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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.

Network76.2.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
76.2.0.0
Broadcast address
76.3.255.255
First usable
76.2.0.1
Last usable
76.3.255.254
Usable hosts
131,070 (131,072 less the network and broadcast addresses)
Subnet mask
255.254.0.0
Wildcard mask
0.1.255.255 (Cisco ACLs, OSPF)
Prefix length
/15
Type
Public public
Old class
A (default /8)
As numbers
Hex 4C020000 · Integer 1275199488 to 1275330559
Reverse DNS zones
2.76.in-addr.arpa
3.76.in-addr.arpa
/15 is not on a 8-bit boundary, so it takes 2 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01001100.00000010.00000000.0000000076.2.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network01001100.00000010.00000000.0000000076.2.0.0
Broadcast01001100.00000011.11111111.1111111176.3.255.255
Split into smaller subnets/23
/16 (2)/17 (4)/18 (8)/19 (16)/20 (32)/21 (64)/22 (128)/23 (256)/24 (512)/25 (1,024)/26 (2,048)/27 (4,096)

76.2.0.0/15 makes 256 subnets of /23.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
176.2.0.0/2376.2.0.1 to 76.2.1.25476.2.1.255510
276.2.2.0/2376.2.2.1 to 76.2.3.25476.2.3.255510
376.2.4.0/2376.2.4.1 to 76.2.5.25476.2.5.255510
476.2.6.0/2376.2.6.1 to 76.2.7.25476.2.7.255510
576.2.8.0/2376.2.8.1 to 76.2.9.25476.2.9.255510
676.2.10.0/2376.2.10.1 to 76.2.11.25476.2.11.255510
776.2.12.0/2376.2.12.1 to 76.2.13.25476.2.13.255510
876.2.14.0/2376.2.14.1 to 76.2.15.25476.2.15.255510
976.2.16.0/2376.2.16.1 to 76.2.17.25476.2.17.255510
1076.2.18.0/2376.2.18.1 to 76.2.19.25476.2.19.255510
1176.2.20.0/2376.2.20.1 to 76.2.21.25476.2.21.255510
1276.2.22.0/2376.2.22.1 to 76.2.23.25476.2.23.255510
1376.2.24.0/2376.2.24.1 to 76.2.25.25476.2.25.255510
1476.2.26.0/2376.2.26.1 to 76.2.27.25476.2.27.255510
1576.2.28.0/2376.2.28.1 to 76.2.29.25476.2.29.255510
1676.2.30.0/2376.2.30.1 to 76.2.31.25476.2.31.255510
1776.2.32.0/2376.2.32.1 to 76.2.33.25476.2.33.255510
1876.2.34.0/2376.2.34.1 to 76.2.35.25476.2.35.255510
1976.2.36.0/2376.2.36.1 to 76.2.37.25476.2.37.255510
2076.2.38.0/2376.2.38.1 to 76.2.39.25476.2.39.255510
2176.2.40.0/2376.2.40.1 to 76.2.41.25476.2.41.255510
2276.2.42.0/2376.2.42.1 to 76.2.43.25476.2.43.255510
2376.2.44.0/2376.2.44.1 to 76.2.45.25476.2.45.255510
2476.2.46.0/2376.2.46.1 to 76.2.47.25476.2.47.255510
2576.2.48.0/2376.2.48.1 to 76.2.49.25476.2.49.255510
2676.2.50.0/2376.2.50.1 to 76.2.51.25476.2.51.255510
2776.2.52.0/2376.2.52.1 to 76.2.53.25476.2.53.255510
2876.2.54.0/2376.2.54.1 to 76.2.55.25476.2.55.255510
2976.2.56.0/2376.2.56.1 to 76.2.57.25476.2.57.255510
3076.2.58.0/2376.2.58.1 to 76.2.59.25476.2.59.255510
3176.2.60.0/2376.2.60.1 to 76.2.61.25476.2.61.255510
3276.2.62.0/2376.2.62.1 to 76.2.63.25476.2.63.255510
3376.2.64.0/2376.2.64.1 to 76.2.65.25476.2.65.255510
3476.2.66.0/2376.2.66.1 to 76.2.67.25476.2.67.255510
3576.2.68.0/2376.2.68.1 to 76.2.69.25476.2.69.255510
3676.2.70.0/2376.2.70.1 to 76.2.71.25476.2.71.255510
3776.2.72.0/2376.2.72.1 to 76.2.73.25476.2.73.255510
3876.2.74.0/2376.2.74.1 to 76.2.75.25476.2.75.255510
3976.2.76.0/2376.2.76.1 to 76.2.77.25476.2.77.255510
4076.2.78.0/2376.2.78.1 to 76.2.79.25476.2.79.255510
4176.2.80.0/2376.2.80.1 to 76.2.81.25476.2.81.255510
4276.2.82.0/2376.2.82.1 to 76.2.83.25476.2.83.255510
4376.2.84.0/2376.2.84.1 to 76.2.85.25476.2.85.255510
4476.2.86.0/2376.2.86.1 to 76.2.87.25476.2.87.255510
4576.2.88.0/2376.2.88.1 to 76.2.89.25476.2.89.255510
4676.2.90.0/2376.2.90.1 to 76.2.91.25476.2.91.255510
4776.2.92.0/2376.2.92.1 to 76.2.93.25476.2.93.255510
4876.2.94.0/2376.2.94.1 to 76.2.95.25476.2.95.255510
4976.2.96.0/2376.2.96.1 to 76.2.97.25476.2.97.255510
5076.2.98.0/2376.2.98.1 to 76.2.99.25476.2.99.255510
5176.2.100.0/2376.2.100.1 to 76.2.101.25476.2.101.255510
5276.2.102.0/2376.2.102.1 to 76.2.103.25476.2.103.255510
5376.2.104.0/2376.2.104.1 to 76.2.105.25476.2.105.255510
5476.2.106.0/2376.2.106.1 to 76.2.107.25476.2.107.255510
5576.2.108.0/2376.2.108.1 to 76.2.109.25476.2.109.255510
5676.2.110.0/2376.2.110.1 to 76.2.111.25476.2.111.255510
5776.2.112.0/2376.2.112.1 to 76.2.113.25476.2.113.255510
5876.2.114.0/2376.2.114.1 to 76.2.115.25476.2.115.255510
5976.2.116.0/2376.2.116.1 to 76.2.117.25476.2.117.255510
6076.2.118.0/2376.2.118.1 to 76.2.119.25476.2.119.255510
6176.2.120.0/2376.2.120.1 to 76.2.121.25476.2.121.255510
6276.2.122.0/2376.2.122.1 to 76.2.123.25476.2.123.255510
6376.2.124.0/2376.2.124.1 to 76.2.125.25476.2.125.255510
6476.2.126.0/2376.2.126.1 to 76.2.127.25476.2.127.255510
6576.2.128.0/2376.2.128.1 to 76.2.129.25476.2.129.255510
6676.2.130.0/2376.2.130.1 to 76.2.131.25476.2.131.255510
6776.2.132.0/2376.2.132.1 to 76.2.133.25476.2.133.255510
6876.2.134.0/2376.2.134.1 to 76.2.135.25476.2.135.255510
6976.2.136.0/2376.2.136.1 to 76.2.137.25476.2.137.255510
7076.2.138.0/2376.2.138.1 to 76.2.139.25476.2.139.255510
7176.2.140.0/2376.2.140.1 to 76.2.141.25476.2.141.255510
7276.2.142.0/2376.2.142.1 to 76.2.143.25476.2.143.255510
7376.2.144.0/2376.2.144.1 to 76.2.145.25476.2.145.255510
7476.2.146.0/2376.2.146.1 to 76.2.147.25476.2.147.255510
7576.2.148.0/2376.2.148.1 to 76.2.149.25476.2.149.255510
7676.2.150.0/2376.2.150.1 to 76.2.151.25476.2.151.255510
7776.2.152.0/2376.2.152.1 to 76.2.153.25476.2.153.255510
7876.2.154.0/2376.2.154.1 to 76.2.155.25476.2.155.255510
7976.2.156.0/2376.2.156.1 to 76.2.157.25476.2.157.255510
8076.2.158.0/2376.2.158.1 to 76.2.159.25476.2.159.255510
8176.2.160.0/2376.2.160.1 to 76.2.161.25476.2.161.255510
8276.2.162.0/2376.2.162.1 to 76.2.163.25476.2.163.255510
8376.2.164.0/2376.2.164.1 to 76.2.165.25476.2.165.255510
8476.2.166.0/2376.2.166.1 to 76.2.167.25476.2.167.255510
8576.2.168.0/2376.2.168.1 to 76.2.169.25476.2.169.255510
8676.2.170.0/2376.2.170.1 to 76.2.171.25476.2.171.255510
8776.2.172.0/2376.2.172.1 to 76.2.173.25476.2.173.255510
8876.2.174.0/2376.2.174.1 to 76.2.175.25476.2.175.255510
8976.2.176.0/2376.2.176.1 to 76.2.177.25476.2.177.255510
9076.2.178.0/2376.2.178.1 to 76.2.179.25476.2.179.255510
9176.2.180.0/2376.2.180.1 to 76.2.181.25476.2.181.255510
9276.2.182.0/2376.2.182.1 to 76.2.183.25476.2.183.255510
9376.2.184.0/2376.2.184.1 to 76.2.185.25476.2.185.255510
9476.2.186.0/2376.2.186.1 to 76.2.187.25476.2.187.255510
9576.2.188.0/2376.2.188.1 to 76.2.189.25476.2.189.255510
9676.2.190.0/2376.2.190.1 to 76.2.191.25476.2.191.255510
9776.2.192.0/2376.2.192.1 to 76.2.193.25476.2.193.255510
9876.2.194.0/2376.2.194.1 to 76.2.195.25476.2.195.255510
9976.2.196.0/2376.2.196.1 to 76.2.197.25476.2.197.255510
10076.2.198.0/2376.2.198.1 to 76.2.199.25476.2.199.255510
10176.2.200.0/2376.2.200.1 to 76.2.201.25476.2.201.255510
10276.2.202.0/2376.2.202.1 to 76.2.203.25476.2.203.255510
10376.2.204.0/2376.2.204.1 to 76.2.205.25476.2.205.255510
10476.2.206.0/2376.2.206.1 to 76.2.207.25476.2.207.255510
10576.2.208.0/2376.2.208.1 to 76.2.209.25476.2.209.255510
10676.2.210.0/2376.2.210.1 to 76.2.211.25476.2.211.255510
10776.2.212.0/2376.2.212.1 to 76.2.213.25476.2.213.255510
10876.2.214.0/2376.2.214.1 to 76.2.215.25476.2.215.255510
10976.2.216.0/2376.2.216.1 to 76.2.217.25476.2.217.255510
11076.2.218.0/2376.2.218.1 to 76.2.219.25476.2.219.255510
11176.2.220.0/2376.2.220.1 to 76.2.221.25476.2.221.255510
11276.2.222.0/2376.2.222.1 to 76.2.223.25476.2.223.255510
11376.2.224.0/2376.2.224.1 to 76.2.225.25476.2.225.255510
11476.2.226.0/2376.2.226.1 to 76.2.227.25476.2.227.255510
11576.2.228.0/2376.2.228.1 to 76.2.229.25476.2.229.255510
11676.2.230.0/2376.2.230.1 to 76.2.231.25476.2.231.255510
11776.2.232.0/2376.2.232.1 to 76.2.233.25476.2.233.255510
11876.2.234.0/2376.2.234.1 to 76.2.235.25476.2.235.255510
11976.2.236.0/2376.2.236.1 to 76.2.237.25476.2.237.255510
12076.2.238.0/2376.2.238.1 to 76.2.239.25476.2.239.255510
12176.2.240.0/2376.2.240.1 to 76.2.241.25476.2.241.255510
12276.2.242.0/2376.2.242.1 to 76.2.243.25476.2.243.255510
12376.2.244.0/2376.2.244.1 to 76.2.245.25476.2.245.255510
12476.2.246.0/2376.2.246.1 to 76.2.247.25476.2.247.255510
12576.2.248.0/2376.2.248.1 to 76.2.249.25476.2.249.255510
12676.2.250.0/2376.2.250.1 to 76.2.251.25476.2.251.255510
12776.2.252.0/2376.2.252.1 to 76.2.253.25476.2.253.255510
12876.2.254.0/2376.2.254.1 to 76.2.255.25476.2.255.255510
12976.3.0.0/2376.3.0.1 to 76.3.1.25476.3.1.255510
13076.3.2.0/2376.3.2.1 to 76.3.3.25476.3.3.255510
13176.3.4.0/2376.3.4.1 to 76.3.5.25476.3.5.255510
13276.3.6.0/2376.3.6.1 to 76.3.7.25476.3.7.255510
13376.3.8.0/2376.3.8.1 to 76.3.9.25476.3.9.255510
13476.3.10.0/2376.3.10.1 to 76.3.11.25476.3.11.255510
13576.3.12.0/2376.3.12.1 to 76.3.13.25476.3.13.255510
13676.3.14.0/2376.3.14.1 to 76.3.15.25476.3.15.255510
13776.3.16.0/2376.3.16.1 to 76.3.17.25476.3.17.255510
13876.3.18.0/2376.3.18.1 to 76.3.19.25476.3.19.255510
13976.3.20.0/2376.3.20.1 to 76.3.21.25476.3.21.255510
14076.3.22.0/2376.3.22.1 to 76.3.23.25476.3.23.255510
14176.3.24.0/2376.3.24.1 to 76.3.25.25476.3.25.255510
14276.3.26.0/2376.3.26.1 to 76.3.27.25476.3.27.255510
14376.3.28.0/2376.3.28.1 to 76.3.29.25476.3.29.255510
14476.3.30.0/2376.3.30.1 to 76.3.31.25476.3.31.255510
14576.3.32.0/2376.3.32.1 to 76.3.33.25476.3.33.255510
14676.3.34.0/2376.3.34.1 to 76.3.35.25476.3.35.255510
14776.3.36.0/2376.3.36.1 to 76.3.37.25476.3.37.255510
14876.3.38.0/2376.3.38.1 to 76.3.39.25476.3.39.255510
14976.3.40.0/2376.3.40.1 to 76.3.41.25476.3.41.255510
15076.3.42.0/2376.3.42.1 to 76.3.43.25476.3.43.255510
15176.3.44.0/2376.3.44.1 to 76.3.45.25476.3.45.255510
15276.3.46.0/2376.3.46.1 to 76.3.47.25476.3.47.255510
15376.3.48.0/2376.3.48.1 to 76.3.49.25476.3.49.255510
15476.3.50.0/2376.3.50.1 to 76.3.51.25476.3.51.255510
15576.3.52.0/2376.3.52.1 to 76.3.53.25476.3.53.255510
15676.3.54.0/2376.3.54.1 to 76.3.55.25476.3.55.255510
15776.3.56.0/2376.3.56.1 to 76.3.57.25476.3.57.255510
15876.3.58.0/2376.3.58.1 to 76.3.59.25476.3.59.255510
15976.3.60.0/2376.3.60.1 to 76.3.61.25476.3.61.255510
16076.3.62.0/2376.3.62.1 to 76.3.63.25476.3.63.255510
16176.3.64.0/2376.3.64.1 to 76.3.65.25476.3.65.255510
16276.3.66.0/2376.3.66.1 to 76.3.67.25476.3.67.255510
16376.3.68.0/2376.3.68.1 to 76.3.69.25476.3.69.255510
16476.3.70.0/2376.3.70.1 to 76.3.71.25476.3.71.255510
16576.3.72.0/2376.3.72.1 to 76.3.73.25476.3.73.255510
16676.3.74.0/2376.3.74.1 to 76.3.75.25476.3.75.255510
16776.3.76.0/2376.3.76.1 to 76.3.77.25476.3.77.255510
16876.3.78.0/2376.3.78.1 to 76.3.79.25476.3.79.255510
16976.3.80.0/2376.3.80.1 to 76.3.81.25476.3.81.255510
17076.3.82.0/2376.3.82.1 to 76.3.83.25476.3.83.255510
17176.3.84.0/2376.3.84.1 to 76.3.85.25476.3.85.255510
17276.3.86.0/2376.3.86.1 to 76.3.87.25476.3.87.255510
17376.3.88.0/2376.3.88.1 to 76.3.89.25476.3.89.255510
17476.3.90.0/2376.3.90.1 to 76.3.91.25476.3.91.255510
17576.3.92.0/2376.3.92.1 to 76.3.93.25476.3.93.255510
17676.3.94.0/2376.3.94.1 to 76.3.95.25476.3.95.255510
17776.3.96.0/2376.3.96.1 to 76.3.97.25476.3.97.255510
17876.3.98.0/2376.3.98.1 to 76.3.99.25476.3.99.255510
17976.3.100.0/2376.3.100.1 to 76.3.101.25476.3.101.255510
18076.3.102.0/2376.3.102.1 to 76.3.103.25476.3.103.255510
18176.3.104.0/2376.3.104.1 to 76.3.105.25476.3.105.255510
18276.3.106.0/2376.3.106.1 to 76.3.107.25476.3.107.255510
18376.3.108.0/2376.3.108.1 to 76.3.109.25476.3.109.255510
18476.3.110.0/2376.3.110.1 to 76.3.111.25476.3.111.255510
18576.3.112.0/2376.3.112.1 to 76.3.113.25476.3.113.255510
18676.3.114.0/2376.3.114.1 to 76.3.115.25476.3.115.255510
18776.3.116.0/2376.3.116.1 to 76.3.117.25476.3.117.255510
18876.3.118.0/2376.3.118.1 to 76.3.119.25476.3.119.255510
18976.3.120.0/2376.3.120.1 to 76.3.121.25476.3.121.255510
19076.3.122.0/2376.3.122.1 to 76.3.123.25476.3.123.255510
19176.3.124.0/2376.3.124.1 to 76.3.125.25476.3.125.255510
19276.3.126.0/2376.3.126.1 to 76.3.127.25476.3.127.255510
19376.3.128.0/2376.3.128.1 to 76.3.129.25476.3.129.255510
19476.3.130.0/2376.3.130.1 to 76.3.131.25476.3.131.255510
19576.3.132.0/2376.3.132.1 to 76.3.133.25476.3.133.255510
19676.3.134.0/2376.3.134.1 to 76.3.135.25476.3.135.255510
19776.3.136.0/2376.3.136.1 to 76.3.137.25476.3.137.255510
19876.3.138.0/2376.3.138.1 to 76.3.139.25476.3.139.255510
19976.3.140.0/2376.3.140.1 to 76.3.141.25476.3.141.255510
20076.3.142.0/2376.3.142.1 to 76.3.143.25476.3.143.255510
20176.3.144.0/2376.3.144.1 to 76.3.145.25476.3.145.255510
20276.3.146.0/2376.3.146.1 to 76.3.147.25476.3.147.255510
20376.3.148.0/2376.3.148.1 to 76.3.149.25476.3.149.255510
20476.3.150.0/2376.3.150.1 to 76.3.151.25476.3.151.255510
20576.3.152.0/2376.3.152.1 to 76.3.153.25476.3.153.255510
20676.3.154.0/2376.3.154.1 to 76.3.155.25476.3.155.255510
20776.3.156.0/2376.3.156.1 to 76.3.157.25476.3.157.255510
20876.3.158.0/2376.3.158.1 to 76.3.159.25476.3.159.255510
20976.3.160.0/2376.3.160.1 to 76.3.161.25476.3.161.255510
21076.3.162.0/2376.3.162.1 to 76.3.163.25476.3.163.255510
21176.3.164.0/2376.3.164.1 to 76.3.165.25476.3.165.255510
21276.3.166.0/2376.3.166.1 to 76.3.167.25476.3.167.255510
21376.3.168.0/2376.3.168.1 to 76.3.169.25476.3.169.255510
21476.3.170.0/2376.3.170.1 to 76.3.171.25476.3.171.255510
21576.3.172.0/2376.3.172.1 to 76.3.173.25476.3.173.255510
21676.3.174.0/2376.3.174.1 to 76.3.175.25476.3.175.255510
21776.3.176.0/2376.3.176.1 to 76.3.177.25476.3.177.255510
21876.3.178.0/2376.3.178.1 to 76.3.179.25476.3.179.255510
21976.3.180.0/2376.3.180.1 to 76.3.181.25476.3.181.255510
22076.3.182.0/2376.3.182.1 to 76.3.183.25476.3.183.255510
22176.3.184.0/2376.3.184.1 to 76.3.185.25476.3.185.255510
22276.3.186.0/2376.3.186.1 to 76.3.187.25476.3.187.255510
22376.3.188.0/2376.3.188.1 to 76.3.189.25476.3.189.255510
22476.3.190.0/2376.3.190.1 to 76.3.191.25476.3.191.255510
22576.3.192.0/2376.3.192.1 to 76.3.193.25476.3.193.255510
22676.3.194.0/2376.3.194.1 to 76.3.195.25476.3.195.255510
22776.3.196.0/2376.3.196.1 to 76.3.197.25476.3.197.255510
22876.3.198.0/2376.3.198.1 to 76.3.199.25476.3.199.255510
22976.3.200.0/2376.3.200.1 to 76.3.201.25476.3.201.255510
23076.3.202.0/2376.3.202.1 to 76.3.203.25476.3.203.255510
23176.3.204.0/2376.3.204.1 to 76.3.205.25476.3.205.255510
23276.3.206.0/2376.3.206.1 to 76.3.207.25476.3.207.255510
23376.3.208.0/2376.3.208.1 to 76.3.209.25476.3.209.255510
23476.3.210.0/2376.3.210.1 to 76.3.211.25476.3.211.255510
23576.3.212.0/2376.3.212.1 to 76.3.213.25476.3.213.255510
23676.3.214.0/2376.3.214.1 to 76.3.215.25476.3.215.255510
23776.3.216.0/2376.3.216.1 to 76.3.217.25476.3.217.255510
23876.3.218.0/2376.3.218.1 to 76.3.219.25476.3.219.255510
23976.3.220.0/2376.3.220.1 to 76.3.221.25476.3.221.255510
24076.3.222.0/2376.3.222.1 to 76.3.223.25476.3.223.255510
24176.3.224.0/2376.3.224.1 to 76.3.225.25476.3.225.255510
24276.3.226.0/2376.3.226.1 to 76.3.227.25476.3.227.255510
24376.3.228.0/2376.3.228.1 to 76.3.229.25476.3.229.255510
24476.3.230.0/2376.3.230.1 to 76.3.231.25476.3.231.255510
24576.3.232.0/2376.3.232.1 to 76.3.233.25476.3.233.255510
24676.3.234.0/2376.3.234.1 to 76.3.235.25476.3.235.255510
24776.3.236.0/2376.3.236.1 to 76.3.237.25476.3.237.255510
24876.3.238.0/2376.3.238.1 to 76.3.239.25476.3.239.255510
24976.3.240.0/2376.3.240.1 to 76.3.241.25476.3.241.255510
25076.3.242.0/2376.3.242.1 to 76.3.243.25476.3.243.255510
25176.3.244.0/2376.3.244.1 to 76.3.245.25476.3.245.255510
25276.3.246.0/2376.3.246.1 to 76.3.247.25476.3.247.255510
25376.3.248.0/2376.3.248.1 to 76.3.249.25476.3.249.255510
25476.3.250.0/2376.3.250.1 to 76.3.251.25476.3.251.255510
25576.3.252.0/2376.3.252.1 to 76.3.253.25476.3.253.255510
25676.3.254.0/2376.3.254.1 to 76.3.255.25476.3.255.255510

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.