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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.

Network61.0.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
61.0.0.0
Broadcast address
61.63.255.255
First usable
61.0.0.1
Last usable
61.63.255.254
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 3D000000 · Integer 1023410176 to 1027604479
Reverse DNS zones
0.61.in-addr.arpa
1.61.in-addr.arpa
2.61.in-addr.arpa
3.61.in-addr.arpa
4.61.in-addr.arpa
5.61.in-addr.arpa
6.61.in-addr.arpa
7.61.in-addr.arpa
8.61.in-addr.arpa
9.61.in-addr.arpa
10.61.in-addr.arpa
11.61.in-addr.arpa
12.61.in-addr.arpa
13.61.in-addr.arpa
14.61.in-addr.arpa
15.61.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
Address00111101.00000000.00000000.0000000061.0.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network00111101.00000000.00000000.0000000061.0.0.0
Broadcast00111101.00111111.11111111.1111111161.63.255.255
Split into smaller subnets/19
/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)

61.0.0.0/10 makes 512 subnets of /19; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
161.0.0.0/1961.0.0.1 to 61.0.31.25461.0.31.2558,190
261.0.32.0/1961.0.32.1 to 61.0.63.25461.0.63.2558,190
361.0.64.0/1961.0.64.1 to 61.0.95.25461.0.95.2558,190
461.0.96.0/1961.0.96.1 to 61.0.127.25461.0.127.2558,190
561.0.128.0/1961.0.128.1 to 61.0.159.25461.0.159.2558,190
661.0.160.0/1961.0.160.1 to 61.0.191.25461.0.191.2558,190
761.0.192.0/1961.0.192.1 to 61.0.223.25461.0.223.2558,190
861.0.224.0/1961.0.224.1 to 61.0.255.25461.0.255.2558,190
961.1.0.0/1961.1.0.1 to 61.1.31.25461.1.31.2558,190
1061.1.32.0/1961.1.32.1 to 61.1.63.25461.1.63.2558,190
1161.1.64.0/1961.1.64.1 to 61.1.95.25461.1.95.2558,190
1261.1.96.0/1961.1.96.1 to 61.1.127.25461.1.127.2558,190
1361.1.128.0/1961.1.128.1 to 61.1.159.25461.1.159.2558,190
1461.1.160.0/1961.1.160.1 to 61.1.191.25461.1.191.2558,190
1561.1.192.0/1961.1.192.1 to 61.1.223.25461.1.223.2558,190
1661.1.224.0/1961.1.224.1 to 61.1.255.25461.1.255.2558,190
1761.2.0.0/1961.2.0.1 to 61.2.31.25461.2.31.2558,190
1861.2.32.0/1961.2.32.1 to 61.2.63.25461.2.63.2558,190
1961.2.64.0/1961.2.64.1 to 61.2.95.25461.2.95.2558,190
2061.2.96.0/1961.2.96.1 to 61.2.127.25461.2.127.2558,190
2161.2.128.0/1961.2.128.1 to 61.2.159.25461.2.159.2558,190
2261.2.160.0/1961.2.160.1 to 61.2.191.25461.2.191.2558,190
2361.2.192.0/1961.2.192.1 to 61.2.223.25461.2.223.2558,190
2461.2.224.0/1961.2.224.1 to 61.2.255.25461.2.255.2558,190
2561.3.0.0/1961.3.0.1 to 61.3.31.25461.3.31.2558,190
2661.3.32.0/1961.3.32.1 to 61.3.63.25461.3.63.2558,190
2761.3.64.0/1961.3.64.1 to 61.3.95.25461.3.95.2558,190
2861.3.96.0/1961.3.96.1 to 61.3.127.25461.3.127.2558,190
2961.3.128.0/1961.3.128.1 to 61.3.159.25461.3.159.2558,190
3061.3.160.0/1961.3.160.1 to 61.3.191.25461.3.191.2558,190
3161.3.192.0/1961.3.192.1 to 61.3.223.25461.3.223.2558,190
3261.3.224.0/1961.3.224.1 to 61.3.255.25461.3.255.2558,190
3361.4.0.0/1961.4.0.1 to 61.4.31.25461.4.31.2558,190
3461.4.32.0/1961.4.32.1 to 61.4.63.25461.4.63.2558,190
3561.4.64.0/1961.4.64.1 to 61.4.95.25461.4.95.2558,190
3661.4.96.0/1961.4.96.1 to 61.4.127.25461.4.127.2558,190
3761.4.128.0/1961.4.128.1 to 61.4.159.25461.4.159.2558,190
3861.4.160.0/1961.4.160.1 to 61.4.191.25461.4.191.2558,190
3961.4.192.0/1961.4.192.1 to 61.4.223.25461.4.223.2558,190
4061.4.224.0/1961.4.224.1 to 61.4.255.25461.4.255.2558,190
4161.5.0.0/1961.5.0.1 to 61.5.31.25461.5.31.2558,190
4261.5.32.0/1961.5.32.1 to 61.5.63.25461.5.63.2558,190
4361.5.64.0/1961.5.64.1 to 61.5.95.25461.5.95.2558,190
4461.5.96.0/1961.5.96.1 to 61.5.127.25461.5.127.2558,190
4561.5.128.0/1961.5.128.1 to 61.5.159.25461.5.159.2558,190
4661.5.160.0/1961.5.160.1 to 61.5.191.25461.5.191.2558,190
4761.5.192.0/1961.5.192.1 to 61.5.223.25461.5.223.2558,190
4861.5.224.0/1961.5.224.1 to 61.5.255.25461.5.255.2558,190
4961.6.0.0/1961.6.0.1 to 61.6.31.25461.6.31.2558,190
5061.6.32.0/1961.6.32.1 to 61.6.63.25461.6.63.2558,190
5161.6.64.0/1961.6.64.1 to 61.6.95.25461.6.95.2558,190
5261.6.96.0/1961.6.96.1 to 61.6.127.25461.6.127.2558,190
5361.6.128.0/1961.6.128.1 to 61.6.159.25461.6.159.2558,190
5461.6.160.0/1961.6.160.1 to 61.6.191.25461.6.191.2558,190
5561.6.192.0/1961.6.192.1 to 61.6.223.25461.6.223.2558,190
5661.6.224.0/1961.6.224.1 to 61.6.255.25461.6.255.2558,190
5761.7.0.0/1961.7.0.1 to 61.7.31.25461.7.31.2558,190
5861.7.32.0/1961.7.32.1 to 61.7.63.25461.7.63.2558,190
5961.7.64.0/1961.7.64.1 to 61.7.95.25461.7.95.2558,190
6061.7.96.0/1961.7.96.1 to 61.7.127.25461.7.127.2558,190
6161.7.128.0/1961.7.128.1 to 61.7.159.25461.7.159.2558,190
6261.7.160.0/1961.7.160.1 to 61.7.191.25461.7.191.2558,190
6361.7.192.0/1961.7.192.1 to 61.7.223.25461.7.223.2558,190
6461.7.224.0/1961.7.224.1 to 61.7.255.25461.7.255.2558,190
6561.8.0.0/1961.8.0.1 to 61.8.31.25461.8.31.2558,190
6661.8.32.0/1961.8.32.1 to 61.8.63.25461.8.63.2558,190
6761.8.64.0/1961.8.64.1 to 61.8.95.25461.8.95.2558,190
6861.8.96.0/1961.8.96.1 to 61.8.127.25461.8.127.2558,190
6961.8.128.0/1961.8.128.1 to 61.8.159.25461.8.159.2558,190
7061.8.160.0/1961.8.160.1 to 61.8.191.25461.8.191.2558,190
7161.8.192.0/1961.8.192.1 to 61.8.223.25461.8.223.2558,190
7261.8.224.0/1961.8.224.1 to 61.8.255.25461.8.255.2558,190
7361.9.0.0/1961.9.0.1 to 61.9.31.25461.9.31.2558,190
7461.9.32.0/1961.9.32.1 to 61.9.63.25461.9.63.2558,190
7561.9.64.0/1961.9.64.1 to 61.9.95.25461.9.95.2558,190
7661.9.96.0/1961.9.96.1 to 61.9.127.25461.9.127.2558,190
7761.9.128.0/1961.9.128.1 to 61.9.159.25461.9.159.2558,190
7861.9.160.0/1961.9.160.1 to 61.9.191.25461.9.191.2558,190
7961.9.192.0/1961.9.192.1 to 61.9.223.25461.9.223.2558,190
8061.9.224.0/1961.9.224.1 to 61.9.255.25461.9.255.2558,190
8161.10.0.0/1961.10.0.1 to 61.10.31.25461.10.31.2558,190
8261.10.32.0/1961.10.32.1 to 61.10.63.25461.10.63.2558,190
8361.10.64.0/1961.10.64.1 to 61.10.95.25461.10.95.2558,190
8461.10.96.0/1961.10.96.1 to 61.10.127.25461.10.127.2558,190
8561.10.128.0/1961.10.128.1 to 61.10.159.25461.10.159.2558,190
8661.10.160.0/1961.10.160.1 to 61.10.191.25461.10.191.2558,190
8761.10.192.0/1961.10.192.1 to 61.10.223.25461.10.223.2558,190
8861.10.224.0/1961.10.224.1 to 61.10.255.25461.10.255.2558,190
8961.11.0.0/1961.11.0.1 to 61.11.31.25461.11.31.2558,190
9061.11.32.0/1961.11.32.1 to 61.11.63.25461.11.63.2558,190
9161.11.64.0/1961.11.64.1 to 61.11.95.25461.11.95.2558,190
9261.11.96.0/1961.11.96.1 to 61.11.127.25461.11.127.2558,190
9361.11.128.0/1961.11.128.1 to 61.11.159.25461.11.159.2558,190
9461.11.160.0/1961.11.160.1 to 61.11.191.25461.11.191.2558,190
9561.11.192.0/1961.11.192.1 to 61.11.223.25461.11.223.2558,190
9661.11.224.0/1961.11.224.1 to 61.11.255.25461.11.255.2558,190
9761.12.0.0/1961.12.0.1 to 61.12.31.25461.12.31.2558,190
9861.12.32.0/1961.12.32.1 to 61.12.63.25461.12.63.2558,190
9961.12.64.0/1961.12.64.1 to 61.12.95.25461.12.95.2558,190
10061.12.96.0/1961.12.96.1 to 61.12.127.25461.12.127.2558,190
10161.12.128.0/1961.12.128.1 to 61.12.159.25461.12.159.2558,190
10261.12.160.0/1961.12.160.1 to 61.12.191.25461.12.191.2558,190
10361.12.192.0/1961.12.192.1 to 61.12.223.25461.12.223.2558,190
10461.12.224.0/1961.12.224.1 to 61.12.255.25461.12.255.2558,190
10561.13.0.0/1961.13.0.1 to 61.13.31.25461.13.31.2558,190
10661.13.32.0/1961.13.32.1 to 61.13.63.25461.13.63.2558,190
10761.13.64.0/1961.13.64.1 to 61.13.95.25461.13.95.2558,190
10861.13.96.0/1961.13.96.1 to 61.13.127.25461.13.127.2558,190
10961.13.128.0/1961.13.128.1 to 61.13.159.25461.13.159.2558,190
11061.13.160.0/1961.13.160.1 to 61.13.191.25461.13.191.2558,190
11161.13.192.0/1961.13.192.1 to 61.13.223.25461.13.223.2558,190
11261.13.224.0/1961.13.224.1 to 61.13.255.25461.13.255.2558,190
11361.14.0.0/1961.14.0.1 to 61.14.31.25461.14.31.2558,190
11461.14.32.0/1961.14.32.1 to 61.14.63.25461.14.63.2558,190
11561.14.64.0/1961.14.64.1 to 61.14.95.25461.14.95.2558,190
11661.14.96.0/1961.14.96.1 to 61.14.127.25461.14.127.2558,190
11761.14.128.0/1961.14.128.1 to 61.14.159.25461.14.159.2558,190
11861.14.160.0/1961.14.160.1 to 61.14.191.25461.14.191.2558,190
11961.14.192.0/1961.14.192.1 to 61.14.223.25461.14.223.2558,190
12061.14.224.0/1961.14.224.1 to 61.14.255.25461.14.255.2558,190
12161.15.0.0/1961.15.0.1 to 61.15.31.25461.15.31.2558,190
12261.15.32.0/1961.15.32.1 to 61.15.63.25461.15.63.2558,190
12361.15.64.0/1961.15.64.1 to 61.15.95.25461.15.95.2558,190
12461.15.96.0/1961.15.96.1 to 61.15.127.25461.15.127.2558,190
12561.15.128.0/1961.15.128.1 to 61.15.159.25461.15.159.2558,190
12661.15.160.0/1961.15.160.1 to 61.15.191.25461.15.191.2558,190
12761.15.192.0/1961.15.192.1 to 61.15.223.25461.15.223.2558,190
12861.15.224.0/1961.15.224.1 to 61.15.255.25461.15.255.2558,190
12961.16.0.0/1961.16.0.1 to 61.16.31.25461.16.31.2558,190
13061.16.32.0/1961.16.32.1 to 61.16.63.25461.16.63.2558,190
13161.16.64.0/1961.16.64.1 to 61.16.95.25461.16.95.2558,190
13261.16.96.0/1961.16.96.1 to 61.16.127.25461.16.127.2558,190
13361.16.128.0/1961.16.128.1 to 61.16.159.25461.16.159.2558,190
13461.16.160.0/1961.16.160.1 to 61.16.191.25461.16.191.2558,190
13561.16.192.0/1961.16.192.1 to 61.16.223.25461.16.223.2558,190
13661.16.224.0/1961.16.224.1 to 61.16.255.25461.16.255.2558,190
13761.17.0.0/1961.17.0.1 to 61.17.31.25461.17.31.2558,190
13861.17.32.0/1961.17.32.1 to 61.17.63.25461.17.63.2558,190
13961.17.64.0/1961.17.64.1 to 61.17.95.25461.17.95.2558,190
14061.17.96.0/1961.17.96.1 to 61.17.127.25461.17.127.2558,190
14161.17.128.0/1961.17.128.1 to 61.17.159.25461.17.159.2558,190
14261.17.160.0/1961.17.160.1 to 61.17.191.25461.17.191.2558,190
14361.17.192.0/1961.17.192.1 to 61.17.223.25461.17.223.2558,190
14461.17.224.0/1961.17.224.1 to 61.17.255.25461.17.255.2558,190
14561.18.0.0/1961.18.0.1 to 61.18.31.25461.18.31.2558,190
14661.18.32.0/1961.18.32.1 to 61.18.63.25461.18.63.2558,190
14761.18.64.0/1961.18.64.1 to 61.18.95.25461.18.95.2558,190
14861.18.96.0/1961.18.96.1 to 61.18.127.25461.18.127.2558,190
14961.18.128.0/1961.18.128.1 to 61.18.159.25461.18.159.2558,190
15061.18.160.0/1961.18.160.1 to 61.18.191.25461.18.191.2558,190
15161.18.192.0/1961.18.192.1 to 61.18.223.25461.18.223.2558,190
15261.18.224.0/1961.18.224.1 to 61.18.255.25461.18.255.2558,190
15361.19.0.0/1961.19.0.1 to 61.19.31.25461.19.31.2558,190
15461.19.32.0/1961.19.32.1 to 61.19.63.25461.19.63.2558,190
15561.19.64.0/1961.19.64.1 to 61.19.95.25461.19.95.2558,190
15661.19.96.0/1961.19.96.1 to 61.19.127.25461.19.127.2558,190
15761.19.128.0/1961.19.128.1 to 61.19.159.25461.19.159.2558,190
15861.19.160.0/1961.19.160.1 to 61.19.191.25461.19.191.2558,190
15961.19.192.0/1961.19.192.1 to 61.19.223.25461.19.223.2558,190
16061.19.224.0/1961.19.224.1 to 61.19.255.25461.19.255.2558,190
16161.20.0.0/1961.20.0.1 to 61.20.31.25461.20.31.2558,190
16261.20.32.0/1961.20.32.1 to 61.20.63.25461.20.63.2558,190
16361.20.64.0/1961.20.64.1 to 61.20.95.25461.20.95.2558,190
16461.20.96.0/1961.20.96.1 to 61.20.127.25461.20.127.2558,190
16561.20.128.0/1961.20.128.1 to 61.20.159.25461.20.159.2558,190
16661.20.160.0/1961.20.160.1 to 61.20.191.25461.20.191.2558,190
16761.20.192.0/1961.20.192.1 to 61.20.223.25461.20.223.2558,190
16861.20.224.0/1961.20.224.1 to 61.20.255.25461.20.255.2558,190
16961.21.0.0/1961.21.0.1 to 61.21.31.25461.21.31.2558,190
17061.21.32.0/1961.21.32.1 to 61.21.63.25461.21.63.2558,190
17161.21.64.0/1961.21.64.1 to 61.21.95.25461.21.95.2558,190
17261.21.96.0/1961.21.96.1 to 61.21.127.25461.21.127.2558,190
17361.21.128.0/1961.21.128.1 to 61.21.159.25461.21.159.2558,190
17461.21.160.0/1961.21.160.1 to 61.21.191.25461.21.191.2558,190
17561.21.192.0/1961.21.192.1 to 61.21.223.25461.21.223.2558,190
17661.21.224.0/1961.21.224.1 to 61.21.255.25461.21.255.2558,190
17761.22.0.0/1961.22.0.1 to 61.22.31.25461.22.31.2558,190
17861.22.32.0/1961.22.32.1 to 61.22.63.25461.22.63.2558,190
17961.22.64.0/1961.22.64.1 to 61.22.95.25461.22.95.2558,190
18061.22.96.0/1961.22.96.1 to 61.22.127.25461.22.127.2558,190
18161.22.128.0/1961.22.128.1 to 61.22.159.25461.22.159.2558,190
18261.22.160.0/1961.22.160.1 to 61.22.191.25461.22.191.2558,190
18361.22.192.0/1961.22.192.1 to 61.22.223.25461.22.223.2558,190
18461.22.224.0/1961.22.224.1 to 61.22.255.25461.22.255.2558,190
18561.23.0.0/1961.23.0.1 to 61.23.31.25461.23.31.2558,190
18661.23.32.0/1961.23.32.1 to 61.23.63.25461.23.63.2558,190
18761.23.64.0/1961.23.64.1 to 61.23.95.25461.23.95.2558,190
18861.23.96.0/1961.23.96.1 to 61.23.127.25461.23.127.2558,190
18961.23.128.0/1961.23.128.1 to 61.23.159.25461.23.159.2558,190
19061.23.160.0/1961.23.160.1 to 61.23.191.25461.23.191.2558,190
19161.23.192.0/1961.23.192.1 to 61.23.223.25461.23.223.2558,190
19261.23.224.0/1961.23.224.1 to 61.23.255.25461.23.255.2558,190
19361.24.0.0/1961.24.0.1 to 61.24.31.25461.24.31.2558,190
19461.24.32.0/1961.24.32.1 to 61.24.63.25461.24.63.2558,190
19561.24.64.0/1961.24.64.1 to 61.24.95.25461.24.95.2558,190
19661.24.96.0/1961.24.96.1 to 61.24.127.25461.24.127.2558,190
19761.24.128.0/1961.24.128.1 to 61.24.159.25461.24.159.2558,190
19861.24.160.0/1961.24.160.1 to 61.24.191.25461.24.191.2558,190
19961.24.192.0/1961.24.192.1 to 61.24.223.25461.24.223.2558,190
20061.24.224.0/1961.24.224.1 to 61.24.255.25461.24.255.2558,190
20161.25.0.0/1961.25.0.1 to 61.25.31.25461.25.31.2558,190
20261.25.32.0/1961.25.32.1 to 61.25.63.25461.25.63.2558,190
20361.25.64.0/1961.25.64.1 to 61.25.95.25461.25.95.2558,190
20461.25.96.0/1961.25.96.1 to 61.25.127.25461.25.127.2558,190
20561.25.128.0/1961.25.128.1 to 61.25.159.25461.25.159.2558,190
20661.25.160.0/1961.25.160.1 to 61.25.191.25461.25.191.2558,190
20761.25.192.0/1961.25.192.1 to 61.25.223.25461.25.223.2558,190
20861.25.224.0/1961.25.224.1 to 61.25.255.25461.25.255.2558,190
20961.26.0.0/1961.26.0.1 to 61.26.31.25461.26.31.2558,190
21061.26.32.0/1961.26.32.1 to 61.26.63.25461.26.63.2558,190
21161.26.64.0/1961.26.64.1 to 61.26.95.25461.26.95.2558,190
21261.26.96.0/1961.26.96.1 to 61.26.127.25461.26.127.2558,190
21361.26.128.0/1961.26.128.1 to 61.26.159.25461.26.159.2558,190
21461.26.160.0/1961.26.160.1 to 61.26.191.25461.26.191.2558,190
21561.26.192.0/1961.26.192.1 to 61.26.223.25461.26.223.2558,190
21661.26.224.0/1961.26.224.1 to 61.26.255.25461.26.255.2558,190
21761.27.0.0/1961.27.0.1 to 61.27.31.25461.27.31.2558,190
21861.27.32.0/1961.27.32.1 to 61.27.63.25461.27.63.2558,190
21961.27.64.0/1961.27.64.1 to 61.27.95.25461.27.95.2558,190
22061.27.96.0/1961.27.96.1 to 61.27.127.25461.27.127.2558,190
22161.27.128.0/1961.27.128.1 to 61.27.159.25461.27.159.2558,190
22261.27.160.0/1961.27.160.1 to 61.27.191.25461.27.191.2558,190
22361.27.192.0/1961.27.192.1 to 61.27.223.25461.27.223.2558,190
22461.27.224.0/1961.27.224.1 to 61.27.255.25461.27.255.2558,190
22561.28.0.0/1961.28.0.1 to 61.28.31.25461.28.31.2558,190
22661.28.32.0/1961.28.32.1 to 61.28.63.25461.28.63.2558,190
22761.28.64.0/1961.28.64.1 to 61.28.95.25461.28.95.2558,190
22861.28.96.0/1961.28.96.1 to 61.28.127.25461.28.127.2558,190
22961.28.128.0/1961.28.128.1 to 61.28.159.25461.28.159.2558,190
23061.28.160.0/1961.28.160.1 to 61.28.191.25461.28.191.2558,190
23161.28.192.0/1961.28.192.1 to 61.28.223.25461.28.223.2558,190
23261.28.224.0/1961.28.224.1 to 61.28.255.25461.28.255.2558,190
23361.29.0.0/1961.29.0.1 to 61.29.31.25461.29.31.2558,190
23461.29.32.0/1961.29.32.1 to 61.29.63.25461.29.63.2558,190
23561.29.64.0/1961.29.64.1 to 61.29.95.25461.29.95.2558,190
23661.29.96.0/1961.29.96.1 to 61.29.127.25461.29.127.2558,190
23761.29.128.0/1961.29.128.1 to 61.29.159.25461.29.159.2558,190
23861.29.160.0/1961.29.160.1 to 61.29.191.25461.29.191.2558,190
23961.29.192.0/1961.29.192.1 to 61.29.223.25461.29.223.2558,190
24061.29.224.0/1961.29.224.1 to 61.29.255.25461.29.255.2558,190
24161.30.0.0/1961.30.0.1 to 61.30.31.25461.30.31.2558,190
24261.30.32.0/1961.30.32.1 to 61.30.63.25461.30.63.2558,190
24361.30.64.0/1961.30.64.1 to 61.30.95.25461.30.95.2558,190
24461.30.96.0/1961.30.96.1 to 61.30.127.25461.30.127.2558,190
24561.30.128.0/1961.30.128.1 to 61.30.159.25461.30.159.2558,190
24661.30.160.0/1961.30.160.1 to 61.30.191.25461.30.191.2558,190
24761.30.192.0/1961.30.192.1 to 61.30.223.25461.30.223.2558,190
24861.30.224.0/1961.30.224.1 to 61.30.255.25461.30.255.2558,190
24961.31.0.0/1961.31.0.1 to 61.31.31.25461.31.31.2558,190
25061.31.32.0/1961.31.32.1 to 61.31.63.25461.31.63.2558,190
25161.31.64.0/1961.31.64.1 to 61.31.95.25461.31.95.2558,190
25261.31.96.0/1961.31.96.1 to 61.31.127.25461.31.127.2558,190
25361.31.128.0/1961.31.128.1 to 61.31.159.25461.31.159.2558,190
25461.31.160.0/1961.31.160.1 to 61.31.191.25461.31.191.2558,190
25561.31.192.0/1961.31.192.1 to 61.31.223.25461.31.223.2558,190
25661.31.224.0/1961.31.224.1 to 61.31.255.25461.31.255.2558,190

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.