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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.

Network79.0.0.0/9
Usable hosts8,388,606
Subnet mask255.128.0.0
Addresses8,388,608
Network address
79.0.0.0
Broadcast address
79.127.255.255
First usable
79.0.0.1
Last usable
79.127.255.254
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 4F000000 · Integer 1325400064 to 1333788671
Reverse DNS zones
0.79.in-addr.arpa
1.79.in-addr.arpa
2.79.in-addr.arpa
3.79.in-addr.arpa
4.79.in-addr.arpa
5.79.in-addr.arpa
6.79.in-addr.arpa
7.79.in-addr.arpa
8.79.in-addr.arpa
9.79.in-addr.arpa
10.79.in-addr.arpa
11.79.in-addr.arpa
12.79.in-addr.arpa
13.79.in-addr.arpa
14.79.in-addr.arpa
15.79.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
Address01001111.00000000.00000000.0000000079.0.0.0
Subnet mask11111111.10000000.00000000.00000000255.128.0.0
Network01001111.00000000.00000000.0000000079.0.0.0
Broadcast01001111.01111111.11111111.1111111179.127.255.255
Split into smaller subnets/18
/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)

79.0.0.0/9 makes 512 subnets of /18; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
179.0.0.0/1879.0.0.1 to 79.0.63.25479.0.63.25516,382
279.0.64.0/1879.0.64.1 to 79.0.127.25479.0.127.25516,382
379.0.128.0/1879.0.128.1 to 79.0.191.25479.0.191.25516,382
479.0.192.0/1879.0.192.1 to 79.0.255.25479.0.255.25516,382
579.1.0.0/1879.1.0.1 to 79.1.63.25479.1.63.25516,382
679.1.64.0/1879.1.64.1 to 79.1.127.25479.1.127.25516,382
779.1.128.0/1879.1.128.1 to 79.1.191.25479.1.191.25516,382
879.1.192.0/1879.1.192.1 to 79.1.255.25479.1.255.25516,382
979.2.0.0/1879.2.0.1 to 79.2.63.25479.2.63.25516,382
1079.2.64.0/1879.2.64.1 to 79.2.127.25479.2.127.25516,382
1179.2.128.0/1879.2.128.1 to 79.2.191.25479.2.191.25516,382
1279.2.192.0/1879.2.192.1 to 79.2.255.25479.2.255.25516,382
1379.3.0.0/1879.3.0.1 to 79.3.63.25479.3.63.25516,382
1479.3.64.0/1879.3.64.1 to 79.3.127.25479.3.127.25516,382
1579.3.128.0/1879.3.128.1 to 79.3.191.25479.3.191.25516,382
1679.3.192.0/1879.3.192.1 to 79.3.255.25479.3.255.25516,382
1779.4.0.0/1879.4.0.1 to 79.4.63.25479.4.63.25516,382
1879.4.64.0/1879.4.64.1 to 79.4.127.25479.4.127.25516,382
1979.4.128.0/1879.4.128.1 to 79.4.191.25479.4.191.25516,382
2079.4.192.0/1879.4.192.1 to 79.4.255.25479.4.255.25516,382
2179.5.0.0/1879.5.0.1 to 79.5.63.25479.5.63.25516,382
2279.5.64.0/1879.5.64.1 to 79.5.127.25479.5.127.25516,382
2379.5.128.0/1879.5.128.1 to 79.5.191.25479.5.191.25516,382
2479.5.192.0/1879.5.192.1 to 79.5.255.25479.5.255.25516,382
2579.6.0.0/1879.6.0.1 to 79.6.63.25479.6.63.25516,382
2679.6.64.0/1879.6.64.1 to 79.6.127.25479.6.127.25516,382
2779.6.128.0/1879.6.128.1 to 79.6.191.25479.6.191.25516,382
2879.6.192.0/1879.6.192.1 to 79.6.255.25479.6.255.25516,382
2979.7.0.0/1879.7.0.1 to 79.7.63.25479.7.63.25516,382
3079.7.64.0/1879.7.64.1 to 79.7.127.25479.7.127.25516,382
3179.7.128.0/1879.7.128.1 to 79.7.191.25479.7.191.25516,382
3279.7.192.0/1879.7.192.1 to 79.7.255.25479.7.255.25516,382
3379.8.0.0/1879.8.0.1 to 79.8.63.25479.8.63.25516,382
3479.8.64.0/1879.8.64.1 to 79.8.127.25479.8.127.25516,382
3579.8.128.0/1879.8.128.1 to 79.8.191.25479.8.191.25516,382
3679.8.192.0/1879.8.192.1 to 79.8.255.25479.8.255.25516,382
3779.9.0.0/1879.9.0.1 to 79.9.63.25479.9.63.25516,382
3879.9.64.0/1879.9.64.1 to 79.9.127.25479.9.127.25516,382
3979.9.128.0/1879.9.128.1 to 79.9.191.25479.9.191.25516,382
4079.9.192.0/1879.9.192.1 to 79.9.255.25479.9.255.25516,382
4179.10.0.0/1879.10.0.1 to 79.10.63.25479.10.63.25516,382
4279.10.64.0/1879.10.64.1 to 79.10.127.25479.10.127.25516,382
4379.10.128.0/1879.10.128.1 to 79.10.191.25479.10.191.25516,382
4479.10.192.0/1879.10.192.1 to 79.10.255.25479.10.255.25516,382
4579.11.0.0/1879.11.0.1 to 79.11.63.25479.11.63.25516,382
4679.11.64.0/1879.11.64.1 to 79.11.127.25479.11.127.25516,382
4779.11.128.0/1879.11.128.1 to 79.11.191.25479.11.191.25516,382
4879.11.192.0/1879.11.192.1 to 79.11.255.25479.11.255.25516,382
4979.12.0.0/1879.12.0.1 to 79.12.63.25479.12.63.25516,382
5079.12.64.0/1879.12.64.1 to 79.12.127.25479.12.127.25516,382
5179.12.128.0/1879.12.128.1 to 79.12.191.25479.12.191.25516,382
5279.12.192.0/1879.12.192.1 to 79.12.255.25479.12.255.25516,382
5379.13.0.0/1879.13.0.1 to 79.13.63.25479.13.63.25516,382
5479.13.64.0/1879.13.64.1 to 79.13.127.25479.13.127.25516,382
5579.13.128.0/1879.13.128.1 to 79.13.191.25479.13.191.25516,382
5679.13.192.0/1879.13.192.1 to 79.13.255.25479.13.255.25516,382
5779.14.0.0/1879.14.0.1 to 79.14.63.25479.14.63.25516,382
5879.14.64.0/1879.14.64.1 to 79.14.127.25479.14.127.25516,382
5979.14.128.0/1879.14.128.1 to 79.14.191.25479.14.191.25516,382
6079.14.192.0/1879.14.192.1 to 79.14.255.25479.14.255.25516,382
6179.15.0.0/1879.15.0.1 to 79.15.63.25479.15.63.25516,382
6279.15.64.0/1879.15.64.1 to 79.15.127.25479.15.127.25516,382
6379.15.128.0/1879.15.128.1 to 79.15.191.25479.15.191.25516,382
6479.15.192.0/1879.15.192.1 to 79.15.255.25479.15.255.25516,382
6579.16.0.0/1879.16.0.1 to 79.16.63.25479.16.63.25516,382
6679.16.64.0/1879.16.64.1 to 79.16.127.25479.16.127.25516,382
6779.16.128.0/1879.16.128.1 to 79.16.191.25479.16.191.25516,382
6879.16.192.0/1879.16.192.1 to 79.16.255.25479.16.255.25516,382
6979.17.0.0/1879.17.0.1 to 79.17.63.25479.17.63.25516,382
7079.17.64.0/1879.17.64.1 to 79.17.127.25479.17.127.25516,382
7179.17.128.0/1879.17.128.1 to 79.17.191.25479.17.191.25516,382
7279.17.192.0/1879.17.192.1 to 79.17.255.25479.17.255.25516,382
7379.18.0.0/1879.18.0.1 to 79.18.63.25479.18.63.25516,382
7479.18.64.0/1879.18.64.1 to 79.18.127.25479.18.127.25516,382
7579.18.128.0/1879.18.128.1 to 79.18.191.25479.18.191.25516,382
7679.18.192.0/1879.18.192.1 to 79.18.255.25479.18.255.25516,382
7779.19.0.0/1879.19.0.1 to 79.19.63.25479.19.63.25516,382
7879.19.64.0/1879.19.64.1 to 79.19.127.25479.19.127.25516,382
7979.19.128.0/1879.19.128.1 to 79.19.191.25479.19.191.25516,382
8079.19.192.0/1879.19.192.1 to 79.19.255.25479.19.255.25516,382
8179.20.0.0/1879.20.0.1 to 79.20.63.25479.20.63.25516,382
8279.20.64.0/1879.20.64.1 to 79.20.127.25479.20.127.25516,382
8379.20.128.0/1879.20.128.1 to 79.20.191.25479.20.191.25516,382
8479.20.192.0/1879.20.192.1 to 79.20.255.25479.20.255.25516,382
8579.21.0.0/1879.21.0.1 to 79.21.63.25479.21.63.25516,382
8679.21.64.0/1879.21.64.1 to 79.21.127.25479.21.127.25516,382
8779.21.128.0/1879.21.128.1 to 79.21.191.25479.21.191.25516,382
8879.21.192.0/1879.21.192.1 to 79.21.255.25479.21.255.25516,382
8979.22.0.0/1879.22.0.1 to 79.22.63.25479.22.63.25516,382
9079.22.64.0/1879.22.64.1 to 79.22.127.25479.22.127.25516,382
9179.22.128.0/1879.22.128.1 to 79.22.191.25479.22.191.25516,382
9279.22.192.0/1879.22.192.1 to 79.22.255.25479.22.255.25516,382
9379.23.0.0/1879.23.0.1 to 79.23.63.25479.23.63.25516,382
9479.23.64.0/1879.23.64.1 to 79.23.127.25479.23.127.25516,382
9579.23.128.0/1879.23.128.1 to 79.23.191.25479.23.191.25516,382
9679.23.192.0/1879.23.192.1 to 79.23.255.25479.23.255.25516,382
9779.24.0.0/1879.24.0.1 to 79.24.63.25479.24.63.25516,382
9879.24.64.0/1879.24.64.1 to 79.24.127.25479.24.127.25516,382
9979.24.128.0/1879.24.128.1 to 79.24.191.25479.24.191.25516,382
10079.24.192.0/1879.24.192.1 to 79.24.255.25479.24.255.25516,382
10179.25.0.0/1879.25.0.1 to 79.25.63.25479.25.63.25516,382
10279.25.64.0/1879.25.64.1 to 79.25.127.25479.25.127.25516,382
10379.25.128.0/1879.25.128.1 to 79.25.191.25479.25.191.25516,382
10479.25.192.0/1879.25.192.1 to 79.25.255.25479.25.255.25516,382
10579.26.0.0/1879.26.0.1 to 79.26.63.25479.26.63.25516,382
10679.26.64.0/1879.26.64.1 to 79.26.127.25479.26.127.25516,382
10779.26.128.0/1879.26.128.1 to 79.26.191.25479.26.191.25516,382
10879.26.192.0/1879.26.192.1 to 79.26.255.25479.26.255.25516,382
10979.27.0.0/1879.27.0.1 to 79.27.63.25479.27.63.25516,382
11079.27.64.0/1879.27.64.1 to 79.27.127.25479.27.127.25516,382
11179.27.128.0/1879.27.128.1 to 79.27.191.25479.27.191.25516,382
11279.27.192.0/1879.27.192.1 to 79.27.255.25479.27.255.25516,382
11379.28.0.0/1879.28.0.1 to 79.28.63.25479.28.63.25516,382
11479.28.64.0/1879.28.64.1 to 79.28.127.25479.28.127.25516,382
11579.28.128.0/1879.28.128.1 to 79.28.191.25479.28.191.25516,382
11679.28.192.0/1879.28.192.1 to 79.28.255.25479.28.255.25516,382
11779.29.0.0/1879.29.0.1 to 79.29.63.25479.29.63.25516,382
11879.29.64.0/1879.29.64.1 to 79.29.127.25479.29.127.25516,382
11979.29.128.0/1879.29.128.1 to 79.29.191.25479.29.191.25516,382
12079.29.192.0/1879.29.192.1 to 79.29.255.25479.29.255.25516,382
12179.30.0.0/1879.30.0.1 to 79.30.63.25479.30.63.25516,382
12279.30.64.0/1879.30.64.1 to 79.30.127.25479.30.127.25516,382
12379.30.128.0/1879.30.128.1 to 79.30.191.25479.30.191.25516,382
12479.30.192.0/1879.30.192.1 to 79.30.255.25479.30.255.25516,382
12579.31.0.0/1879.31.0.1 to 79.31.63.25479.31.63.25516,382
12679.31.64.0/1879.31.64.1 to 79.31.127.25479.31.127.25516,382
12779.31.128.0/1879.31.128.1 to 79.31.191.25479.31.191.25516,382
12879.31.192.0/1879.31.192.1 to 79.31.255.25479.31.255.25516,382
12979.32.0.0/1879.32.0.1 to 79.32.63.25479.32.63.25516,382
13079.32.64.0/1879.32.64.1 to 79.32.127.25479.32.127.25516,382
13179.32.128.0/1879.32.128.1 to 79.32.191.25479.32.191.25516,382
13279.32.192.0/1879.32.192.1 to 79.32.255.25479.32.255.25516,382
13379.33.0.0/1879.33.0.1 to 79.33.63.25479.33.63.25516,382
13479.33.64.0/1879.33.64.1 to 79.33.127.25479.33.127.25516,382
13579.33.128.0/1879.33.128.1 to 79.33.191.25479.33.191.25516,382
13679.33.192.0/1879.33.192.1 to 79.33.255.25479.33.255.25516,382
13779.34.0.0/1879.34.0.1 to 79.34.63.25479.34.63.25516,382
13879.34.64.0/1879.34.64.1 to 79.34.127.25479.34.127.25516,382
13979.34.128.0/1879.34.128.1 to 79.34.191.25479.34.191.25516,382
14079.34.192.0/1879.34.192.1 to 79.34.255.25479.34.255.25516,382
14179.35.0.0/1879.35.0.1 to 79.35.63.25479.35.63.25516,382
14279.35.64.0/1879.35.64.1 to 79.35.127.25479.35.127.25516,382
14379.35.128.0/1879.35.128.1 to 79.35.191.25479.35.191.25516,382
14479.35.192.0/1879.35.192.1 to 79.35.255.25479.35.255.25516,382
14579.36.0.0/1879.36.0.1 to 79.36.63.25479.36.63.25516,382
14679.36.64.0/1879.36.64.1 to 79.36.127.25479.36.127.25516,382
14779.36.128.0/1879.36.128.1 to 79.36.191.25479.36.191.25516,382
14879.36.192.0/1879.36.192.1 to 79.36.255.25479.36.255.25516,382
14979.37.0.0/1879.37.0.1 to 79.37.63.25479.37.63.25516,382
15079.37.64.0/1879.37.64.1 to 79.37.127.25479.37.127.25516,382
15179.37.128.0/1879.37.128.1 to 79.37.191.25479.37.191.25516,382
15279.37.192.0/1879.37.192.1 to 79.37.255.25479.37.255.25516,382
15379.38.0.0/1879.38.0.1 to 79.38.63.25479.38.63.25516,382
15479.38.64.0/1879.38.64.1 to 79.38.127.25479.38.127.25516,382
15579.38.128.0/1879.38.128.1 to 79.38.191.25479.38.191.25516,382
15679.38.192.0/1879.38.192.1 to 79.38.255.25479.38.255.25516,382
15779.39.0.0/1879.39.0.1 to 79.39.63.25479.39.63.25516,382
15879.39.64.0/1879.39.64.1 to 79.39.127.25479.39.127.25516,382
15979.39.128.0/1879.39.128.1 to 79.39.191.25479.39.191.25516,382
16079.39.192.0/1879.39.192.1 to 79.39.255.25479.39.255.25516,382
16179.40.0.0/1879.40.0.1 to 79.40.63.25479.40.63.25516,382
16279.40.64.0/1879.40.64.1 to 79.40.127.25479.40.127.25516,382
16379.40.128.0/1879.40.128.1 to 79.40.191.25479.40.191.25516,382
16479.40.192.0/1879.40.192.1 to 79.40.255.25479.40.255.25516,382
16579.41.0.0/1879.41.0.1 to 79.41.63.25479.41.63.25516,382
16679.41.64.0/1879.41.64.1 to 79.41.127.25479.41.127.25516,382
16779.41.128.0/1879.41.128.1 to 79.41.191.25479.41.191.25516,382
16879.41.192.0/1879.41.192.1 to 79.41.255.25479.41.255.25516,382
16979.42.0.0/1879.42.0.1 to 79.42.63.25479.42.63.25516,382
17079.42.64.0/1879.42.64.1 to 79.42.127.25479.42.127.25516,382
17179.42.128.0/1879.42.128.1 to 79.42.191.25479.42.191.25516,382
17279.42.192.0/1879.42.192.1 to 79.42.255.25479.42.255.25516,382
17379.43.0.0/1879.43.0.1 to 79.43.63.25479.43.63.25516,382
17479.43.64.0/1879.43.64.1 to 79.43.127.25479.43.127.25516,382
17579.43.128.0/1879.43.128.1 to 79.43.191.25479.43.191.25516,382
17679.43.192.0/1879.43.192.1 to 79.43.255.25479.43.255.25516,382
17779.44.0.0/1879.44.0.1 to 79.44.63.25479.44.63.25516,382
17879.44.64.0/1879.44.64.1 to 79.44.127.25479.44.127.25516,382
17979.44.128.0/1879.44.128.1 to 79.44.191.25479.44.191.25516,382
18079.44.192.0/1879.44.192.1 to 79.44.255.25479.44.255.25516,382
18179.45.0.0/1879.45.0.1 to 79.45.63.25479.45.63.25516,382
18279.45.64.0/1879.45.64.1 to 79.45.127.25479.45.127.25516,382
18379.45.128.0/1879.45.128.1 to 79.45.191.25479.45.191.25516,382
18479.45.192.0/1879.45.192.1 to 79.45.255.25479.45.255.25516,382
18579.46.0.0/1879.46.0.1 to 79.46.63.25479.46.63.25516,382
18679.46.64.0/1879.46.64.1 to 79.46.127.25479.46.127.25516,382
18779.46.128.0/1879.46.128.1 to 79.46.191.25479.46.191.25516,382
18879.46.192.0/1879.46.192.1 to 79.46.255.25479.46.255.25516,382
18979.47.0.0/1879.47.0.1 to 79.47.63.25479.47.63.25516,382
19079.47.64.0/1879.47.64.1 to 79.47.127.25479.47.127.25516,382
19179.47.128.0/1879.47.128.1 to 79.47.191.25479.47.191.25516,382
19279.47.192.0/1879.47.192.1 to 79.47.255.25479.47.255.25516,382
19379.48.0.0/1879.48.0.1 to 79.48.63.25479.48.63.25516,382
19479.48.64.0/1879.48.64.1 to 79.48.127.25479.48.127.25516,382
19579.48.128.0/1879.48.128.1 to 79.48.191.25479.48.191.25516,382
19679.48.192.0/1879.48.192.1 to 79.48.255.25479.48.255.25516,382
19779.49.0.0/1879.49.0.1 to 79.49.63.25479.49.63.25516,382
19879.49.64.0/1879.49.64.1 to 79.49.127.25479.49.127.25516,382
19979.49.128.0/1879.49.128.1 to 79.49.191.25479.49.191.25516,382
20079.49.192.0/1879.49.192.1 to 79.49.255.25479.49.255.25516,382
20179.50.0.0/1879.50.0.1 to 79.50.63.25479.50.63.25516,382
20279.50.64.0/1879.50.64.1 to 79.50.127.25479.50.127.25516,382
20379.50.128.0/1879.50.128.1 to 79.50.191.25479.50.191.25516,382
20479.50.192.0/1879.50.192.1 to 79.50.255.25479.50.255.25516,382
20579.51.0.0/1879.51.0.1 to 79.51.63.25479.51.63.25516,382
20679.51.64.0/1879.51.64.1 to 79.51.127.25479.51.127.25516,382
20779.51.128.0/1879.51.128.1 to 79.51.191.25479.51.191.25516,382
20879.51.192.0/1879.51.192.1 to 79.51.255.25479.51.255.25516,382
20979.52.0.0/1879.52.0.1 to 79.52.63.25479.52.63.25516,382
21079.52.64.0/1879.52.64.1 to 79.52.127.25479.52.127.25516,382
21179.52.128.0/1879.52.128.1 to 79.52.191.25479.52.191.25516,382
21279.52.192.0/1879.52.192.1 to 79.52.255.25479.52.255.25516,382
21379.53.0.0/1879.53.0.1 to 79.53.63.25479.53.63.25516,382
21479.53.64.0/1879.53.64.1 to 79.53.127.25479.53.127.25516,382
21579.53.128.0/1879.53.128.1 to 79.53.191.25479.53.191.25516,382
21679.53.192.0/1879.53.192.1 to 79.53.255.25479.53.255.25516,382
21779.54.0.0/1879.54.0.1 to 79.54.63.25479.54.63.25516,382
21879.54.64.0/1879.54.64.1 to 79.54.127.25479.54.127.25516,382
21979.54.128.0/1879.54.128.1 to 79.54.191.25479.54.191.25516,382
22079.54.192.0/1879.54.192.1 to 79.54.255.25479.54.255.25516,382
22179.55.0.0/1879.55.0.1 to 79.55.63.25479.55.63.25516,382
22279.55.64.0/1879.55.64.1 to 79.55.127.25479.55.127.25516,382
22379.55.128.0/1879.55.128.1 to 79.55.191.25479.55.191.25516,382
22479.55.192.0/1879.55.192.1 to 79.55.255.25479.55.255.25516,382
22579.56.0.0/1879.56.0.1 to 79.56.63.25479.56.63.25516,382
22679.56.64.0/1879.56.64.1 to 79.56.127.25479.56.127.25516,382
22779.56.128.0/1879.56.128.1 to 79.56.191.25479.56.191.25516,382
22879.56.192.0/1879.56.192.1 to 79.56.255.25479.56.255.25516,382
22979.57.0.0/1879.57.0.1 to 79.57.63.25479.57.63.25516,382
23079.57.64.0/1879.57.64.1 to 79.57.127.25479.57.127.25516,382
23179.57.128.0/1879.57.128.1 to 79.57.191.25479.57.191.25516,382
23279.57.192.0/1879.57.192.1 to 79.57.255.25479.57.255.25516,382
23379.58.0.0/1879.58.0.1 to 79.58.63.25479.58.63.25516,382
23479.58.64.0/1879.58.64.1 to 79.58.127.25479.58.127.25516,382
23579.58.128.0/1879.58.128.1 to 79.58.191.25479.58.191.25516,382
23679.58.192.0/1879.58.192.1 to 79.58.255.25479.58.255.25516,382
23779.59.0.0/1879.59.0.1 to 79.59.63.25479.59.63.25516,382
23879.59.64.0/1879.59.64.1 to 79.59.127.25479.59.127.25516,382
23979.59.128.0/1879.59.128.1 to 79.59.191.25479.59.191.25516,382
24079.59.192.0/1879.59.192.1 to 79.59.255.25479.59.255.25516,382
24179.60.0.0/1879.60.0.1 to 79.60.63.25479.60.63.25516,382
24279.60.64.0/1879.60.64.1 to 79.60.127.25479.60.127.25516,382
24379.60.128.0/1879.60.128.1 to 79.60.191.25479.60.191.25516,382
24479.60.192.0/1879.60.192.1 to 79.60.255.25479.60.255.25516,382
24579.61.0.0/1879.61.0.1 to 79.61.63.25479.61.63.25516,382
24679.61.64.0/1879.61.64.1 to 79.61.127.25479.61.127.25516,382
24779.61.128.0/1879.61.128.1 to 79.61.191.25479.61.191.25516,382
24879.61.192.0/1879.61.192.1 to 79.61.255.25479.61.255.25516,382
24979.62.0.0/1879.62.0.1 to 79.62.63.25479.62.63.25516,382
25079.62.64.0/1879.62.64.1 to 79.62.127.25479.62.127.25516,382
25179.62.128.0/1879.62.128.1 to 79.62.191.25479.62.191.25516,382
25279.62.192.0/1879.62.192.1 to 79.62.255.25479.62.255.25516,382
25379.63.0.0/1879.63.0.1 to 79.63.63.25479.63.63.25516,382
25479.63.64.0/1879.63.64.1 to 79.63.127.25479.63.127.25516,382
25579.63.128.0/1879.63.128.1 to 79.63.191.25479.63.191.25516,382
25679.63.192.0/1879.63.192.1 to 79.63.255.25479.63.255.25516,382

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.