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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/20
/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 1,024 subnets of /20; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
147.0.0.0/2047.0.0.1 to 47.0.15.25447.0.15.2554,094
247.0.16.0/2047.0.16.1 to 47.0.31.25447.0.31.2554,094
347.0.32.0/2047.0.32.1 to 47.0.47.25447.0.47.2554,094
447.0.48.0/2047.0.48.1 to 47.0.63.25447.0.63.2554,094
547.0.64.0/2047.0.64.1 to 47.0.79.25447.0.79.2554,094
647.0.80.0/2047.0.80.1 to 47.0.95.25447.0.95.2554,094
747.0.96.0/2047.0.96.1 to 47.0.111.25447.0.111.2554,094
847.0.112.0/2047.0.112.1 to 47.0.127.25447.0.127.2554,094
947.0.128.0/2047.0.128.1 to 47.0.143.25447.0.143.2554,094
1047.0.144.0/2047.0.144.1 to 47.0.159.25447.0.159.2554,094
1147.0.160.0/2047.0.160.1 to 47.0.175.25447.0.175.2554,094
1247.0.176.0/2047.0.176.1 to 47.0.191.25447.0.191.2554,094
1347.0.192.0/2047.0.192.1 to 47.0.207.25447.0.207.2554,094
1447.0.208.0/2047.0.208.1 to 47.0.223.25447.0.223.2554,094
1547.0.224.0/2047.0.224.1 to 47.0.239.25447.0.239.2554,094
1647.0.240.0/2047.0.240.1 to 47.0.255.25447.0.255.2554,094
1747.1.0.0/2047.1.0.1 to 47.1.15.25447.1.15.2554,094
1847.1.16.0/2047.1.16.1 to 47.1.31.25447.1.31.2554,094
1947.1.32.0/2047.1.32.1 to 47.1.47.25447.1.47.2554,094
2047.1.48.0/2047.1.48.1 to 47.1.63.25447.1.63.2554,094
2147.1.64.0/2047.1.64.1 to 47.1.79.25447.1.79.2554,094
2247.1.80.0/2047.1.80.1 to 47.1.95.25447.1.95.2554,094
2347.1.96.0/2047.1.96.1 to 47.1.111.25447.1.111.2554,094
2447.1.112.0/2047.1.112.1 to 47.1.127.25447.1.127.2554,094
2547.1.128.0/2047.1.128.1 to 47.1.143.25447.1.143.2554,094
2647.1.144.0/2047.1.144.1 to 47.1.159.25447.1.159.2554,094
2747.1.160.0/2047.1.160.1 to 47.1.175.25447.1.175.2554,094
2847.1.176.0/2047.1.176.1 to 47.1.191.25447.1.191.2554,094
2947.1.192.0/2047.1.192.1 to 47.1.207.25447.1.207.2554,094
3047.1.208.0/2047.1.208.1 to 47.1.223.25447.1.223.2554,094
3147.1.224.0/2047.1.224.1 to 47.1.239.25447.1.239.2554,094
3247.1.240.0/2047.1.240.1 to 47.1.255.25447.1.255.2554,094
3347.2.0.0/2047.2.0.1 to 47.2.15.25447.2.15.2554,094
3447.2.16.0/2047.2.16.1 to 47.2.31.25447.2.31.2554,094
3547.2.32.0/2047.2.32.1 to 47.2.47.25447.2.47.2554,094
3647.2.48.0/2047.2.48.1 to 47.2.63.25447.2.63.2554,094
3747.2.64.0/2047.2.64.1 to 47.2.79.25447.2.79.2554,094
3847.2.80.0/2047.2.80.1 to 47.2.95.25447.2.95.2554,094
3947.2.96.0/2047.2.96.1 to 47.2.111.25447.2.111.2554,094
4047.2.112.0/2047.2.112.1 to 47.2.127.25447.2.127.2554,094
4147.2.128.0/2047.2.128.1 to 47.2.143.25447.2.143.2554,094
4247.2.144.0/2047.2.144.1 to 47.2.159.25447.2.159.2554,094
4347.2.160.0/2047.2.160.1 to 47.2.175.25447.2.175.2554,094
4447.2.176.0/2047.2.176.1 to 47.2.191.25447.2.191.2554,094
4547.2.192.0/2047.2.192.1 to 47.2.207.25447.2.207.2554,094
4647.2.208.0/2047.2.208.1 to 47.2.223.25447.2.223.2554,094
4747.2.224.0/2047.2.224.1 to 47.2.239.25447.2.239.2554,094
4847.2.240.0/2047.2.240.1 to 47.2.255.25447.2.255.2554,094
4947.3.0.0/2047.3.0.1 to 47.3.15.25447.3.15.2554,094
5047.3.16.0/2047.3.16.1 to 47.3.31.25447.3.31.2554,094
5147.3.32.0/2047.3.32.1 to 47.3.47.25447.3.47.2554,094
5247.3.48.0/2047.3.48.1 to 47.3.63.25447.3.63.2554,094
5347.3.64.0/2047.3.64.1 to 47.3.79.25447.3.79.2554,094
5447.3.80.0/2047.3.80.1 to 47.3.95.25447.3.95.2554,094
5547.3.96.0/2047.3.96.1 to 47.3.111.25447.3.111.2554,094
5647.3.112.0/2047.3.112.1 to 47.3.127.25447.3.127.2554,094
5747.3.128.0/2047.3.128.1 to 47.3.143.25447.3.143.2554,094
5847.3.144.0/2047.3.144.1 to 47.3.159.25447.3.159.2554,094
5947.3.160.0/2047.3.160.1 to 47.3.175.25447.3.175.2554,094
6047.3.176.0/2047.3.176.1 to 47.3.191.25447.3.191.2554,094
6147.3.192.0/2047.3.192.1 to 47.3.207.25447.3.207.2554,094
6247.3.208.0/2047.3.208.1 to 47.3.223.25447.3.223.2554,094
6347.3.224.0/2047.3.224.1 to 47.3.239.25447.3.239.2554,094
6447.3.240.0/2047.3.240.1 to 47.3.255.25447.3.255.2554,094
6547.4.0.0/2047.4.0.1 to 47.4.15.25447.4.15.2554,094
6647.4.16.0/2047.4.16.1 to 47.4.31.25447.4.31.2554,094
6747.4.32.0/2047.4.32.1 to 47.4.47.25447.4.47.2554,094
6847.4.48.0/2047.4.48.1 to 47.4.63.25447.4.63.2554,094
6947.4.64.0/2047.4.64.1 to 47.4.79.25447.4.79.2554,094
7047.4.80.0/2047.4.80.1 to 47.4.95.25447.4.95.2554,094
7147.4.96.0/2047.4.96.1 to 47.4.111.25447.4.111.2554,094
7247.4.112.0/2047.4.112.1 to 47.4.127.25447.4.127.2554,094
7347.4.128.0/2047.4.128.1 to 47.4.143.25447.4.143.2554,094
7447.4.144.0/2047.4.144.1 to 47.4.159.25447.4.159.2554,094
7547.4.160.0/2047.4.160.1 to 47.4.175.25447.4.175.2554,094
7647.4.176.0/2047.4.176.1 to 47.4.191.25447.4.191.2554,094
7747.4.192.0/2047.4.192.1 to 47.4.207.25447.4.207.2554,094
7847.4.208.0/2047.4.208.1 to 47.4.223.25447.4.223.2554,094
7947.4.224.0/2047.4.224.1 to 47.4.239.25447.4.239.2554,094
8047.4.240.0/2047.4.240.1 to 47.4.255.25447.4.255.2554,094
8147.5.0.0/2047.5.0.1 to 47.5.15.25447.5.15.2554,094
8247.5.16.0/2047.5.16.1 to 47.5.31.25447.5.31.2554,094
8347.5.32.0/2047.5.32.1 to 47.5.47.25447.5.47.2554,094
8447.5.48.0/2047.5.48.1 to 47.5.63.25447.5.63.2554,094
8547.5.64.0/2047.5.64.1 to 47.5.79.25447.5.79.2554,094
8647.5.80.0/2047.5.80.1 to 47.5.95.25447.5.95.2554,094
8747.5.96.0/2047.5.96.1 to 47.5.111.25447.5.111.2554,094
8847.5.112.0/2047.5.112.1 to 47.5.127.25447.5.127.2554,094
8947.5.128.0/2047.5.128.1 to 47.5.143.25447.5.143.2554,094
9047.5.144.0/2047.5.144.1 to 47.5.159.25447.5.159.2554,094
9147.5.160.0/2047.5.160.1 to 47.5.175.25447.5.175.2554,094
9247.5.176.0/2047.5.176.1 to 47.5.191.25447.5.191.2554,094
9347.5.192.0/2047.5.192.1 to 47.5.207.25447.5.207.2554,094
9447.5.208.0/2047.5.208.1 to 47.5.223.25447.5.223.2554,094
9547.5.224.0/2047.5.224.1 to 47.5.239.25447.5.239.2554,094
9647.5.240.0/2047.5.240.1 to 47.5.255.25447.5.255.2554,094
9747.6.0.0/2047.6.0.1 to 47.6.15.25447.6.15.2554,094
9847.6.16.0/2047.6.16.1 to 47.6.31.25447.6.31.2554,094
9947.6.32.0/2047.6.32.1 to 47.6.47.25447.6.47.2554,094
10047.6.48.0/2047.6.48.1 to 47.6.63.25447.6.63.2554,094
10147.6.64.0/2047.6.64.1 to 47.6.79.25447.6.79.2554,094
10247.6.80.0/2047.6.80.1 to 47.6.95.25447.6.95.2554,094
10347.6.96.0/2047.6.96.1 to 47.6.111.25447.6.111.2554,094
10447.6.112.0/2047.6.112.1 to 47.6.127.25447.6.127.2554,094
10547.6.128.0/2047.6.128.1 to 47.6.143.25447.6.143.2554,094
10647.6.144.0/2047.6.144.1 to 47.6.159.25447.6.159.2554,094
10747.6.160.0/2047.6.160.1 to 47.6.175.25447.6.175.2554,094
10847.6.176.0/2047.6.176.1 to 47.6.191.25447.6.191.2554,094
10947.6.192.0/2047.6.192.1 to 47.6.207.25447.6.207.2554,094
11047.6.208.0/2047.6.208.1 to 47.6.223.25447.6.223.2554,094
11147.6.224.0/2047.6.224.1 to 47.6.239.25447.6.239.2554,094
11247.6.240.0/2047.6.240.1 to 47.6.255.25447.6.255.2554,094
11347.7.0.0/2047.7.0.1 to 47.7.15.25447.7.15.2554,094
11447.7.16.0/2047.7.16.1 to 47.7.31.25447.7.31.2554,094
11547.7.32.0/2047.7.32.1 to 47.7.47.25447.7.47.2554,094
11647.7.48.0/2047.7.48.1 to 47.7.63.25447.7.63.2554,094
11747.7.64.0/2047.7.64.1 to 47.7.79.25447.7.79.2554,094
11847.7.80.0/2047.7.80.1 to 47.7.95.25447.7.95.2554,094
11947.7.96.0/2047.7.96.1 to 47.7.111.25447.7.111.2554,094
12047.7.112.0/2047.7.112.1 to 47.7.127.25447.7.127.2554,094
12147.7.128.0/2047.7.128.1 to 47.7.143.25447.7.143.2554,094
12247.7.144.0/2047.7.144.1 to 47.7.159.25447.7.159.2554,094
12347.7.160.0/2047.7.160.1 to 47.7.175.25447.7.175.2554,094
12447.7.176.0/2047.7.176.1 to 47.7.191.25447.7.191.2554,094
12547.7.192.0/2047.7.192.1 to 47.7.207.25447.7.207.2554,094
12647.7.208.0/2047.7.208.1 to 47.7.223.25447.7.223.2554,094
12747.7.224.0/2047.7.224.1 to 47.7.239.25447.7.239.2554,094
12847.7.240.0/2047.7.240.1 to 47.7.255.25447.7.255.2554,094
12947.8.0.0/2047.8.0.1 to 47.8.15.25447.8.15.2554,094
13047.8.16.0/2047.8.16.1 to 47.8.31.25447.8.31.2554,094
13147.8.32.0/2047.8.32.1 to 47.8.47.25447.8.47.2554,094
13247.8.48.0/2047.8.48.1 to 47.8.63.25447.8.63.2554,094
13347.8.64.0/2047.8.64.1 to 47.8.79.25447.8.79.2554,094
13447.8.80.0/2047.8.80.1 to 47.8.95.25447.8.95.2554,094
13547.8.96.0/2047.8.96.1 to 47.8.111.25447.8.111.2554,094
13647.8.112.0/2047.8.112.1 to 47.8.127.25447.8.127.2554,094
13747.8.128.0/2047.8.128.1 to 47.8.143.25447.8.143.2554,094
13847.8.144.0/2047.8.144.1 to 47.8.159.25447.8.159.2554,094
13947.8.160.0/2047.8.160.1 to 47.8.175.25447.8.175.2554,094
14047.8.176.0/2047.8.176.1 to 47.8.191.25447.8.191.2554,094
14147.8.192.0/2047.8.192.1 to 47.8.207.25447.8.207.2554,094
14247.8.208.0/2047.8.208.1 to 47.8.223.25447.8.223.2554,094
14347.8.224.0/2047.8.224.1 to 47.8.239.25447.8.239.2554,094
14447.8.240.0/2047.8.240.1 to 47.8.255.25447.8.255.2554,094
14547.9.0.0/2047.9.0.1 to 47.9.15.25447.9.15.2554,094
14647.9.16.0/2047.9.16.1 to 47.9.31.25447.9.31.2554,094
14747.9.32.0/2047.9.32.1 to 47.9.47.25447.9.47.2554,094
14847.9.48.0/2047.9.48.1 to 47.9.63.25447.9.63.2554,094
14947.9.64.0/2047.9.64.1 to 47.9.79.25447.9.79.2554,094
15047.9.80.0/2047.9.80.1 to 47.9.95.25447.9.95.2554,094
15147.9.96.0/2047.9.96.1 to 47.9.111.25447.9.111.2554,094
15247.9.112.0/2047.9.112.1 to 47.9.127.25447.9.127.2554,094
15347.9.128.0/2047.9.128.1 to 47.9.143.25447.9.143.2554,094
15447.9.144.0/2047.9.144.1 to 47.9.159.25447.9.159.2554,094
15547.9.160.0/2047.9.160.1 to 47.9.175.25447.9.175.2554,094
15647.9.176.0/2047.9.176.1 to 47.9.191.25447.9.191.2554,094
15747.9.192.0/2047.9.192.1 to 47.9.207.25447.9.207.2554,094
15847.9.208.0/2047.9.208.1 to 47.9.223.25447.9.223.2554,094
15947.9.224.0/2047.9.224.1 to 47.9.239.25447.9.239.2554,094
16047.9.240.0/2047.9.240.1 to 47.9.255.25447.9.255.2554,094
16147.10.0.0/2047.10.0.1 to 47.10.15.25447.10.15.2554,094
16247.10.16.0/2047.10.16.1 to 47.10.31.25447.10.31.2554,094
16347.10.32.0/2047.10.32.1 to 47.10.47.25447.10.47.2554,094
16447.10.48.0/2047.10.48.1 to 47.10.63.25447.10.63.2554,094
16547.10.64.0/2047.10.64.1 to 47.10.79.25447.10.79.2554,094
16647.10.80.0/2047.10.80.1 to 47.10.95.25447.10.95.2554,094
16747.10.96.0/2047.10.96.1 to 47.10.111.25447.10.111.2554,094
16847.10.112.0/2047.10.112.1 to 47.10.127.25447.10.127.2554,094
16947.10.128.0/2047.10.128.1 to 47.10.143.25447.10.143.2554,094
17047.10.144.0/2047.10.144.1 to 47.10.159.25447.10.159.2554,094
17147.10.160.0/2047.10.160.1 to 47.10.175.25447.10.175.2554,094
17247.10.176.0/2047.10.176.1 to 47.10.191.25447.10.191.2554,094
17347.10.192.0/2047.10.192.1 to 47.10.207.25447.10.207.2554,094
17447.10.208.0/2047.10.208.1 to 47.10.223.25447.10.223.2554,094
17547.10.224.0/2047.10.224.1 to 47.10.239.25447.10.239.2554,094
17647.10.240.0/2047.10.240.1 to 47.10.255.25447.10.255.2554,094
17747.11.0.0/2047.11.0.1 to 47.11.15.25447.11.15.2554,094
17847.11.16.0/2047.11.16.1 to 47.11.31.25447.11.31.2554,094
17947.11.32.0/2047.11.32.1 to 47.11.47.25447.11.47.2554,094
18047.11.48.0/2047.11.48.1 to 47.11.63.25447.11.63.2554,094
18147.11.64.0/2047.11.64.1 to 47.11.79.25447.11.79.2554,094
18247.11.80.0/2047.11.80.1 to 47.11.95.25447.11.95.2554,094
18347.11.96.0/2047.11.96.1 to 47.11.111.25447.11.111.2554,094
18447.11.112.0/2047.11.112.1 to 47.11.127.25447.11.127.2554,094
18547.11.128.0/2047.11.128.1 to 47.11.143.25447.11.143.2554,094
18647.11.144.0/2047.11.144.1 to 47.11.159.25447.11.159.2554,094
18747.11.160.0/2047.11.160.1 to 47.11.175.25447.11.175.2554,094
18847.11.176.0/2047.11.176.1 to 47.11.191.25447.11.191.2554,094
18947.11.192.0/2047.11.192.1 to 47.11.207.25447.11.207.2554,094
19047.11.208.0/2047.11.208.1 to 47.11.223.25447.11.223.2554,094
19147.11.224.0/2047.11.224.1 to 47.11.239.25447.11.239.2554,094
19247.11.240.0/2047.11.240.1 to 47.11.255.25447.11.255.2554,094
19347.12.0.0/2047.12.0.1 to 47.12.15.25447.12.15.2554,094
19447.12.16.0/2047.12.16.1 to 47.12.31.25447.12.31.2554,094
19547.12.32.0/2047.12.32.1 to 47.12.47.25447.12.47.2554,094
19647.12.48.0/2047.12.48.1 to 47.12.63.25447.12.63.2554,094
19747.12.64.0/2047.12.64.1 to 47.12.79.25447.12.79.2554,094
19847.12.80.0/2047.12.80.1 to 47.12.95.25447.12.95.2554,094
19947.12.96.0/2047.12.96.1 to 47.12.111.25447.12.111.2554,094
20047.12.112.0/2047.12.112.1 to 47.12.127.25447.12.127.2554,094
20147.12.128.0/2047.12.128.1 to 47.12.143.25447.12.143.2554,094
20247.12.144.0/2047.12.144.1 to 47.12.159.25447.12.159.2554,094
20347.12.160.0/2047.12.160.1 to 47.12.175.25447.12.175.2554,094
20447.12.176.0/2047.12.176.1 to 47.12.191.25447.12.191.2554,094
20547.12.192.0/2047.12.192.1 to 47.12.207.25447.12.207.2554,094
20647.12.208.0/2047.12.208.1 to 47.12.223.25447.12.223.2554,094
20747.12.224.0/2047.12.224.1 to 47.12.239.25447.12.239.2554,094
20847.12.240.0/2047.12.240.1 to 47.12.255.25447.12.255.2554,094
20947.13.0.0/2047.13.0.1 to 47.13.15.25447.13.15.2554,094
21047.13.16.0/2047.13.16.1 to 47.13.31.25447.13.31.2554,094
21147.13.32.0/2047.13.32.1 to 47.13.47.25447.13.47.2554,094
21247.13.48.0/2047.13.48.1 to 47.13.63.25447.13.63.2554,094
21347.13.64.0/2047.13.64.1 to 47.13.79.25447.13.79.2554,094
21447.13.80.0/2047.13.80.1 to 47.13.95.25447.13.95.2554,094
21547.13.96.0/2047.13.96.1 to 47.13.111.25447.13.111.2554,094
21647.13.112.0/2047.13.112.1 to 47.13.127.25447.13.127.2554,094
21747.13.128.0/2047.13.128.1 to 47.13.143.25447.13.143.2554,094
21847.13.144.0/2047.13.144.1 to 47.13.159.25447.13.159.2554,094
21947.13.160.0/2047.13.160.1 to 47.13.175.25447.13.175.2554,094
22047.13.176.0/2047.13.176.1 to 47.13.191.25447.13.191.2554,094
22147.13.192.0/2047.13.192.1 to 47.13.207.25447.13.207.2554,094
22247.13.208.0/2047.13.208.1 to 47.13.223.25447.13.223.2554,094
22347.13.224.0/2047.13.224.1 to 47.13.239.25447.13.239.2554,094
22447.13.240.0/2047.13.240.1 to 47.13.255.25447.13.255.2554,094
22547.14.0.0/2047.14.0.1 to 47.14.15.25447.14.15.2554,094
22647.14.16.0/2047.14.16.1 to 47.14.31.25447.14.31.2554,094
22747.14.32.0/2047.14.32.1 to 47.14.47.25447.14.47.2554,094
22847.14.48.0/2047.14.48.1 to 47.14.63.25447.14.63.2554,094
22947.14.64.0/2047.14.64.1 to 47.14.79.25447.14.79.2554,094
23047.14.80.0/2047.14.80.1 to 47.14.95.25447.14.95.2554,094
23147.14.96.0/2047.14.96.1 to 47.14.111.25447.14.111.2554,094
23247.14.112.0/2047.14.112.1 to 47.14.127.25447.14.127.2554,094
23347.14.128.0/2047.14.128.1 to 47.14.143.25447.14.143.2554,094
23447.14.144.0/2047.14.144.1 to 47.14.159.25447.14.159.2554,094
23547.14.160.0/2047.14.160.1 to 47.14.175.25447.14.175.2554,094
23647.14.176.0/2047.14.176.1 to 47.14.191.25447.14.191.2554,094
23747.14.192.0/2047.14.192.1 to 47.14.207.25447.14.207.2554,094
23847.14.208.0/2047.14.208.1 to 47.14.223.25447.14.223.2554,094
23947.14.224.0/2047.14.224.1 to 47.14.239.25447.14.239.2554,094
24047.14.240.0/2047.14.240.1 to 47.14.255.25447.14.255.2554,094
24147.15.0.0/2047.15.0.1 to 47.15.15.25447.15.15.2554,094
24247.15.16.0/2047.15.16.1 to 47.15.31.25447.15.31.2554,094
24347.15.32.0/2047.15.32.1 to 47.15.47.25447.15.47.2554,094
24447.15.48.0/2047.15.48.1 to 47.15.63.25447.15.63.2554,094
24547.15.64.0/2047.15.64.1 to 47.15.79.25447.15.79.2554,094
24647.15.80.0/2047.15.80.1 to 47.15.95.25447.15.95.2554,094
24747.15.96.0/2047.15.96.1 to 47.15.111.25447.15.111.2554,094
24847.15.112.0/2047.15.112.1 to 47.15.127.25447.15.127.2554,094
24947.15.128.0/2047.15.128.1 to 47.15.143.25447.15.143.2554,094
25047.15.144.0/2047.15.144.1 to 47.15.159.25447.15.159.2554,094
25147.15.160.0/2047.15.160.1 to 47.15.175.25447.15.175.2554,094
25247.15.176.0/2047.15.176.1 to 47.15.191.25447.15.191.2554,094
25347.15.192.0/2047.15.192.1 to 47.15.207.25447.15.207.2554,094
25447.15.208.0/2047.15.208.1 to 47.15.223.25447.15.223.2554,094
25547.15.224.0/2047.15.224.1 to 47.15.239.25447.15.239.2554,094
25647.15.240.0/2047.15.240.1 to 47.15.255.25447.15.255.2554,094

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.