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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.

Network97.0.0.0/9
Usable hosts8,388,606
Subnet mask255.128.0.0
Addresses8,388,608
Network address
97.0.0.0
Broadcast address
97.127.255.255
First usable
97.0.0.1
Last usable
97.127.255.254
Usable hosts
8,388,606 (8,388,608 less the network and broadcast addresses)
Subnet mask
255.128.0.0
Wildcard mask
0.127.255.255 (Cisco ACLs, OSPF)
Prefix length
/9
Type
Public public
Old class
A (default /8)
As numbers
Hex 61000000 · Integer 1627389952 to 1635778559
Reverse DNS zones
0.97.in-addr.arpa
1.97.in-addr.arpa
2.97.in-addr.arpa
3.97.in-addr.arpa
4.97.in-addr.arpa
5.97.in-addr.arpa
6.97.in-addr.arpa
7.97.in-addr.arpa
8.97.in-addr.arpa
9.97.in-addr.arpa
10.97.in-addr.arpa
11.97.in-addr.arpa
12.97.in-addr.arpa
13.97.in-addr.arpa
14.97.in-addr.arpa
15.97.in-addr.arpa
and 112 more
/9 is not on a 8-bit boundary, so it takes 128 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01100001.00000000.00000000.0000000097.0.0.0
Subnet mask11111111.10000000.00000000.00000000255.128.0.0
Network01100001.00000000.00000000.0000000097.0.0.0
Broadcast01100001.01111111.11111111.1111111197.127.255.255
Split into smaller subnets/19
/10 (2)/11 (4)/12 (8)/13 (16)/14 (32)/15 (64)/16 (128)/17 (256)/18 (512)/19 (1,024)/20 (2,048)/21 (4,096)

97.0.0.0/9 makes 1,024 subnets of /19; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
197.0.0.0/1997.0.0.1 to 97.0.31.25497.0.31.2558,190
297.0.32.0/1997.0.32.1 to 97.0.63.25497.0.63.2558,190
397.0.64.0/1997.0.64.1 to 97.0.95.25497.0.95.2558,190
497.0.96.0/1997.0.96.1 to 97.0.127.25497.0.127.2558,190
597.0.128.0/1997.0.128.1 to 97.0.159.25497.0.159.2558,190
697.0.160.0/1997.0.160.1 to 97.0.191.25497.0.191.2558,190
797.0.192.0/1997.0.192.1 to 97.0.223.25497.0.223.2558,190
897.0.224.0/1997.0.224.1 to 97.0.255.25497.0.255.2558,190
997.1.0.0/1997.1.0.1 to 97.1.31.25497.1.31.2558,190
1097.1.32.0/1997.1.32.1 to 97.1.63.25497.1.63.2558,190
1197.1.64.0/1997.1.64.1 to 97.1.95.25497.1.95.2558,190
1297.1.96.0/1997.1.96.1 to 97.1.127.25497.1.127.2558,190
1397.1.128.0/1997.1.128.1 to 97.1.159.25497.1.159.2558,190
1497.1.160.0/1997.1.160.1 to 97.1.191.25497.1.191.2558,190
1597.1.192.0/1997.1.192.1 to 97.1.223.25497.1.223.2558,190
1697.1.224.0/1997.1.224.1 to 97.1.255.25497.1.255.2558,190
1797.2.0.0/1997.2.0.1 to 97.2.31.25497.2.31.2558,190
1897.2.32.0/1997.2.32.1 to 97.2.63.25497.2.63.2558,190
1997.2.64.0/1997.2.64.1 to 97.2.95.25497.2.95.2558,190
2097.2.96.0/1997.2.96.1 to 97.2.127.25497.2.127.2558,190
2197.2.128.0/1997.2.128.1 to 97.2.159.25497.2.159.2558,190
2297.2.160.0/1997.2.160.1 to 97.2.191.25497.2.191.2558,190
2397.2.192.0/1997.2.192.1 to 97.2.223.25497.2.223.2558,190
2497.2.224.0/1997.2.224.1 to 97.2.255.25497.2.255.2558,190
2597.3.0.0/1997.3.0.1 to 97.3.31.25497.3.31.2558,190
2697.3.32.0/1997.3.32.1 to 97.3.63.25497.3.63.2558,190
2797.3.64.0/1997.3.64.1 to 97.3.95.25497.3.95.2558,190
2897.3.96.0/1997.3.96.1 to 97.3.127.25497.3.127.2558,190
2997.3.128.0/1997.3.128.1 to 97.3.159.25497.3.159.2558,190
3097.3.160.0/1997.3.160.1 to 97.3.191.25497.3.191.2558,190
3197.3.192.0/1997.3.192.1 to 97.3.223.25497.3.223.2558,190
3297.3.224.0/1997.3.224.1 to 97.3.255.25497.3.255.2558,190
3397.4.0.0/1997.4.0.1 to 97.4.31.25497.4.31.2558,190
3497.4.32.0/1997.4.32.1 to 97.4.63.25497.4.63.2558,190
3597.4.64.0/1997.4.64.1 to 97.4.95.25497.4.95.2558,190
3697.4.96.0/1997.4.96.1 to 97.4.127.25497.4.127.2558,190
3797.4.128.0/1997.4.128.1 to 97.4.159.25497.4.159.2558,190
3897.4.160.0/1997.4.160.1 to 97.4.191.25497.4.191.2558,190
3997.4.192.0/1997.4.192.1 to 97.4.223.25497.4.223.2558,190
4097.4.224.0/1997.4.224.1 to 97.4.255.25497.4.255.2558,190
4197.5.0.0/1997.5.0.1 to 97.5.31.25497.5.31.2558,190
4297.5.32.0/1997.5.32.1 to 97.5.63.25497.5.63.2558,190
4397.5.64.0/1997.5.64.1 to 97.5.95.25497.5.95.2558,190
4497.5.96.0/1997.5.96.1 to 97.5.127.25497.5.127.2558,190
4597.5.128.0/1997.5.128.1 to 97.5.159.25497.5.159.2558,190
4697.5.160.0/1997.5.160.1 to 97.5.191.25497.5.191.2558,190
4797.5.192.0/1997.5.192.1 to 97.5.223.25497.5.223.2558,190
4897.5.224.0/1997.5.224.1 to 97.5.255.25497.5.255.2558,190
4997.6.0.0/1997.6.0.1 to 97.6.31.25497.6.31.2558,190
5097.6.32.0/1997.6.32.1 to 97.6.63.25497.6.63.2558,190
5197.6.64.0/1997.6.64.1 to 97.6.95.25497.6.95.2558,190
5297.6.96.0/1997.6.96.1 to 97.6.127.25497.6.127.2558,190
5397.6.128.0/1997.6.128.1 to 97.6.159.25497.6.159.2558,190
5497.6.160.0/1997.6.160.1 to 97.6.191.25497.6.191.2558,190
5597.6.192.0/1997.6.192.1 to 97.6.223.25497.6.223.2558,190
5697.6.224.0/1997.6.224.1 to 97.6.255.25497.6.255.2558,190
5797.7.0.0/1997.7.0.1 to 97.7.31.25497.7.31.2558,190
5897.7.32.0/1997.7.32.1 to 97.7.63.25497.7.63.2558,190
5997.7.64.0/1997.7.64.1 to 97.7.95.25497.7.95.2558,190
6097.7.96.0/1997.7.96.1 to 97.7.127.25497.7.127.2558,190
6197.7.128.0/1997.7.128.1 to 97.7.159.25497.7.159.2558,190
6297.7.160.0/1997.7.160.1 to 97.7.191.25497.7.191.2558,190
6397.7.192.0/1997.7.192.1 to 97.7.223.25497.7.223.2558,190
6497.7.224.0/1997.7.224.1 to 97.7.255.25497.7.255.2558,190
6597.8.0.0/1997.8.0.1 to 97.8.31.25497.8.31.2558,190
6697.8.32.0/1997.8.32.1 to 97.8.63.25497.8.63.2558,190
6797.8.64.0/1997.8.64.1 to 97.8.95.25497.8.95.2558,190
6897.8.96.0/1997.8.96.1 to 97.8.127.25497.8.127.2558,190
6997.8.128.0/1997.8.128.1 to 97.8.159.25497.8.159.2558,190
7097.8.160.0/1997.8.160.1 to 97.8.191.25497.8.191.2558,190
7197.8.192.0/1997.8.192.1 to 97.8.223.25497.8.223.2558,190
7297.8.224.0/1997.8.224.1 to 97.8.255.25497.8.255.2558,190
7397.9.0.0/1997.9.0.1 to 97.9.31.25497.9.31.2558,190
7497.9.32.0/1997.9.32.1 to 97.9.63.25497.9.63.2558,190
7597.9.64.0/1997.9.64.1 to 97.9.95.25497.9.95.2558,190
7697.9.96.0/1997.9.96.1 to 97.9.127.25497.9.127.2558,190
7797.9.128.0/1997.9.128.1 to 97.9.159.25497.9.159.2558,190
7897.9.160.0/1997.9.160.1 to 97.9.191.25497.9.191.2558,190
7997.9.192.0/1997.9.192.1 to 97.9.223.25497.9.223.2558,190
8097.9.224.0/1997.9.224.1 to 97.9.255.25497.9.255.2558,190
8197.10.0.0/1997.10.0.1 to 97.10.31.25497.10.31.2558,190
8297.10.32.0/1997.10.32.1 to 97.10.63.25497.10.63.2558,190
8397.10.64.0/1997.10.64.1 to 97.10.95.25497.10.95.2558,190
8497.10.96.0/1997.10.96.1 to 97.10.127.25497.10.127.2558,190
8597.10.128.0/1997.10.128.1 to 97.10.159.25497.10.159.2558,190
8697.10.160.0/1997.10.160.1 to 97.10.191.25497.10.191.2558,190
8797.10.192.0/1997.10.192.1 to 97.10.223.25497.10.223.2558,190
8897.10.224.0/1997.10.224.1 to 97.10.255.25497.10.255.2558,190
8997.11.0.0/1997.11.0.1 to 97.11.31.25497.11.31.2558,190
9097.11.32.0/1997.11.32.1 to 97.11.63.25497.11.63.2558,190
9197.11.64.0/1997.11.64.1 to 97.11.95.25497.11.95.2558,190
9297.11.96.0/1997.11.96.1 to 97.11.127.25497.11.127.2558,190
9397.11.128.0/1997.11.128.1 to 97.11.159.25497.11.159.2558,190
9497.11.160.0/1997.11.160.1 to 97.11.191.25497.11.191.2558,190
9597.11.192.0/1997.11.192.1 to 97.11.223.25497.11.223.2558,190
9697.11.224.0/1997.11.224.1 to 97.11.255.25497.11.255.2558,190
9797.12.0.0/1997.12.0.1 to 97.12.31.25497.12.31.2558,190
9897.12.32.0/1997.12.32.1 to 97.12.63.25497.12.63.2558,190
9997.12.64.0/1997.12.64.1 to 97.12.95.25497.12.95.2558,190
10097.12.96.0/1997.12.96.1 to 97.12.127.25497.12.127.2558,190
10197.12.128.0/1997.12.128.1 to 97.12.159.25497.12.159.2558,190
10297.12.160.0/1997.12.160.1 to 97.12.191.25497.12.191.2558,190
10397.12.192.0/1997.12.192.1 to 97.12.223.25497.12.223.2558,190
10497.12.224.0/1997.12.224.1 to 97.12.255.25497.12.255.2558,190
10597.13.0.0/1997.13.0.1 to 97.13.31.25497.13.31.2558,190
10697.13.32.0/1997.13.32.1 to 97.13.63.25497.13.63.2558,190
10797.13.64.0/1997.13.64.1 to 97.13.95.25497.13.95.2558,190
10897.13.96.0/1997.13.96.1 to 97.13.127.25497.13.127.2558,190
10997.13.128.0/1997.13.128.1 to 97.13.159.25497.13.159.2558,190
11097.13.160.0/1997.13.160.1 to 97.13.191.25497.13.191.2558,190
11197.13.192.0/1997.13.192.1 to 97.13.223.25497.13.223.2558,190
11297.13.224.0/1997.13.224.1 to 97.13.255.25497.13.255.2558,190
11397.14.0.0/1997.14.0.1 to 97.14.31.25497.14.31.2558,190
11497.14.32.0/1997.14.32.1 to 97.14.63.25497.14.63.2558,190
11597.14.64.0/1997.14.64.1 to 97.14.95.25497.14.95.2558,190
11697.14.96.0/1997.14.96.1 to 97.14.127.25497.14.127.2558,190
11797.14.128.0/1997.14.128.1 to 97.14.159.25497.14.159.2558,190
11897.14.160.0/1997.14.160.1 to 97.14.191.25497.14.191.2558,190
11997.14.192.0/1997.14.192.1 to 97.14.223.25497.14.223.2558,190
12097.14.224.0/1997.14.224.1 to 97.14.255.25497.14.255.2558,190
12197.15.0.0/1997.15.0.1 to 97.15.31.25497.15.31.2558,190
12297.15.32.0/1997.15.32.1 to 97.15.63.25497.15.63.2558,190
12397.15.64.0/1997.15.64.1 to 97.15.95.25497.15.95.2558,190
12497.15.96.0/1997.15.96.1 to 97.15.127.25497.15.127.2558,190
12597.15.128.0/1997.15.128.1 to 97.15.159.25497.15.159.2558,190
12697.15.160.0/1997.15.160.1 to 97.15.191.25497.15.191.2558,190
12797.15.192.0/1997.15.192.1 to 97.15.223.25497.15.223.2558,190
12897.15.224.0/1997.15.224.1 to 97.15.255.25497.15.255.2558,190
12997.16.0.0/1997.16.0.1 to 97.16.31.25497.16.31.2558,190
13097.16.32.0/1997.16.32.1 to 97.16.63.25497.16.63.2558,190
13197.16.64.0/1997.16.64.1 to 97.16.95.25497.16.95.2558,190
13297.16.96.0/1997.16.96.1 to 97.16.127.25497.16.127.2558,190
13397.16.128.0/1997.16.128.1 to 97.16.159.25497.16.159.2558,190
13497.16.160.0/1997.16.160.1 to 97.16.191.25497.16.191.2558,190
13597.16.192.0/1997.16.192.1 to 97.16.223.25497.16.223.2558,190
13697.16.224.0/1997.16.224.1 to 97.16.255.25497.16.255.2558,190
13797.17.0.0/1997.17.0.1 to 97.17.31.25497.17.31.2558,190
13897.17.32.0/1997.17.32.1 to 97.17.63.25497.17.63.2558,190
13997.17.64.0/1997.17.64.1 to 97.17.95.25497.17.95.2558,190
14097.17.96.0/1997.17.96.1 to 97.17.127.25497.17.127.2558,190
14197.17.128.0/1997.17.128.1 to 97.17.159.25497.17.159.2558,190
14297.17.160.0/1997.17.160.1 to 97.17.191.25497.17.191.2558,190
14397.17.192.0/1997.17.192.1 to 97.17.223.25497.17.223.2558,190
14497.17.224.0/1997.17.224.1 to 97.17.255.25497.17.255.2558,190
14597.18.0.0/1997.18.0.1 to 97.18.31.25497.18.31.2558,190
14697.18.32.0/1997.18.32.1 to 97.18.63.25497.18.63.2558,190
14797.18.64.0/1997.18.64.1 to 97.18.95.25497.18.95.2558,190
14897.18.96.0/1997.18.96.1 to 97.18.127.25497.18.127.2558,190
14997.18.128.0/1997.18.128.1 to 97.18.159.25497.18.159.2558,190
15097.18.160.0/1997.18.160.1 to 97.18.191.25497.18.191.2558,190
15197.18.192.0/1997.18.192.1 to 97.18.223.25497.18.223.2558,190
15297.18.224.0/1997.18.224.1 to 97.18.255.25497.18.255.2558,190
15397.19.0.0/1997.19.0.1 to 97.19.31.25497.19.31.2558,190
15497.19.32.0/1997.19.32.1 to 97.19.63.25497.19.63.2558,190
15597.19.64.0/1997.19.64.1 to 97.19.95.25497.19.95.2558,190
15697.19.96.0/1997.19.96.1 to 97.19.127.25497.19.127.2558,190
15797.19.128.0/1997.19.128.1 to 97.19.159.25497.19.159.2558,190
15897.19.160.0/1997.19.160.1 to 97.19.191.25497.19.191.2558,190
15997.19.192.0/1997.19.192.1 to 97.19.223.25497.19.223.2558,190
16097.19.224.0/1997.19.224.1 to 97.19.255.25497.19.255.2558,190
16197.20.0.0/1997.20.0.1 to 97.20.31.25497.20.31.2558,190
16297.20.32.0/1997.20.32.1 to 97.20.63.25497.20.63.2558,190
16397.20.64.0/1997.20.64.1 to 97.20.95.25497.20.95.2558,190
16497.20.96.0/1997.20.96.1 to 97.20.127.25497.20.127.2558,190
16597.20.128.0/1997.20.128.1 to 97.20.159.25497.20.159.2558,190
16697.20.160.0/1997.20.160.1 to 97.20.191.25497.20.191.2558,190
16797.20.192.0/1997.20.192.1 to 97.20.223.25497.20.223.2558,190
16897.20.224.0/1997.20.224.1 to 97.20.255.25497.20.255.2558,190
16997.21.0.0/1997.21.0.1 to 97.21.31.25497.21.31.2558,190
17097.21.32.0/1997.21.32.1 to 97.21.63.25497.21.63.2558,190
17197.21.64.0/1997.21.64.1 to 97.21.95.25497.21.95.2558,190
17297.21.96.0/1997.21.96.1 to 97.21.127.25497.21.127.2558,190
17397.21.128.0/1997.21.128.1 to 97.21.159.25497.21.159.2558,190
17497.21.160.0/1997.21.160.1 to 97.21.191.25497.21.191.2558,190
17597.21.192.0/1997.21.192.1 to 97.21.223.25497.21.223.2558,190
17697.21.224.0/1997.21.224.1 to 97.21.255.25497.21.255.2558,190
17797.22.0.0/1997.22.0.1 to 97.22.31.25497.22.31.2558,190
17897.22.32.0/1997.22.32.1 to 97.22.63.25497.22.63.2558,190
17997.22.64.0/1997.22.64.1 to 97.22.95.25497.22.95.2558,190
18097.22.96.0/1997.22.96.1 to 97.22.127.25497.22.127.2558,190
18197.22.128.0/1997.22.128.1 to 97.22.159.25497.22.159.2558,190
18297.22.160.0/1997.22.160.1 to 97.22.191.25497.22.191.2558,190
18397.22.192.0/1997.22.192.1 to 97.22.223.25497.22.223.2558,190
18497.22.224.0/1997.22.224.1 to 97.22.255.25497.22.255.2558,190
18597.23.0.0/1997.23.0.1 to 97.23.31.25497.23.31.2558,190
18697.23.32.0/1997.23.32.1 to 97.23.63.25497.23.63.2558,190
18797.23.64.0/1997.23.64.1 to 97.23.95.25497.23.95.2558,190
18897.23.96.0/1997.23.96.1 to 97.23.127.25497.23.127.2558,190
18997.23.128.0/1997.23.128.1 to 97.23.159.25497.23.159.2558,190
19097.23.160.0/1997.23.160.1 to 97.23.191.25497.23.191.2558,190
19197.23.192.0/1997.23.192.1 to 97.23.223.25497.23.223.2558,190
19297.23.224.0/1997.23.224.1 to 97.23.255.25497.23.255.2558,190
19397.24.0.0/1997.24.0.1 to 97.24.31.25497.24.31.2558,190
19497.24.32.0/1997.24.32.1 to 97.24.63.25497.24.63.2558,190
19597.24.64.0/1997.24.64.1 to 97.24.95.25497.24.95.2558,190
19697.24.96.0/1997.24.96.1 to 97.24.127.25497.24.127.2558,190
19797.24.128.0/1997.24.128.1 to 97.24.159.25497.24.159.2558,190
19897.24.160.0/1997.24.160.1 to 97.24.191.25497.24.191.2558,190
19997.24.192.0/1997.24.192.1 to 97.24.223.25497.24.223.2558,190
20097.24.224.0/1997.24.224.1 to 97.24.255.25497.24.255.2558,190
20197.25.0.0/1997.25.0.1 to 97.25.31.25497.25.31.2558,190
20297.25.32.0/1997.25.32.1 to 97.25.63.25497.25.63.2558,190
20397.25.64.0/1997.25.64.1 to 97.25.95.25497.25.95.2558,190
20497.25.96.0/1997.25.96.1 to 97.25.127.25497.25.127.2558,190
20597.25.128.0/1997.25.128.1 to 97.25.159.25497.25.159.2558,190
20697.25.160.0/1997.25.160.1 to 97.25.191.25497.25.191.2558,190
20797.25.192.0/1997.25.192.1 to 97.25.223.25497.25.223.2558,190
20897.25.224.0/1997.25.224.1 to 97.25.255.25497.25.255.2558,190
20997.26.0.0/1997.26.0.1 to 97.26.31.25497.26.31.2558,190
21097.26.32.0/1997.26.32.1 to 97.26.63.25497.26.63.2558,190
21197.26.64.0/1997.26.64.1 to 97.26.95.25497.26.95.2558,190
21297.26.96.0/1997.26.96.1 to 97.26.127.25497.26.127.2558,190
21397.26.128.0/1997.26.128.1 to 97.26.159.25497.26.159.2558,190
21497.26.160.0/1997.26.160.1 to 97.26.191.25497.26.191.2558,190
21597.26.192.0/1997.26.192.1 to 97.26.223.25497.26.223.2558,190
21697.26.224.0/1997.26.224.1 to 97.26.255.25497.26.255.2558,190
21797.27.0.0/1997.27.0.1 to 97.27.31.25497.27.31.2558,190
21897.27.32.0/1997.27.32.1 to 97.27.63.25497.27.63.2558,190
21997.27.64.0/1997.27.64.1 to 97.27.95.25497.27.95.2558,190
22097.27.96.0/1997.27.96.1 to 97.27.127.25497.27.127.2558,190
22197.27.128.0/1997.27.128.1 to 97.27.159.25497.27.159.2558,190
22297.27.160.0/1997.27.160.1 to 97.27.191.25497.27.191.2558,190
22397.27.192.0/1997.27.192.1 to 97.27.223.25497.27.223.2558,190
22497.27.224.0/1997.27.224.1 to 97.27.255.25497.27.255.2558,190
22597.28.0.0/1997.28.0.1 to 97.28.31.25497.28.31.2558,190
22697.28.32.0/1997.28.32.1 to 97.28.63.25497.28.63.2558,190
22797.28.64.0/1997.28.64.1 to 97.28.95.25497.28.95.2558,190
22897.28.96.0/1997.28.96.1 to 97.28.127.25497.28.127.2558,190
22997.28.128.0/1997.28.128.1 to 97.28.159.25497.28.159.2558,190
23097.28.160.0/1997.28.160.1 to 97.28.191.25497.28.191.2558,190
23197.28.192.0/1997.28.192.1 to 97.28.223.25497.28.223.2558,190
23297.28.224.0/1997.28.224.1 to 97.28.255.25497.28.255.2558,190
23397.29.0.0/1997.29.0.1 to 97.29.31.25497.29.31.2558,190
23497.29.32.0/1997.29.32.1 to 97.29.63.25497.29.63.2558,190
23597.29.64.0/1997.29.64.1 to 97.29.95.25497.29.95.2558,190
23697.29.96.0/1997.29.96.1 to 97.29.127.25497.29.127.2558,190
23797.29.128.0/1997.29.128.1 to 97.29.159.25497.29.159.2558,190
23897.29.160.0/1997.29.160.1 to 97.29.191.25497.29.191.2558,190
23997.29.192.0/1997.29.192.1 to 97.29.223.25497.29.223.2558,190
24097.29.224.0/1997.29.224.1 to 97.29.255.25497.29.255.2558,190
24197.30.0.0/1997.30.0.1 to 97.30.31.25497.30.31.2558,190
24297.30.32.0/1997.30.32.1 to 97.30.63.25497.30.63.2558,190
24397.30.64.0/1997.30.64.1 to 97.30.95.25497.30.95.2558,190
24497.30.96.0/1997.30.96.1 to 97.30.127.25497.30.127.2558,190
24597.30.128.0/1997.30.128.1 to 97.30.159.25497.30.159.2558,190
24697.30.160.0/1997.30.160.1 to 97.30.191.25497.30.191.2558,190
24797.30.192.0/1997.30.192.1 to 97.30.223.25497.30.223.2558,190
24897.30.224.0/1997.30.224.1 to 97.30.255.25497.30.255.2558,190
24997.31.0.0/1997.31.0.1 to 97.31.31.25497.31.31.2558,190
25097.31.32.0/1997.31.32.1 to 97.31.63.25497.31.63.2558,190
25197.31.64.0/1997.31.64.1 to 97.31.95.25497.31.95.2558,190
25297.31.96.0/1997.31.96.1 to 97.31.127.25497.31.127.2558,190
25397.31.128.0/1997.31.128.1 to 97.31.159.25497.31.159.2558,190
25497.31.160.0/1997.31.160.1 to 97.31.191.25497.31.191.2558,190
25597.31.192.0/1997.31.192.1 to 97.31.223.25497.31.223.2558,190
25697.31.224.0/1997.31.224.1 to 97.31.255.25497.31.255.2558,190

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.