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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.

Network47.44.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
47.44.0.0
Broadcast address
47.45.255.255
First usable
47.44.0.1
Last usable
47.45.255.254
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 2F2C0000 · Integer 791412736 to 791543807
Reverse DNS zones
44.47.in-addr.arpa
45.47.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
Address00101111.00101100.00000000.0000000047.44.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network00101111.00101100.00000000.0000000047.44.0.0
Broadcast00101111.00101101.11111111.1111111147.45.255.255
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)

47.44.0.0/15 makes 256 subnets of /23.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
147.44.0.0/2347.44.0.1 to 47.44.1.25447.44.1.255510
247.44.2.0/2347.44.2.1 to 47.44.3.25447.44.3.255510
347.44.4.0/2347.44.4.1 to 47.44.5.25447.44.5.255510
447.44.6.0/2347.44.6.1 to 47.44.7.25447.44.7.255510
547.44.8.0/2347.44.8.1 to 47.44.9.25447.44.9.255510
647.44.10.0/2347.44.10.1 to 47.44.11.25447.44.11.255510
747.44.12.0/2347.44.12.1 to 47.44.13.25447.44.13.255510
847.44.14.0/2347.44.14.1 to 47.44.15.25447.44.15.255510
947.44.16.0/2347.44.16.1 to 47.44.17.25447.44.17.255510
1047.44.18.0/2347.44.18.1 to 47.44.19.25447.44.19.255510
1147.44.20.0/2347.44.20.1 to 47.44.21.25447.44.21.255510
1247.44.22.0/2347.44.22.1 to 47.44.23.25447.44.23.255510
1347.44.24.0/2347.44.24.1 to 47.44.25.25447.44.25.255510
1447.44.26.0/2347.44.26.1 to 47.44.27.25447.44.27.255510
1547.44.28.0/2347.44.28.1 to 47.44.29.25447.44.29.255510
1647.44.30.0/2347.44.30.1 to 47.44.31.25447.44.31.255510
1747.44.32.0/2347.44.32.1 to 47.44.33.25447.44.33.255510
1847.44.34.0/2347.44.34.1 to 47.44.35.25447.44.35.255510
1947.44.36.0/2347.44.36.1 to 47.44.37.25447.44.37.255510
2047.44.38.0/2347.44.38.1 to 47.44.39.25447.44.39.255510
2147.44.40.0/2347.44.40.1 to 47.44.41.25447.44.41.255510
2247.44.42.0/2347.44.42.1 to 47.44.43.25447.44.43.255510
2347.44.44.0/2347.44.44.1 to 47.44.45.25447.44.45.255510
2447.44.46.0/2347.44.46.1 to 47.44.47.25447.44.47.255510
2547.44.48.0/2347.44.48.1 to 47.44.49.25447.44.49.255510
2647.44.50.0/2347.44.50.1 to 47.44.51.25447.44.51.255510
2747.44.52.0/2347.44.52.1 to 47.44.53.25447.44.53.255510
2847.44.54.0/2347.44.54.1 to 47.44.55.25447.44.55.255510
2947.44.56.0/2347.44.56.1 to 47.44.57.25447.44.57.255510
3047.44.58.0/2347.44.58.1 to 47.44.59.25447.44.59.255510
3147.44.60.0/2347.44.60.1 to 47.44.61.25447.44.61.255510
3247.44.62.0/2347.44.62.1 to 47.44.63.25447.44.63.255510
3347.44.64.0/2347.44.64.1 to 47.44.65.25447.44.65.255510
3447.44.66.0/2347.44.66.1 to 47.44.67.25447.44.67.255510
3547.44.68.0/2347.44.68.1 to 47.44.69.25447.44.69.255510
3647.44.70.0/2347.44.70.1 to 47.44.71.25447.44.71.255510
3747.44.72.0/2347.44.72.1 to 47.44.73.25447.44.73.255510
3847.44.74.0/2347.44.74.1 to 47.44.75.25447.44.75.255510
3947.44.76.0/2347.44.76.1 to 47.44.77.25447.44.77.255510
4047.44.78.0/2347.44.78.1 to 47.44.79.25447.44.79.255510
4147.44.80.0/2347.44.80.1 to 47.44.81.25447.44.81.255510
4247.44.82.0/2347.44.82.1 to 47.44.83.25447.44.83.255510
4347.44.84.0/2347.44.84.1 to 47.44.85.25447.44.85.255510
4447.44.86.0/2347.44.86.1 to 47.44.87.25447.44.87.255510
4547.44.88.0/2347.44.88.1 to 47.44.89.25447.44.89.255510
4647.44.90.0/2347.44.90.1 to 47.44.91.25447.44.91.255510
4747.44.92.0/2347.44.92.1 to 47.44.93.25447.44.93.255510
4847.44.94.0/2347.44.94.1 to 47.44.95.25447.44.95.255510
4947.44.96.0/2347.44.96.1 to 47.44.97.25447.44.97.255510
5047.44.98.0/2347.44.98.1 to 47.44.99.25447.44.99.255510
5147.44.100.0/2347.44.100.1 to 47.44.101.25447.44.101.255510
5247.44.102.0/2347.44.102.1 to 47.44.103.25447.44.103.255510
5347.44.104.0/2347.44.104.1 to 47.44.105.25447.44.105.255510
5447.44.106.0/2347.44.106.1 to 47.44.107.25447.44.107.255510
5547.44.108.0/2347.44.108.1 to 47.44.109.25447.44.109.255510
5647.44.110.0/2347.44.110.1 to 47.44.111.25447.44.111.255510
5747.44.112.0/2347.44.112.1 to 47.44.113.25447.44.113.255510
5847.44.114.0/2347.44.114.1 to 47.44.115.25447.44.115.255510
5947.44.116.0/2347.44.116.1 to 47.44.117.25447.44.117.255510
6047.44.118.0/2347.44.118.1 to 47.44.119.25447.44.119.255510
6147.44.120.0/2347.44.120.1 to 47.44.121.25447.44.121.255510
6247.44.122.0/2347.44.122.1 to 47.44.123.25447.44.123.255510
6347.44.124.0/2347.44.124.1 to 47.44.125.25447.44.125.255510
6447.44.126.0/2347.44.126.1 to 47.44.127.25447.44.127.255510
6547.44.128.0/2347.44.128.1 to 47.44.129.25447.44.129.255510
6647.44.130.0/2347.44.130.1 to 47.44.131.25447.44.131.255510
6747.44.132.0/2347.44.132.1 to 47.44.133.25447.44.133.255510
6847.44.134.0/2347.44.134.1 to 47.44.135.25447.44.135.255510
6947.44.136.0/2347.44.136.1 to 47.44.137.25447.44.137.255510
7047.44.138.0/2347.44.138.1 to 47.44.139.25447.44.139.255510
7147.44.140.0/2347.44.140.1 to 47.44.141.25447.44.141.255510
7247.44.142.0/2347.44.142.1 to 47.44.143.25447.44.143.255510
7347.44.144.0/2347.44.144.1 to 47.44.145.25447.44.145.255510
7447.44.146.0/2347.44.146.1 to 47.44.147.25447.44.147.255510
7547.44.148.0/2347.44.148.1 to 47.44.149.25447.44.149.255510
7647.44.150.0/2347.44.150.1 to 47.44.151.25447.44.151.255510
7747.44.152.0/2347.44.152.1 to 47.44.153.25447.44.153.255510
7847.44.154.0/2347.44.154.1 to 47.44.155.25447.44.155.255510
7947.44.156.0/2347.44.156.1 to 47.44.157.25447.44.157.255510
8047.44.158.0/2347.44.158.1 to 47.44.159.25447.44.159.255510
8147.44.160.0/2347.44.160.1 to 47.44.161.25447.44.161.255510
8247.44.162.0/2347.44.162.1 to 47.44.163.25447.44.163.255510
8347.44.164.0/2347.44.164.1 to 47.44.165.25447.44.165.255510
8447.44.166.0/2347.44.166.1 to 47.44.167.25447.44.167.255510
8547.44.168.0/2347.44.168.1 to 47.44.169.25447.44.169.255510
8647.44.170.0/2347.44.170.1 to 47.44.171.25447.44.171.255510
8747.44.172.0/2347.44.172.1 to 47.44.173.25447.44.173.255510
8847.44.174.0/2347.44.174.1 to 47.44.175.25447.44.175.255510
8947.44.176.0/2347.44.176.1 to 47.44.177.25447.44.177.255510
9047.44.178.0/2347.44.178.1 to 47.44.179.25447.44.179.255510
9147.44.180.0/2347.44.180.1 to 47.44.181.25447.44.181.255510
9247.44.182.0/2347.44.182.1 to 47.44.183.25447.44.183.255510
9347.44.184.0/2347.44.184.1 to 47.44.185.25447.44.185.255510
9447.44.186.0/2347.44.186.1 to 47.44.187.25447.44.187.255510
9547.44.188.0/2347.44.188.1 to 47.44.189.25447.44.189.255510
9647.44.190.0/2347.44.190.1 to 47.44.191.25447.44.191.255510
9747.44.192.0/2347.44.192.1 to 47.44.193.25447.44.193.255510
9847.44.194.0/2347.44.194.1 to 47.44.195.25447.44.195.255510
9947.44.196.0/2347.44.196.1 to 47.44.197.25447.44.197.255510
10047.44.198.0/2347.44.198.1 to 47.44.199.25447.44.199.255510
10147.44.200.0/2347.44.200.1 to 47.44.201.25447.44.201.255510
10247.44.202.0/2347.44.202.1 to 47.44.203.25447.44.203.255510
10347.44.204.0/2347.44.204.1 to 47.44.205.25447.44.205.255510
10447.44.206.0/2347.44.206.1 to 47.44.207.25447.44.207.255510
10547.44.208.0/2347.44.208.1 to 47.44.209.25447.44.209.255510
10647.44.210.0/2347.44.210.1 to 47.44.211.25447.44.211.255510
10747.44.212.0/2347.44.212.1 to 47.44.213.25447.44.213.255510
10847.44.214.0/2347.44.214.1 to 47.44.215.25447.44.215.255510
10947.44.216.0/2347.44.216.1 to 47.44.217.25447.44.217.255510
11047.44.218.0/2347.44.218.1 to 47.44.219.25447.44.219.255510
11147.44.220.0/2347.44.220.1 to 47.44.221.25447.44.221.255510
11247.44.222.0/2347.44.222.1 to 47.44.223.25447.44.223.255510
11347.44.224.0/2347.44.224.1 to 47.44.225.25447.44.225.255510
11447.44.226.0/2347.44.226.1 to 47.44.227.25447.44.227.255510
11547.44.228.0/2347.44.228.1 to 47.44.229.25447.44.229.255510
11647.44.230.0/2347.44.230.1 to 47.44.231.25447.44.231.255510
11747.44.232.0/2347.44.232.1 to 47.44.233.25447.44.233.255510
11847.44.234.0/2347.44.234.1 to 47.44.235.25447.44.235.255510
11947.44.236.0/2347.44.236.1 to 47.44.237.25447.44.237.255510
12047.44.238.0/2347.44.238.1 to 47.44.239.25447.44.239.255510
12147.44.240.0/2347.44.240.1 to 47.44.241.25447.44.241.255510
12247.44.242.0/2347.44.242.1 to 47.44.243.25447.44.243.255510
12347.44.244.0/2347.44.244.1 to 47.44.245.25447.44.245.255510
12447.44.246.0/2347.44.246.1 to 47.44.247.25447.44.247.255510
12547.44.248.0/2347.44.248.1 to 47.44.249.25447.44.249.255510
12647.44.250.0/2347.44.250.1 to 47.44.251.25447.44.251.255510
12747.44.252.0/2347.44.252.1 to 47.44.253.25447.44.253.255510
12847.44.254.0/2347.44.254.1 to 47.44.255.25447.44.255.255510
12947.45.0.0/2347.45.0.1 to 47.45.1.25447.45.1.255510
13047.45.2.0/2347.45.2.1 to 47.45.3.25447.45.3.255510
13147.45.4.0/2347.45.4.1 to 47.45.5.25447.45.5.255510
13247.45.6.0/2347.45.6.1 to 47.45.7.25447.45.7.255510
13347.45.8.0/2347.45.8.1 to 47.45.9.25447.45.9.255510
13447.45.10.0/2347.45.10.1 to 47.45.11.25447.45.11.255510
13547.45.12.0/2347.45.12.1 to 47.45.13.25447.45.13.255510
13647.45.14.0/2347.45.14.1 to 47.45.15.25447.45.15.255510
13747.45.16.0/2347.45.16.1 to 47.45.17.25447.45.17.255510
13847.45.18.0/2347.45.18.1 to 47.45.19.25447.45.19.255510
13947.45.20.0/2347.45.20.1 to 47.45.21.25447.45.21.255510
14047.45.22.0/2347.45.22.1 to 47.45.23.25447.45.23.255510
14147.45.24.0/2347.45.24.1 to 47.45.25.25447.45.25.255510
14247.45.26.0/2347.45.26.1 to 47.45.27.25447.45.27.255510
14347.45.28.0/2347.45.28.1 to 47.45.29.25447.45.29.255510
14447.45.30.0/2347.45.30.1 to 47.45.31.25447.45.31.255510
14547.45.32.0/2347.45.32.1 to 47.45.33.25447.45.33.255510
14647.45.34.0/2347.45.34.1 to 47.45.35.25447.45.35.255510
14747.45.36.0/2347.45.36.1 to 47.45.37.25447.45.37.255510
14847.45.38.0/2347.45.38.1 to 47.45.39.25447.45.39.255510
14947.45.40.0/2347.45.40.1 to 47.45.41.25447.45.41.255510
15047.45.42.0/2347.45.42.1 to 47.45.43.25447.45.43.255510
15147.45.44.0/2347.45.44.1 to 47.45.45.25447.45.45.255510
15247.45.46.0/2347.45.46.1 to 47.45.47.25447.45.47.255510
15347.45.48.0/2347.45.48.1 to 47.45.49.25447.45.49.255510
15447.45.50.0/2347.45.50.1 to 47.45.51.25447.45.51.255510
15547.45.52.0/2347.45.52.1 to 47.45.53.25447.45.53.255510
15647.45.54.0/2347.45.54.1 to 47.45.55.25447.45.55.255510
15747.45.56.0/2347.45.56.1 to 47.45.57.25447.45.57.255510
15847.45.58.0/2347.45.58.1 to 47.45.59.25447.45.59.255510
15947.45.60.0/2347.45.60.1 to 47.45.61.25447.45.61.255510
16047.45.62.0/2347.45.62.1 to 47.45.63.25447.45.63.255510
16147.45.64.0/2347.45.64.1 to 47.45.65.25447.45.65.255510
16247.45.66.0/2347.45.66.1 to 47.45.67.25447.45.67.255510
16347.45.68.0/2347.45.68.1 to 47.45.69.25447.45.69.255510
16447.45.70.0/2347.45.70.1 to 47.45.71.25447.45.71.255510
16547.45.72.0/2347.45.72.1 to 47.45.73.25447.45.73.255510
16647.45.74.0/2347.45.74.1 to 47.45.75.25447.45.75.255510
16747.45.76.0/2347.45.76.1 to 47.45.77.25447.45.77.255510
16847.45.78.0/2347.45.78.1 to 47.45.79.25447.45.79.255510
16947.45.80.0/2347.45.80.1 to 47.45.81.25447.45.81.255510
17047.45.82.0/2347.45.82.1 to 47.45.83.25447.45.83.255510
17147.45.84.0/2347.45.84.1 to 47.45.85.25447.45.85.255510
17247.45.86.0/2347.45.86.1 to 47.45.87.25447.45.87.255510
17347.45.88.0/2347.45.88.1 to 47.45.89.25447.45.89.255510
17447.45.90.0/2347.45.90.1 to 47.45.91.25447.45.91.255510
17547.45.92.0/2347.45.92.1 to 47.45.93.25447.45.93.255510
17647.45.94.0/2347.45.94.1 to 47.45.95.25447.45.95.255510
17747.45.96.0/2347.45.96.1 to 47.45.97.25447.45.97.255510
17847.45.98.0/2347.45.98.1 to 47.45.99.25447.45.99.255510
17947.45.100.0/2347.45.100.1 to 47.45.101.25447.45.101.255510
18047.45.102.0/2347.45.102.1 to 47.45.103.25447.45.103.255510
18147.45.104.0/2347.45.104.1 to 47.45.105.25447.45.105.255510
18247.45.106.0/2347.45.106.1 to 47.45.107.25447.45.107.255510
18347.45.108.0/2347.45.108.1 to 47.45.109.25447.45.109.255510
18447.45.110.0/2347.45.110.1 to 47.45.111.25447.45.111.255510
18547.45.112.0/2347.45.112.1 to 47.45.113.25447.45.113.255510
18647.45.114.0/2347.45.114.1 to 47.45.115.25447.45.115.255510
18747.45.116.0/2347.45.116.1 to 47.45.117.25447.45.117.255510
18847.45.118.0/2347.45.118.1 to 47.45.119.25447.45.119.255510
18947.45.120.0/2347.45.120.1 to 47.45.121.25447.45.121.255510
19047.45.122.0/2347.45.122.1 to 47.45.123.25447.45.123.255510
19147.45.124.0/2347.45.124.1 to 47.45.125.25447.45.125.255510
19247.45.126.0/2347.45.126.1 to 47.45.127.25447.45.127.255510
19347.45.128.0/2347.45.128.1 to 47.45.129.25447.45.129.255510
19447.45.130.0/2347.45.130.1 to 47.45.131.25447.45.131.255510
19547.45.132.0/2347.45.132.1 to 47.45.133.25447.45.133.255510
19647.45.134.0/2347.45.134.1 to 47.45.135.25447.45.135.255510
19747.45.136.0/2347.45.136.1 to 47.45.137.25447.45.137.255510
19847.45.138.0/2347.45.138.1 to 47.45.139.25447.45.139.255510
19947.45.140.0/2347.45.140.1 to 47.45.141.25447.45.141.255510
20047.45.142.0/2347.45.142.1 to 47.45.143.25447.45.143.255510
20147.45.144.0/2347.45.144.1 to 47.45.145.25447.45.145.255510
20247.45.146.0/2347.45.146.1 to 47.45.147.25447.45.147.255510
20347.45.148.0/2347.45.148.1 to 47.45.149.25447.45.149.255510
20447.45.150.0/2347.45.150.1 to 47.45.151.25447.45.151.255510
20547.45.152.0/2347.45.152.1 to 47.45.153.25447.45.153.255510
20647.45.154.0/2347.45.154.1 to 47.45.155.25447.45.155.255510
20747.45.156.0/2347.45.156.1 to 47.45.157.25447.45.157.255510
20847.45.158.0/2347.45.158.1 to 47.45.159.25447.45.159.255510
20947.45.160.0/2347.45.160.1 to 47.45.161.25447.45.161.255510
21047.45.162.0/2347.45.162.1 to 47.45.163.25447.45.163.255510
21147.45.164.0/2347.45.164.1 to 47.45.165.25447.45.165.255510
21247.45.166.0/2347.45.166.1 to 47.45.167.25447.45.167.255510
21347.45.168.0/2347.45.168.1 to 47.45.169.25447.45.169.255510
21447.45.170.0/2347.45.170.1 to 47.45.171.25447.45.171.255510
21547.45.172.0/2347.45.172.1 to 47.45.173.25447.45.173.255510
21647.45.174.0/2347.45.174.1 to 47.45.175.25447.45.175.255510
21747.45.176.0/2347.45.176.1 to 47.45.177.25447.45.177.255510
21847.45.178.0/2347.45.178.1 to 47.45.179.25447.45.179.255510
21947.45.180.0/2347.45.180.1 to 47.45.181.25447.45.181.255510
22047.45.182.0/2347.45.182.1 to 47.45.183.25447.45.183.255510
22147.45.184.0/2347.45.184.1 to 47.45.185.25447.45.185.255510
22247.45.186.0/2347.45.186.1 to 47.45.187.25447.45.187.255510
22347.45.188.0/2347.45.188.1 to 47.45.189.25447.45.189.255510
22447.45.190.0/2347.45.190.1 to 47.45.191.25447.45.191.255510
22547.45.192.0/2347.45.192.1 to 47.45.193.25447.45.193.255510
22647.45.194.0/2347.45.194.1 to 47.45.195.25447.45.195.255510
22747.45.196.0/2347.45.196.1 to 47.45.197.25447.45.197.255510
22847.45.198.0/2347.45.198.1 to 47.45.199.25447.45.199.255510
22947.45.200.0/2347.45.200.1 to 47.45.201.25447.45.201.255510
23047.45.202.0/2347.45.202.1 to 47.45.203.25447.45.203.255510
23147.45.204.0/2347.45.204.1 to 47.45.205.25447.45.205.255510
23247.45.206.0/2347.45.206.1 to 47.45.207.25447.45.207.255510
23347.45.208.0/2347.45.208.1 to 47.45.209.25447.45.209.255510
23447.45.210.0/2347.45.210.1 to 47.45.211.25447.45.211.255510
23547.45.212.0/2347.45.212.1 to 47.45.213.25447.45.213.255510
23647.45.214.0/2347.45.214.1 to 47.45.215.25447.45.215.255510
23747.45.216.0/2347.45.216.1 to 47.45.217.25447.45.217.255510
23847.45.218.0/2347.45.218.1 to 47.45.219.25447.45.219.255510
23947.45.220.0/2347.45.220.1 to 47.45.221.25447.45.221.255510
24047.45.222.0/2347.45.222.1 to 47.45.223.25447.45.223.255510
24147.45.224.0/2347.45.224.1 to 47.45.225.25447.45.225.255510
24247.45.226.0/2347.45.226.1 to 47.45.227.25447.45.227.255510
24347.45.228.0/2347.45.228.1 to 47.45.229.25447.45.229.255510
24447.45.230.0/2347.45.230.1 to 47.45.231.25447.45.231.255510
24547.45.232.0/2347.45.232.1 to 47.45.233.25447.45.233.255510
24647.45.234.0/2347.45.234.1 to 47.45.235.25447.45.235.255510
24747.45.236.0/2347.45.236.1 to 47.45.237.25447.45.237.255510
24847.45.238.0/2347.45.238.1 to 47.45.239.25447.45.239.255510
24947.45.240.0/2347.45.240.1 to 47.45.241.25447.45.241.255510
25047.45.242.0/2347.45.242.1 to 47.45.243.25447.45.243.255510
25147.45.244.0/2347.45.244.1 to 47.45.245.25447.45.245.255510
25247.45.246.0/2347.45.246.1 to 47.45.247.25447.45.247.255510
25347.45.248.0/2347.45.248.1 to 47.45.249.25447.45.249.255510
25447.45.250.0/2347.45.250.1 to 47.45.251.25447.45.251.255510
25547.45.252.0/2347.45.252.1 to 47.45.253.25447.45.253.255510
25647.45.254.0/2347.45.254.1 to 47.45.255.25447.45.255.255510

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.