255.25565,534
19632.195.0.0/1632.195.0.1 to 32.195.255.25432.195.255.25565,534
19732.196.0.0/1632.196.0.1 to 32.196.255.25432.196.255.25565,534
19832.197.0.0/1632.197.0.1 to 32.197.255.25432.197.255.25565,534
19932.198.0.0/1632.198.0.1 to 32.198.255.25432.198.255.25565,534
20032.199.0.0/1632.199.0.1 to 32.199.255.25432.199.255.25565,534
20132.200.0.0/1632.200.0.1 to 32.200.255.25432.200.255.25565,534
20232.201.0.0/1632.201.0.1 to 32.201.255.25432.201.255.25565,534
20332.202.0.0/1632.202.0.1 to 32.202.255.25432.202.255.25565,534
20432.203.0.0/1632.203.0.1 to 32.203.255.25432.203.255.25565,534
20532.204.0.0/1632.204.0.1 to 32.204.255.25432.204.255.25565,534
20632.205.0.0/1632.205.0.1 to 32.205.255.25432.205.255.25565,534
20732.206.0.0/1632.206.0.1 to 32.206.255.25432.206.255.25565,534
20832.207.0.0/1632.207.0.1 to 32.207.255.25432.207.255.25565,534
20932.208.0.0/1632.208.0.1 to 32.208.255.25432.208.255.25565,534
21032.209.0.0/1632.209.0.1 to 32.209.255.25432.209.255.25565,534
21132.210.0.0/1632.210.0.1 to 32.210.255.25432.210.255.25565,534
21232.211.0.0/1632.211.0.1 to 32.211.255.25432.211.255.25565,534
21332.212.0.0/1632.212.0.1 to 32.212.255.25432.212.255.25565,534
21432.213.0.0/1632.213.0.1 to 32.213.255.25432.213.255.25565,534
21532.214.0.0/1632.214.0.1 to 32.214.255.25432.214.255.25565,534
21632.215.0.0/1632.215.0.1 to 32.215.255.25432.215.255.25565,534
21732.216.0.0/1632.216.0.1 to 32.216.255.25432.216.255.25565,534
21832.217.0.0/1632.217.0.1 to 32.217.255.25432.217.255.25565,534
21932.218.0.0/1632.218.0.1 to 32.218.255.25432.218.255.25565,534
22032.219.0.0/1632.219.0.1 to 32.219.255.25432.219.255.25565,534
22132.220.0.0/1632.220.0.1 to 32.220.255.25432.220.255.25565,534
22232.221.0.0/1632.221.0.1 to 32.221.255.25432.221.255.25565,534
22332.222.0.0/1632.222.0.1 to 32.222.255.25432.222.255.25565,534
22432.223.0.0/1632.223.0.1 to 32.223.255.25432.223.255.25565,534
22532.224.0.0/1632.224.0.1 to 32.224.255.25432.224.255.25565,534
22632.225.0.0/1632.225.0.1 to 32.225.255.25432.225.255.25565,534
22732.226.0.0/1632.226.0.1 to 32.226.255.25432.226.255.25565,534
22832.227.0.0/1632.227.0.1 to 32.227.255.25432.227.255.25565,534
22932.228.0.0/1632.228.0.1 to 32.228.255.25432.228.255.25565,534
23032.229.0.0/1632.229.0.1 to 32.229.255.25432.229.255.25565,534
23132.230.0.0/1632.230.0.1 to 32.230.255.25432.230.255.25565,534
23232.231.0.0/1632.231.0.1 to 32.231.255.25432.231.255.25565,534
23332.232.0.0/1632.232.0.1 to 32.232.255.25432.232.255.25565,534
23432.233.0.0/1632.233.0.1 to 32.233.255.25432.233.255.25565,534
23532.234.0.0/1632.234.0.1 to 32.234.255.25432.234.255.25565,534
23632.235.0.0/1632.235.0.1 to 32.235.255.25432.235.255.25565,534
23732.236.0.0/1632.236.0.1 to 32.236.255.25432.236.255.25565,534
23832.237.0.0/1632.237.0.1 to 32.237.255.25432.237.255.25565,534
23932.238.0.0/1632.238.0.1 to 32.238.255.25432.238.255.25565,534
24032.239.0.0/1632.239.0.1 to 32.239.255.25432.239.255.25565,534
24132.240.0.0/1632.240.0.1 to 32.240.255.25432.240.255.25565,534
24232.241.0.0/1632.241.0.1 to 32.241.255.25432.241.255.25565,534
24332.242.0.0/1632.242.0.1 to 32.242.255.25432.242.255.25565,534
24432.243.0.0/1632.243.0.1 to 32.243.255.25432.243.255.25565,534
24532.244.0.0/1632.244.0.1 to 32.244.255.25432.244.255.25565,534
24632.245.0.0/1632.245.0.1 to 32.245.255.25432.245.255.25565,534
24732.246.0.0/1632.246.0.1 to 32.246.255.25432.246.255.25565,534
24832.247.0.0/1632.247.0.1 to 32.247.255.25432.247.255.25565,534
24932.248.0.0/1632.248.0.1 to 32.248.255.25432.248.255.25565,534
25032.249.0.0/1632.249.0.1 to 32.249.255.25432.249.255.25565,534
25132.250.0.0/1632.250.0.1 to 32.250.255.25432.250.255.25565,534
25232.251.0.0/1632.251.0.1 to 32.251.255.25432.251.255.25565,534
25332.252.0.0/1632.252.0.1 to 32.252.255.25432.252.255.25565,534
25432.253.0.0/1632.253.0.1 to 32.253.255.25432.253.255.25565,534
25532.254.0.0/1632.254.0.1 to 32.254.255.25432.254.255.25565,534
25632.255.0.0/1632.255.0.1 to 32.255.255.25432.255.255.25565,534

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.