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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.

Network31.76.0.0/14
Usable hosts262,142
Subnet mask255.252.0.0
Addresses262,144
Network address
31.76.0.0
Broadcast address
31.79.255.255
First usable
31.76.0.1
Last usable
31.79.255.254
Usable hosts
262,142 (262,144 less the network and broadcast addresses)
Subnet mask
255.252.0.0
Wildcard mask
0.3.255.255 (Cisco ACLs, OSPF)
Prefix length
/14
Type
Public public
Old class
A (default /8)
As numbers
Hex 1F4C0000 · Integer 525074432 to 525336575
Reverse DNS zones
76.31.in-addr.arpa
77.31.in-addr.arpa
78.31.in-addr.arpa
79.31.in-addr.arpa
/14 is not on a 8-bit boundary, so it takes 4 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00011111.01001100.00000000.0000000031.76.0.0
Subnet mask11111111.11111100.00000000.00000000255.252.0.0
Network00011111.01001100.00000000.0000000031.76.0.0
Broadcast00011111.01001111.11111111.1111111131.79.255.255
Split into smaller subnets/24
/15 (2)/16 (4)/17 (8)/18 (16)/19 (32)/20 (64)/21 (128)/22 (256)/23 (512)/24 (1,024)/25 (2,048)/26 (4,096)

31.76.0.0/14 makes 1,024 subnets of /24; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
131.76.0.0/2431.76.0.1 to 31.76.0.25431.76.0.255254
231.76.1.0/2431.76.1.1 to 31.76.1.25431.76.1.255254
331.76.2.0/2431.76.2.1 to 31.76.2.25431.76.2.255254
431.76.3.0/2431.76.3.1 to 31.76.3.25431.76.3.255254
531.76.4.0/2431.76.4.1 to 31.76.4.25431.76.4.255254
631.76.5.0/2431.76.5.1 to 31.76.5.25431.76.5.255254
731.76.6.0/2431.76.6.1 to 31.76.6.25431.76.6.255254
831.76.7.0/2431.76.7.1 to 31.76.7.25431.76.7.255254
931.76.8.0/2431.76.8.1 to 31.76.8.25431.76.8.255254
1031.76.9.0/2431.76.9.1 to 31.76.9.25431.76.9.255254
1131.76.10.0/2431.76.10.1 to 31.76.10.25431.76.10.255254
1231.76.11.0/2431.76.11.1 to 31.76.11.25431.76.11.255254
1331.76.12.0/2431.76.12.1 to 31.76.12.25431.76.12.255254
1431.76.13.0/2431.76.13.1 to 31.76.13.25431.76.13.255254
1531.76.14.0/2431.76.14.1 to 31.76.14.25431.76.14.255254
1631.76.15.0/2431.76.15.1 to 31.76.15.25431.76.15.255254
1731.76.16.0/2431.76.16.1 to 31.76.16.25431.76.16.255254
1831.76.17.0/2431.76.17.1 to 31.76.17.25431.76.17.255254
1931.76.18.0/2431.76.18.1 to 31.76.18.25431.76.18.255254
2031.76.19.0/2431.76.19.1 to 31.76.19.25431.76.19.255254
2131.76.20.0/2431.76.20.1 to 31.76.20.25431.76.20.255254
2231.76.21.0/2431.76.21.1 to 31.76.21.25431.76.21.255254
2331.76.22.0/2431.76.22.1 to 31.76.22.25431.76.22.255254
2431.76.23.0/2431.76.23.1 to 31.76.23.25431.76.23.255254
2531.76.24.0/2431.76.24.1 to 31.76.24.25431.76.24.255254
2631.76.25.0/2431.76.25.1 to 31.76.25.25431.76.25.255254
2731.76.26.0/2431.76.26.1 to 31.76.26.25431.76.26.255254
2831.76.27.0/2431.76.27.1 to 31.76.27.25431.76.27.255254
2931.76.28.0/2431.76.28.1 to 31.76.28.25431.76.28.255254
3031.76.29.0/2431.76.29.1 to 31.76.29.25431.76.29.255254
3131.76.30.0/2431.76.30.1 to 31.76.30.25431.76.30.255254
3231.76.31.0/2431.76.31.1 to 31.76.31.25431.76.31.255254
3331.76.32.0/2431.76.32.1 to 31.76.32.25431.76.32.255254
3431.76.33.0/2431.76.33.1 to 31.76.33.25431.76.33.255254
3531.76.34.0/2431.76.34.1 to 31.76.34.25431.76.34.255254
3631.76.35.0/2431.76.35.1 to 31.76.35.25431.76.35.255254
3731.76.36.0/2431.76.36.1 to 31.76.36.25431.76.36.255254
3831.76.37.0/2431.76.37.1 to 31.76.37.25431.76.37.255254
3931.76.38.0/2431.76.38.1 to 31.76.38.25431.76.38.255254
4031.76.39.0/2431.76.39.1 to 31.76.39.25431.76.39.255254
4131.76.40.0/2431.76.40.1 to 31.76.40.25431.76.40.255254
4231.76.41.0/2431.76.41.1 to 31.76.41.25431.76.41.255254
4331.76.42.0/2431.76.42.1 to 31.76.42.25431.76.42.255254
4431.76.43.0/2431.76.43.1 to 31.76.43.25431.76.43.255254
4531.76.44.0/2431.76.44.1 to 31.76.44.25431.76.44.255254
4631.76.45.0/2431.76.45.1 to 31.76.45.25431.76.45.255254
4731.76.46.0/2431.76.46.1 to 31.76.46.25431.76.46.255254
4831.76.47.0/2431.76.47.1 to 31.76.47.25431.76.47.255254
4931.76.48.0/2431.76.48.1 to 31.76.48.25431.76.48.255254
5031.76.49.0/2431.76.49.1 to 31.76.49.25431.76.49.255254
5131.76.50.0/2431.76.50.1 to 31.76.50.25431.76.50.255254
5231.76.51.0/2431.76.51.1 to 31.76.51.25431.76.51.255254
5331.76.52.0/2431.76.52.1 to 31.76.52.25431.76.52.255254
5431.76.53.0/2431.76.53.1 to 31.76.53.25431.76.53.255254
5531.76.54.0/2431.76.54.1 to 31.76.54.25431.76.54.255254
5631.76.55.0/2431.76.55.1 to 31.76.55.25431.76.55.255254
5731.76.56.0/2431.76.56.1 to 31.76.56.25431.76.56.255254
5831.76.57.0/2431.76.57.1 to 31.76.57.25431.76.57.255254
5931.76.58.0/2431.76.58.1 to 31.76.58.25431.76.58.255254
6031.76.59.0/2431.76.59.1 to 31.76.59.25431.76.59.255254
6131.76.60.0/2431.76.60.1 to 31.76.60.25431.76.60.255254
6231.76.61.0/2431.76.61.1 to 31.76.61.25431.76.61.255254
6331.76.62.0/2431.76.62.1 to 31.76.62.25431.76.62.255254
6431.76.63.0/2431.76.63.1 to 31.76.63.25431.76.63.255254
6531.76.64.0/2431.76.64.1 to 31.76.64.25431.76.64.255254
6631.76.65.0/2431.76.65.1 to 31.76.65.25431.76.65.255254
6731.76.66.0/2431.76.66.1 to 31.76.66.25431.76.66.255254
6831.76.67.0/2431.76.67.1 to 31.76.67.25431.76.67.255254
6931.76.68.0/2431.76.68.1 to 31.76.68.25431.76.68.255254
7031.76.69.0/2431.76.69.1 to 31.76.69.25431.76.69.255254
7131.76.70.0/2431.76.70.1 to 31.76.70.25431.76.70.255254
7231.76.71.0/2431.76.71.1 to 31.76.71.25431.76.71.255254
7331.76.72.0/2431.76.72.1 to 31.76.72.25431.76.72.255254
7431.76.73.0/2431.76.73.1 to 31.76.73.25431.76.73.255254
7531.76.74.0/2431.76.74.1 to 31.76.74.25431.76.74.255254
7631.76.75.0/2431.76.75.1 to 31.76.75.25431.76.75.255254
7731.76.76.0/2431.76.76.1 to 31.76.76.25431.76.76.255254
7831.76.77.0/2431.76.77.1 to 31.76.77.25431.76.77.255254
7931.76.78.0/2431.76.78.1 to 31.76.78.25431.76.78.255254
8031.76.79.0/2431.76.79.1 to 31.76.79.25431.76.79.255254
8131.76.80.0/2431.76.80.1 to 31.76.80.25431.76.80.255254
8231.76.81.0/2431.76.81.1 to 31.76.81.25431.76.81.255254
8331.76.82.0/2431.76.82.1 to 31.76.82.25431.76.82.255254
8431.76.83.0/2431.76.83.1 to 31.76.83.25431.76.83.255254
8531.76.84.0/2431.76.84.1 to 31.76.84.25431.76.84.255254
8631.76.85.0/2431.76.85.1 to 31.76.85.25431.76.85.255254
8731.76.86.0/2431.76.86.1 to 31.76.86.25431.76.86.255254
8831.76.87.0/2431.76.87.1 to 31.76.87.25431.76.87.255254
8931.76.88.0/2431.76.88.1 to 31.76.88.25431.76.88.255254
9031.76.89.0/2431.76.89.1 to 31.76.89.25431.76.89.255254
9131.76.90.0/2431.76.90.1 to 31.76.90.25431.76.90.255254
9231.76.91.0/2431.76.91.1 to 31.76.91.25431.76.91.255254
9331.76.92.0/2431.76.92.1 to 31.76.92.25431.76.92.255254
9431.76.93.0/2431.76.93.1 to 31.76.93.25431.76.93.255254
9531.76.94.0/2431.76.94.1 to 31.76.94.25431.76.94.255254
9631.76.95.0/2431.76.95.1 to 31.76.95.25431.76.95.255254
9731.76.96.0/2431.76.96.1 to 31.76.96.25431.76.96.255254
9831.76.97.0/2431.76.97.1 to 31.76.97.25431.76.97.255254
9931.76.98.0/2431.76.98.1 to 31.76.98.25431.76.98.255254
10031.76.99.0/2431.76.99.1 to 31.76.99.25431.76.99.255254
10131.76.100.0/2431.76.100.1 to 31.76.100.25431.76.100.255254
10231.76.101.0/2431.76.101.1 to 31.76.101.25431.76.101.255254
10331.76.102.0/2431.76.102.1 to 31.76.102.25431.76.102.255254
10431.76.103.0/2431.76.103.1 to 31.76.103.25431.76.103.255254
10531.76.104.0/2431.76.104.1 to 31.76.104.25431.76.104.255254
10631.76.105.0/2431.76.105.1 to 31.76.105.25431.76.105.255254
10731.76.106.0/2431.76.106.1 to 31.76.106.25431.76.106.255254
10831.76.107.0/2431.76.107.1 to 31.76.107.25431.76.107.255254
10931.76.108.0/2431.76.108.1 to 31.76.108.25431.76.108.255254
11031.76.109.0/2431.76.109.1 to 31.76.109.25431.76.109.255254
11131.76.110.0/2431.76.110.1 to 31.76.110.25431.76.110.255254
11231.76.111.0/2431.76.111.1 to 31.76.111.25431.76.111.255254
11331.76.112.0/2431.76.112.1 to 31.76.112.25431.76.112.255254
11431.76.113.0/2431.76.113.1 to 31.76.113.25431.76.113.255254
11531.76.114.0/2431.76.114.1 to 31.76.114.25431.76.114.255254
11631.76.115.0/2431.76.115.1 to 31.76.115.25431.76.115.255254
11731.76.116.0/2431.76.116.1 to 31.76.116.25431.76.116.255254
11831.76.117.0/2431.76.117.1 to 31.76.117.25431.76.117.255254
11931.76.118.0/2431.76.118.1 to 31.76.118.25431.76.118.255254
12031.76.119.0/2431.76.119.1 to 31.76.119.25431.76.119.255254
12131.76.120.0/2431.76.120.1 to 31.76.120.25431.76.120.255254
12231.76.121.0/2431.76.121.1 to 31.76.121.25431.76.121.255254
12331.76.122.0/2431.76.122.1 to 31.76.122.25431.76.122.255254
12431.76.123.0/2431.76.123.1 to 31.76.123.25431.76.123.255254
12531.76.124.0/2431.76.124.1 to 31.76.124.25431.76.124.255254
12631.76.125.0/2431.76.125.1 to 31.76.125.25431.76.125.255254
12731.76.126.0/2431.76.126.1 to 31.76.126.25431.76.126.255254
12831.76.127.0/2431.76.127.1 to 31.76.127.25431.76.127.255254
12931.76.128.0/2431.76.128.1 to 31.76.128.25431.76.128.255254
13031.76.129.0/2431.76.129.1 to 31.76.129.25431.76.129.255254
13131.76.130.0/2431.76.130.1 to 31.76.130.25431.76.130.255254
13231.76.131.0/2431.76.131.1 to 31.76.131.25431.76.131.255254
13331.76.132.0/2431.76.132.1 to 31.76.132.25431.76.132.255254
13431.76.133.0/2431.76.133.1 to 31.76.133.25431.76.133.255254
13531.76.134.0/2431.76.134.1 to 31.76.134.25431.76.134.255254
13631.76.135.0/2431.76.135.1 to 31.76.135.25431.76.135.255254
13731.76.136.0/2431.76.136.1 to 31.76.136.25431.76.136.255254
13831.76.137.0/2431.76.137.1 to 31.76.137.25431.76.137.255254
13931.76.138.0/2431.76.138.1 to 31.76.138.25431.76.138.255254
14031.76.139.0/2431.76.139.1 to 31.76.139.25431.76.139.255254
14131.76.140.0/2431.76.140.1 to 31.76.140.25431.76.140.255254
14231.76.141.0/2431.76.141.1 to 31.76.141.25431.76.141.255254
14331.76.142.0/2431.76.142.1 to 31.76.142.25431.76.142.255254
14431.76.143.0/2431.76.143.1 to 31.76.143.25431.76.143.255254
14531.76.144.0/2431.76.144.1 to 31.76.144.25431.76.144.255254
14631.76.145.0/2431.76.145.1 to 31.76.145.25431.76.145.255254
14731.76.146.0/2431.76.146.1 to 31.76.146.25431.76.146.255254
14831.76.147.0/2431.76.147.1 to 31.76.147.25431.76.147.255254
14931.76.148.0/2431.76.148.1 to 31.76.148.25431.76.148.255254
15031.76.149.0/2431.76.149.1 to 31.76.149.25431.76.149.255254
15131.76.150.0/2431.76.150.1 to 31.76.150.25431.76.150.255254
15231.76.151.0/2431.76.151.1 to 31.76.151.25431.76.151.255254
15331.76.152.0/2431.76.152.1 to 31.76.152.25431.76.152.255254
15431.76.153.0/2431.76.153.1 to 31.76.153.25431.76.153.255254
15531.76.154.0/2431.76.154.1 to 31.76.154.25431.76.154.255254
15631.76.155.0/2431.76.155.1 to 31.76.155.25431.76.155.255254
15731.76.156.0/2431.76.156.1 to 31.76.156.25431.76.156.255254
15831.76.157.0/2431.76.157.1 to 31.76.157.25431.76.157.255254
15931.76.158.0/2431.76.158.1 to 31.76.158.25431.76.158.255254
16031.76.159.0/2431.76.159.1 to 31.76.159.25431.76.159.255254
16131.76.160.0/2431.76.160.1 to 31.76.160.25431.76.160.255254
16231.76.161.0/2431.76.161.1 to 31.76.161.25431.76.161.255254
16331.76.162.0/2431.76.162.1 to 31.76.162.25431.76.162.255254
16431.76.163.0/2431.76.163.1 to 31.76.163.25431.76.163.255254
16531.76.164.0/2431.76.164.1 to 31.76.164.25431.76.164.255254
16631.76.165.0/2431.76.165.1 to 31.76.165.25431.76.165.255254
16731.76.166.0/2431.76.166.1 to 31.76.166.25431.76.166.255254
16831.76.167.0/2431.76.167.1 to 31.76.167.25431.76.167.255254
16931.76.168.0/2431.76.168.1 to 31.76.168.25431.76.168.255254
17031.76.169.0/2431.76.169.1 to 31.76.169.25431.76.169.255254
17131.76.170.0/2431.76.170.1 to 31.76.170.25431.76.170.255254
17231.76.171.0/2431.76.171.1 to 31.76.171.25431.76.171.255254
17331.76.172.0/2431.76.172.1 to 31.76.172.25431.76.172.255254
17431.76.173.0/2431.76.173.1 to 31.76.173.25431.76.173.255254
17531.76.174.0/2431.76.174.1 to 31.76.174.25431.76.174.255254
17631.76.175.0/2431.76.175.1 to 31.76.175.25431.76.175.255254
17731.76.176.0/2431.76.176.1 to 31.76.176.25431.76.176.255254
17831.76.177.0/2431.76.177.1 to 31.76.177.25431.76.177.255254
17931.76.178.0/2431.76.178.1 to 31.76.178.25431.76.178.255254
18031.76.179.0/2431.76.179.1 to 31.76.179.25431.76.179.255254
18131.76.180.0/2431.76.180.1 to 31.76.180.25431.76.180.255254
18231.76.181.0/2431.76.181.1 to 31.76.181.25431.76.181.255254
18331.76.182.0/2431.76.182.1 to 31.76.182.25431.76.182.255254
18431.76.183.0/2431.76.183.1 to 31.76.183.25431.76.183.255254
18531.76.184.0/2431.76.184.1 to 31.76.184.25431.76.184.255254
18631.76.185.0/2431.76.185.1 to 31.76.185.25431.76.185.255254
18731.76.186.0/2431.76.186.1 to 31.76.186.25431.76.186.255254
18831.76.187.0/2431.76.187.1 to 31.76.187.25431.76.187.255254
18931.76.188.0/2431.76.188.1 to 31.76.188.25431.76.188.255254
19031.76.189.0/2431.76.189.1 to 31.76.189.25431.76.189.255254
19131.76.190.0/2431.76.190.1 to 31.76.190.25431.76.190.255254
19231.76.191.0/2431.76.191.1 to 31.76.191.25431.76.191.255254
19331.76.192.0/2431.76.192.1 to 31.76.192.25431.76.192.255254
19431.76.193.0/2431.76.193.1 to 31.76.193.25431.76.193.255254
19531.76.194.0/2431.76.194.1 to 31.76.194.25431.76.194.255254
19631.76.195.0/2431.76.195.1 to 31.76.195.25431.76.195.255254
19731.76.196.0/2431.76.196.1 to 31.76.196.25431.76.196.255254
19831.76.197.0/2431.76.197.1 to 31.76.197.25431.76.197.255254
19931.76.198.0/2431.76.198.1 to 31.76.198.25431.76.198.255254
20031.76.199.0/2431.76.199.1 to 31.76.199.25431.76.199.255254
20131.76.200.0/2431.76.200.1 to 31.76.200.25431.76.200.255254
20231.76.201.0/2431.76.201.1 to 31.76.201.25431.76.201.255254
20331.76.202.0/2431.76.202.1 to 31.76.202.25431.76.202.255254
20431.76.203.0/2431.76.203.1 to 31.76.203.25431.76.203.255254
20531.76.204.0/2431.76.204.1 to 31.76.204.25431.76.204.255254
20631.76.205.0/2431.76.205.1 to 31.76.205.25431.76.205.255254
20731.76.206.0/2431.76.206.1 to 31.76.206.25431.76.206.255254
20831.76.207.0/2431.76.207.1 to 31.76.207.25431.76.207.255254
20931.76.208.0/2431.76.208.1 to 31.76.208.25431.76.208.255254
21031.76.209.0/2431.76.209.1 to 31.76.209.25431.76.209.255254
21131.76.210.0/2431.76.210.1 to 31.76.210.25431.76.210.255254
21231.76.211.0/2431.76.211.1 to 31.76.211.25431.76.211.255254
21331.76.212.0/2431.76.212.1 to 31.76.212.25431.76.212.255254
21431.76.213.0/2431.76.213.1 to 31.76.213.25431.76.213.255254
21531.76.214.0/2431.76.214.1 to 31.76.214.25431.76.214.255254
21631.76.215.0/2431.76.215.1 to 31.76.215.25431.76.215.255254
21731.76.216.0/2431.76.216.1 to 31.76.216.25431.76.216.255254
21831.76.217.0/2431.76.217.1 to 31.76.217.25431.76.217.255254
21931.76.218.0/2431.76.218.1 to 31.76.218.25431.76.218.255254
22031.76.219.0/2431.76.219.1 to 31.76.219.25431.76.219.255254
22131.76.220.0/2431.76.220.1 to 31.76.220.25431.76.220.255254
22231.76.221.0/2431.76.221.1 to 31.76.221.25431.76.221.255254
22331.76.222.0/2431.76.222.1 to 31.76.222.25431.76.222.255254
22431.76.223.0/2431.76.223.1 to 31.76.223.25431.76.223.255254
22531.76.224.0/2431.76.224.1 to 31.76.224.25431.76.224.255254
22631.76.225.0/2431.76.225.1 to 31.76.225.25431.76.225.255254
22731.76.226.0/2431.76.226.1 to 31.76.226.25431.76.226.255254
22831.76.227.0/2431.76.227.1 to 31.76.227.25431.76.227.255254
22931.76.228.0/2431.76.228.1 to 31.76.228.25431.76.228.255254
23031.76.229.0/2431.76.229.1 to 31.76.229.25431.76.229.255254
23131.76.230.0/2431.76.230.1 to 31.76.230.25431.76.230.255254
23231.76.231.0/2431.76.231.1 to 31.76.231.25431.76.231.255254
23331.76.232.0/2431.76.232.1 to 31.76.232.25431.76.232.255254
23431.76.233.0/2431.76.233.1 to 31.76.233.25431.76.233.255254
23531.76.234.0/2431.76.234.1 to 31.76.234.25431.76.234.255254
23631.76.235.0/2431.76.235.1 to 31.76.235.25431.76.235.255254
23731.76.236.0/2431.76.236.1 to 31.76.236.25431.76.236.255254
23831.76.237.0/2431.76.237.1 to 31.76.237.25431.76.237.255254
23931.76.238.0/2431.76.238.1 to 31.76.238.25431.76.238.255254
24031.76.239.0/2431.76.239.1 to 31.76.239.25431.76.239.255254
24131.76.240.0/2431.76.240.1 to 31.76.240.25431.76.240.255254
24231.76.241.0/2431.76.241.1 to 31.76.241.25431.76.241.255254
24331.76.242.0/2431.76.242.1 to 31.76.242.25431.76.242.255254
24431.76.243.0/2431.76.243.1 to 31.76.243.25431.76.243.255254
24531.76.244.0/2431.76.244.1 to 31.76.244.25431.76.244.255254
24631.76.245.0/2431.76.245.1 to 31.76.245.25431.76.245.255254
24731.76.246.0/2431.76.246.1 to 31.76.246.25431.76.246.255254
24831.76.247.0/2431.76.247.1 to 31.76.247.25431.76.247.255254
24931.76.248.0/2431.76.248.1 to 31.76.248.25431.76.248.255254
25031.76.249.0/2431.76.249.1 to 31.76.249.25431.76.249.255254
25131.76.250.0/2431.76.250.1 to 31.76.250.25431.76.250.255254
25231.76.251.0/2431.76.251.1 to 31.76.251.25431.76.251.255254
25331.76.252.0/2431.76.252.1 to 31.76.252.25431.76.252.255254
25431.76.253.0/2431.76.253.1 to 31.76.253.25431.76.253.255254
25531.76.254.0/2431.76.254.1 to 31.76.254.25431.76.254.255254
25631.76.255.0/2431.76.255.1 to 31.76.255.25431.76.255.255254

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.