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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.

Network47.0.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
47.0.0.0
Broadcast address
47.63.255.255
First usable
47.0.0.1
Last usable
47.63.255.254
Usable hosts
4,194,302 (4,194,304 less the network and broadcast addresses)
Subnet mask
255.192.0.0
Wildcard mask
0.63.255.255 (Cisco ACLs, OSPF)
Prefix length
/10
Type
Public public
Old class
A (default /8)
As numbers
Hex 2F000000 · Integer 788529152 to 792723455
Reverse DNS zones
0.47.in-addr.arpa
1.47.in-addr.arpa
2.47.in-addr.arpa
3.47.in-addr.arpa
4.47.in-addr.arpa
5.47.in-addr.arpa
6.47.in-addr.arpa
7.47.in-addr.arpa
8.47.in-addr.arpa
9.47.in-addr.arpa
10.47.in-addr.arpa
11.47.in-addr.arpa
12.47.in-addr.arpa
13.47.in-addr.arpa
14.47.in-addr.arpa
15.47.in-addr.arpa
and 48 more
/10 is not on a 8-bit boundary, so it takes 64 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00101111.00000000.00000000.0000000047.0.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network00101111.00000000.00000000.0000000047.0.0.0
Broadcast00101111.00111111.11111111.1111111147.63.255.255
Split into smaller subnets/22
/11 (2)/12 (4)/13 (8)/14 (16)/15 (32)/16 (64)/17 (128)/18 (256)/19 (512)/20 (1,024)/21 (2,048)/22 (4,096)

47.0.0.0/10 makes 4,096 subnets of /22; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
147.0.0.0/2247.0.0.1 to 47.0.3.25447.0.3.2551,022
247.0.4.0/2247.0.4.1 to 47.0.7.25447.0.7.2551,022
347.0.8.0/2247.0.8.1 to 47.0.11.25447.0.11.2551,022
447.0.12.0/2247.0.12.1 to 47.0.15.25447.0.15.2551,022
547.0.16.0/2247.0.16.1 to 47.0.19.25447.0.19.2551,022
647.0.20.0/2247.0.20.1 to 47.0.23.25447.0.23.2551,022
747.0.24.0/2247.0.24.1 to 47.0.27.25447.0.27.2551,022
847.0.28.0/2247.0.28.1 to 47.0.31.25447.0.31.2551,022
947.0.32.0/2247.0.32.1 to 47.0.35.25447.0.35.2551,022
1047.0.36.0/2247.0.36.1 to 47.0.39.25447.0.39.2551,022
1147.0.40.0/2247.0.40.1 to 47.0.43.25447.0.43.2551,022
1247.0.44.0/2247.0.44.1 to 47.0.47.25447.0.47.2551,022
1347.0.48.0/2247.0.48.1 to 47.0.51.25447.0.51.2551,022
1447.0.52.0/2247.0.52.1 to 47.0.55.25447.0.55.2551,022
1547.0.56.0/2247.0.56.1 to 47.0.59.25447.0.59.2551,022
1647.0.60.0/2247.0.60.1 to 47.0.63.25447.0.63.2551,022
1747.0.64.0/2247.0.64.1 to 47.0.67.25447.0.67.2551,022
1847.0.68.0/2247.0.68.1 to 47.0.71.25447.0.71.2551,022
1947.0.72.0/2247.0.72.1 to 47.0.75.25447.0.75.2551,022
2047.0.76.0/2247.0.76.1 to 47.0.79.25447.0.79.2551,022
2147.0.80.0/2247.0.80.1 to 47.0.83.25447.0.83.2551,022
2247.0.84.0/2247.0.84.1 to 47.0.87.25447.0.87.2551,022
2347.0.88.0/2247.0.88.1 to 47.0.91.25447.0.91.2551,022
2447.0.92.0/2247.0.92.1 to 47.0.95.25447.0.95.2551,022
2547.0.96.0/2247.0.96.1 to 47.0.99.25447.0.99.2551,022
2647.0.100.0/2247.0.100.1 to 47.0.103.25447.0.103.2551,022
2747.0.104.0/2247.0.104.1 to 47.0.107.25447.0.107.2551,022
2847.0.108.0/2247.0.108.1 to 47.0.111.25447.0.111.2551,022
2947.0.112.0/2247.0.112.1 to 47.0.115.25447.0.115.2551,022
3047.0.116.0/2247.0.116.1 to 47.0.119.25447.0.119.2551,022
3147.0.120.0/2247.0.120.1 to 47.0.123.25447.0.123.2551,022
3247.0.124.0/2247.0.124.1 to 47.0.127.25447.0.127.2551,022
3347.0.128.0/2247.0.128.1 to 47.0.131.25447.0.131.2551,022
3447.0.132.0/2247.0.132.1 to 47.0.135.25447.0.135.2551,022
3547.0.136.0/2247.0.136.1 to 47.0.139.25447.0.139.2551,022
3647.0.140.0/2247.0.140.1 to 47.0.143.25447.0.143.2551,022
3747.0.144.0/2247.0.144.1 to 47.0.147.25447.0.147.2551,022
3847.0.148.0/2247.0.148.1 to 47.0.151.25447.0.151.2551,022
3947.0.152.0/2247.0.152.1 to 47.0.155.25447.0.155.2551,022
4047.0.156.0/2247.0.156.1 to 47.0.159.25447.0.159.2551,022
4147.0.160.0/2247.0.160.1 to 47.0.163.25447.0.163.2551,022
4247.0.164.0/2247.0.164.1 to 47.0.167.25447.0.167.2551,022
4347.0.168.0/2247.0.168.1 to 47.0.171.25447.0.171.2551,022
4447.0.172.0/2247.0.172.1 to 47.0.175.25447.0.175.2551,022
4547.0.176.0/2247.0.176.1 to 47.0.179.25447.0.179.2551,022
4647.0.180.0/2247.0.180.1 to 47.0.183.25447.0.183.2551,022
4747.0.184.0/2247.0.184.1 to 47.0.187.25447.0.187.2551,022
4847.0.188.0/2247.0.188.1 to 47.0.191.25447.0.191.2551,022
4947.0.192.0/2247.0.192.1 to 47.0.195.25447.0.195.2551,022
5047.0.196.0/2247.0.196.1 to 47.0.199.25447.0.199.2551,022
5147.0.200.0/2247.0.200.1 to 47.0.203.25447.0.203.2551,022
5247.0.204.0/2247.0.204.1 to 47.0.207.25447.0.207.2551,022
5347.0.208.0/2247.0.208.1 to 47.0.211.25447.0.211.2551,022
5447.0.212.0/2247.0.212.1 to 47.0.215.25447.0.215.2551,022
5547.0.216.0/2247.0.216.1 to 47.0.219.25447.0.219.2551,022
5647.0.220.0/2247.0.220.1 to 47.0.223.25447.0.223.2551,022
5747.0.224.0/2247.0.224.1 to 47.0.227.25447.0.227.2551,022
5847.0.228.0/2247.0.228.1 to 47.0.231.25447.0.231.2551,022
5947.0.232.0/2247.0.232.1 to 47.0.235.25447.0.235.2551,022
6047.0.236.0/2247.0.236.1 to 47.0.239.25447.0.239.2551,022
6147.0.240.0/2247.0.240.1 to 47.0.243.25447.0.243.2551,022
6247.0.244.0/2247.0.244.1 to 47.0.247.25447.0.247.2551,022
6347.0.248.0/2247.0.248.1 to 47.0.251.25447.0.251.2551,022
6447.0.252.0/2247.0.252.1 to 47.0.255.25447.0.255.2551,022
6547.1.0.0/2247.1.0.1 to 47.1.3.25447.1.3.2551,022
6647.1.4.0/2247.1.4.1 to 47.1.7.25447.1.7.2551,022
6747.1.8.0/2247.1.8.1 to 47.1.11.25447.1.11.2551,022
6847.1.12.0/2247.1.12.1 to 47.1.15.25447.1.15.2551,022
6947.1.16.0/2247.1.16.1 to 47.1.19.25447.1.19.2551,022
7047.1.20.0/2247.1.20.1 to 47.1.23.25447.1.23.2551,022
7147.1.24.0/2247.1.24.1 to 47.1.27.25447.1.27.2551,022
7247.1.28.0/2247.1.28.1 to 47.1.31.25447.1.31.2551,022
7347.1.32.0/2247.1.32.1 to 47.1.35.25447.1.35.2551,022
7447.1.36.0/2247.1.36.1 to 47.1.39.25447.1.39.2551,022
7547.1.40.0/2247.1.40.1 to 47.1.43.25447.1.43.2551,022
7647.1.44.0/2247.1.44.1 to 47.1.47.25447.1.47.2551,022
7747.1.48.0/2247.1.48.1 to 47.1.51.25447.1.51.2551,022
7847.1.52.0/2247.1.52.1 to 47.1.55.25447.1.55.2551,022
7947.1.56.0/2247.1.56.1 to 47.1.59.25447.1.59.2551,022
8047.1.60.0/2247.1.60.1 to 47.1.63.25447.1.63.2551,022
8147.1.64.0/2247.1.64.1 to 47.1.67.25447.1.67.2551,022
8247.1.68.0/2247.1.68.1 to 47.1.71.25447.1.71.2551,022
8347.1.72.0/2247.1.72.1 to 47.1.75.25447.1.75.2551,022
8447.1.76.0/2247.1.76.1 to 47.1.79.25447.1.79.2551,022
8547.1.80.0/2247.1.80.1 to 47.1.83.25447.1.83.2551,022
8647.1.84.0/2247.1.84.1 to 47.1.87.25447.1.87.2551,022
8747.1.88.0/2247.1.88.1 to 47.1.91.25447.1.91.2551,022
8847.1.92.0/2247.1.92.1 to 47.1.95.25447.1.95.2551,022
8947.1.96.0/2247.1.96.1 to 47.1.99.25447.1.99.2551,022
9047.1.100.0/2247.1.100.1 to 47.1.103.25447.1.103.2551,022
9147.1.104.0/2247.1.104.1 to 47.1.107.25447.1.107.2551,022
9247.1.108.0/2247.1.108.1 to 47.1.111.25447.1.111.2551,022
9347.1.112.0/2247.1.112.1 to 47.1.115.25447.1.115.2551,022
9447.1.116.0/2247.1.116.1 to 47.1.119.25447.1.119.2551,022
9547.1.120.0/2247.1.120.1 to 47.1.123.25447.1.123.2551,022
9647.1.124.0/2247.1.124.1 to 47.1.127.25447.1.127.2551,022
9747.1.128.0/2247.1.128.1 to 47.1.131.25447.1.131.2551,022
9847.1.132.0/2247.1.132.1 to 47.1.135.25447.1.135.2551,022
9947.1.136.0/2247.1.136.1 to 47.1.139.25447.1.139.2551,022
10047.1.140.0/2247.1.140.1 to 47.1.143.25447.1.143.2551,022
10147.1.144.0/2247.1.144.1 to 47.1.147.25447.1.147.2551,022
10247.1.148.0/2247.1.148.1 to 47.1.151.25447.1.151.2551,022
10347.1.152.0/2247.1.152.1 to 47.1.155.25447.1.155.2551,022
10447.1.156.0/2247.1.156.1 to 47.1.159.25447.1.159.2551,022
10547.1.160.0/2247.1.160.1 to 47.1.163.25447.1.163.2551,022
10647.1.164.0/2247.1.164.1 to 47.1.167.25447.1.167.2551,022
10747.1.168.0/2247.1.168.1 to 47.1.171.25447.1.171.2551,022
10847.1.172.0/2247.1.172.1 to 47.1.175.25447.1.175.2551,022
10947.1.176.0/2247.1.176.1 to 47.1.179.25447.1.179.2551,022
11047.1.180.0/2247.1.180.1 to 47.1.183.25447.1.183.2551,022
11147.1.184.0/2247.1.184.1 to 47.1.187.25447.1.187.2551,022
11247.1.188.0/2247.1.188.1 to 47.1.191.25447.1.191.2551,022
11347.1.192.0/2247.1.192.1 to 47.1.195.25447.1.195.2551,022
11447.1.196.0/2247.1.196.1 to 47.1.199.25447.1.199.2551,022
11547.1.200.0/2247.1.200.1 to 47.1.203.25447.1.203.2551,022
11647.1.204.0/2247.1.204.1 to 47.1.207.25447.1.207.2551,022
11747.1.208.0/2247.1.208.1 to 47.1.211.25447.1.211.2551,022
11847.1.212.0/2247.1.212.1 to 47.1.215.25447.1.215.2551,022
11947.1.216.0/2247.1.216.1 to 47.1.219.25447.1.219.2551,022
12047.1.220.0/2247.1.220.1 to 47.1.223.25447.1.223.2551,022
12147.1.224.0/2247.1.224.1 to 47.1.227.25447.1.227.2551,022
12247.1.228.0/2247.1.228.1 to 47.1.231.25447.1.231.2551,022
12347.1.232.0/2247.1.232.1 to 47.1.235.25447.1.235.2551,022
12447.1.236.0/2247.1.236.1 to 47.1.239.25447.1.239.2551,022
12547.1.240.0/2247.1.240.1 to 47.1.243.25447.1.243.2551,022
12647.1.244.0/2247.1.244.1 to 47.1.247.25447.1.247.2551,022
12747.1.248.0/2247.1.248.1 to 47.1.251.25447.1.251.2551,022
12847.1.252.0/2247.1.252.1 to 47.1.255.25447.1.255.2551,022
12947.2.0.0/2247.2.0.1 to 47.2.3.25447.2.3.2551,022
13047.2.4.0/2247.2.4.1 to 47.2.7.25447.2.7.2551,022
13147.2.8.0/2247.2.8.1 to 47.2.11.25447.2.11.2551,022
13247.2.12.0/2247.2.12.1 to 47.2.15.25447.2.15.2551,022
13347.2.16.0/2247.2.16.1 to 47.2.19.25447.2.19.2551,022
13447.2.20.0/2247.2.20.1 to 47.2.23.25447.2.23.2551,022
13547.2.24.0/2247.2.24.1 to 47.2.27.25447.2.27.2551,022
13647.2.28.0/2247.2.28.1 to 47.2.31.25447.2.31.2551,022
13747.2.32.0/2247.2.32.1 to 47.2.35.25447.2.35.2551,022
13847.2.36.0/2247.2.36.1 to 47.2.39.25447.2.39.2551,022
13947.2.40.0/2247.2.40.1 to 47.2.43.25447.2.43.2551,022
14047.2.44.0/2247.2.44.1 to 47.2.47.25447.2.47.2551,022
14147.2.48.0/2247.2.48.1 to 47.2.51.25447.2.51.2551,022
14247.2.52.0/2247.2.52.1 to 47.2.55.25447.2.55.2551,022
14347.2.56.0/2247.2.56.1 to 47.2.59.25447.2.59.2551,022
14447.2.60.0/2247.2.60.1 to 47.2.63.25447.2.63.2551,022
14547.2.64.0/2247.2.64.1 to 47.2.67.25447.2.67.2551,022
14647.2.68.0/2247.2.68.1 to 47.2.71.25447.2.71.2551,022
14747.2.72.0/2247.2.72.1 to 47.2.75.25447.2.75.2551,022
14847.2.76.0/2247.2.76.1 to 47.2.79.25447.2.79.2551,022
14947.2.80.0/2247.2.80.1 to 47.2.83.25447.2.83.2551,022
15047.2.84.0/2247.2.84.1 to 47.2.87.25447.2.87.2551,022
15147.2.88.0/2247.2.88.1 to 47.2.91.25447.2.91.2551,022
15247.2.92.0/2247.2.92.1 to 47.2.95.25447.2.95.2551,022
15347.2.96.0/2247.2.96.1 to 47.2.99.25447.2.99.2551,022
15447.2.100.0/2247.2.100.1 to 47.2.103.25447.2.103.2551,022
15547.2.104.0/2247.2.104.1 to 47.2.107.25447.2.107.2551,022
15647.2.108.0/2247.2.108.1 to 47.2.111.25447.2.111.2551,022
15747.2.112.0/2247.2.112.1 to 47.2.115.25447.2.115.2551,022
15847.2.116.0/2247.2.116.1 to 47.2.119.25447.2.119.2551,022
15947.2.120.0/2247.2.120.1 to 47.2.123.25447.2.123.2551,022
16047.2.124.0/2247.2.124.1 to 47.2.127.25447.2.127.2551,022
16147.2.128.0/2247.2.128.1 to 47.2.131.25447.2.131.2551,022
16247.2.132.0/2247.2.132.1 to 47.2.135.25447.2.135.2551,022
16347.2.136.0/2247.2.136.1 to 47.2.139.25447.2.139.2551,022
16447.2.140.0/2247.2.140.1 to 47.2.143.25447.2.143.2551,022
16547.2.144.0/2247.2.144.1 to 47.2.147.25447.2.147.2551,022
16647.2.148.0/2247.2.148.1 to 47.2.151.25447.2.151.2551,022
16747.2.152.0/2247.2.152.1 to 47.2.155.25447.2.155.2551,022
16847.2.156.0/2247.2.156.1 to 47.2.159.25447.2.159.2551,022
16947.2.160.0/2247.2.160.1 to 47.2.163.25447.2.163.2551,022
17047.2.164.0/2247.2.164.1 to 47.2.167.25447.2.167.2551,022
17147.2.168.0/2247.2.168.1 to 47.2.171.25447.2.171.2551,022
17247.2.172.0/2247.2.172.1 to 47.2.175.25447.2.175.2551,022
17347.2.176.0/2247.2.176.1 to 47.2.179.25447.2.179.2551,022
17447.2.180.0/2247.2.180.1 to 47.2.183.25447.2.183.2551,022
17547.2.184.0/2247.2.184.1 to 47.2.187.25447.2.187.2551,022
17647.2.188.0/2247.2.188.1 to 47.2.191.25447.2.191.2551,022
17747.2.192.0/2247.2.192.1 to 47.2.195.25447.2.195.2551,022
17847.2.196.0/2247.2.196.1 to 47.2.199.25447.2.199.2551,022
17947.2.200.0/2247.2.200.1 to 47.2.203.25447.2.203.2551,022
18047.2.204.0/2247.2.204.1 to 47.2.207.25447.2.207.2551,022
18147.2.208.0/2247.2.208.1 to 47.2.211.25447.2.211.2551,022
18247.2.212.0/2247.2.212.1 to 47.2.215.25447.2.215.2551,022
18347.2.216.0/2247.2.216.1 to 47.2.219.25447.2.219.2551,022
18447.2.220.0/2247.2.220.1 to 47.2.223.25447.2.223.2551,022
18547.2.224.0/2247.2.224.1 to 47.2.227.25447.2.227.2551,022
18647.2.228.0/2247.2.228.1 to 47.2.231.25447.2.231.2551,022
18747.2.232.0/2247.2.232.1 to 47.2.235.25447.2.235.2551,022
18847.2.236.0/2247.2.236.1 to 47.2.239.25447.2.239.2551,022
18947.2.240.0/2247.2.240.1 to 47.2.243.25447.2.243.2551,022
19047.2.244.0/2247.2.244.1 to 47.2.247.25447.2.247.2551,022
19147.2.248.0/2247.2.248.1 to 47.2.251.25447.2.251.2551,022
19247.2.252.0/2247.2.252.1 to 47.2.255.25447.2.255.2551,022
19347.3.0.0/2247.3.0.1 to 47.3.3.25447.3.3.2551,022
19447.3.4.0/2247.3.4.1 to 47.3.7.25447.3.7.2551,022
19547.3.8.0/2247.3.8.1 to 47.3.11.25447.3.11.2551,022
19647.3.12.0/2247.3.12.1 to 47.3.15.25447.3.15.2551,022
19747.3.16.0/2247.3.16.1 to 47.3.19.25447.3.19.2551,022
19847.3.20.0/2247.3.20.1 to 47.3.23.25447.3.23.2551,022
19947.3.24.0/2247.3.24.1 to 47.3.27.25447.3.27.2551,022
20047.3.28.0/2247.3.28.1 to 47.3.31.25447.3.31.2551,022
20147.3.32.0/2247.3.32.1 to 47.3.35.25447.3.35.2551,022
20247.3.36.0/2247.3.36.1 to 47.3.39.25447.3.39.2551,022
20347.3.40.0/2247.3.40.1 to 47.3.43.25447.3.43.2551,022
20447.3.44.0/2247.3.44.1 to 47.3.47.25447.3.47.2551,022
20547.3.48.0/2247.3.48.1 to 47.3.51.25447.3.51.2551,022
20647.3.52.0/2247.3.52.1 to 47.3.55.25447.3.55.2551,022
20747.3.56.0/2247.3.56.1 to 47.3.59.25447.3.59.2551,022
20847.3.60.0/2247.3.60.1 to 47.3.63.25447.3.63.2551,022
20947.3.64.0/2247.3.64.1 to 47.3.67.25447.3.67.2551,022
21047.3.68.0/2247.3.68.1 to 47.3.71.25447.3.71.2551,022
21147.3.72.0/2247.3.72.1 to 47.3.75.25447.3.75.2551,022
21247.3.76.0/2247.3.76.1 to 47.3.79.25447.3.79.2551,022
21347.3.80.0/2247.3.80.1 to 47.3.83.25447.3.83.2551,022
21447.3.84.0/2247.3.84.1 to 47.3.87.25447.3.87.2551,022
21547.3.88.0/2247.3.88.1 to 47.3.91.25447.3.91.2551,022
21647.3.92.0/2247.3.92.1 to 47.3.95.25447.3.95.2551,022
21747.3.96.0/2247.3.96.1 to 47.3.99.25447.3.99.2551,022
21847.3.100.0/2247.3.100.1 to 47.3.103.25447.3.103.2551,022
21947.3.104.0/2247.3.104.1 to 47.3.107.25447.3.107.2551,022
22047.3.108.0/2247.3.108.1 to 47.3.111.25447.3.111.2551,022
22147.3.112.0/2247.3.112.1 to 47.3.115.25447.3.115.2551,022
22247.3.116.0/2247.3.116.1 to 47.3.119.25447.3.119.2551,022
22347.3.120.0/2247.3.120.1 to 47.3.123.25447.3.123.2551,022
22447.3.124.0/2247.3.124.1 to 47.3.127.25447.3.127.2551,022
22547.3.128.0/2247.3.128.1 to 47.3.131.25447.3.131.2551,022
22647.3.132.0/2247.3.132.1 to 47.3.135.25447.3.135.2551,022
22747.3.136.0/2247.3.136.1 to 47.3.139.25447.3.139.2551,022
22847.3.140.0/2247.3.140.1 to 47.3.143.25447.3.143.2551,022
22947.3.144.0/2247.3.144.1 to 47.3.147.25447.3.147.2551,022
23047.3.148.0/2247.3.148.1 to 47.3.151.25447.3.151.2551,022
23147.3.152.0/2247.3.152.1 to 47.3.155.25447.3.155.2551,022
23247.3.156.0/2247.3.156.1 to 47.3.159.25447.3.159.2551,022
23347.3.160.0/2247.3.160.1 to 47.3.163.25447.3.163.2551,022
23447.3.164.0/2247.3.164.1 to 47.3.167.25447.3.167.2551,022
23547.3.168.0/2247.3.168.1 to 47.3.171.25447.3.171.2551,022
23647.3.172.0/2247.3.172.1 to 47.3.175.25447.3.175.2551,022
23747.3.176.0/2247.3.176.1 to 47.3.179.25447.3.179.2551,022
23847.3.180.0/2247.3.180.1 to 47.3.183.25447.3.183.2551,022
23947.3.184.0/2247.3.184.1 to 47.3.187.25447.3.187.2551,022
24047.3.188.0/2247.3.188.1 to 47.3.191.25447.3.191.2551,022
24147.3.192.0/2247.3.192.1 to 47.3.195.25447.3.195.2551,022
24247.3.196.0/2247.3.196.1 to 47.3.199.25447.3.199.2551,022
24347.3.200.0/2247.3.200.1 to 47.3.203.25447.3.203.2551,022
24447.3.204.0/2247.3.204.1 to 47.3.207.25447.3.207.2551,022
24547.3.208.0/2247.3.208.1 to 47.3.211.25447.3.211.2551,022
24647.3.212.0/2247.3.212.1 to 47.3.215.25447.3.215.2551,022
24747.3.216.0/2247.3.216.1 to 47.3.219.25447.3.219.2551,022
24847.3.220.0/2247.3.220.1 to 47.3.223.25447.3.223.2551,022
24947.3.224.0/2247.3.224.1 to 47.3.227.25447.3.227.2551,022
25047.3.228.0/2247.3.228.1 to 47.3.231.25447.3.231.2551,022
25147.3.232.0/2247.3.232.1 to 47.3.235.25447.3.235.2551,022
25247.3.236.0/2247.3.236.1 to 47.3.239.25447.3.239.2551,022
25347.3.240.0/2247.3.240.1 to 47.3.243.25447.3.243.2551,022
25447.3.244.0/2247.3.244.1 to 47.3.247.25447.3.247.2551,022
25547.3.248.0/2247.3.248.1 to 47.3.251.25447.3.251.2551,022
25647.3.252.0/2247.3.252.1 to 47.3.255.25447.3.255.2551,022

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.