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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.

Network79.167.0.0/17
Usable hosts32,766
Subnet mask255.255.128.0
Addresses32,768
Network address
79.167.0.0
Broadcast address
79.167.127.255
First usable
79.167.0.1
Last usable
79.167.127.254
Usable hosts
32,766 (32,768 less the network and broadcast addresses)
Subnet mask
255.255.128.0
Wildcard mask
0.0.127.255 (Cisco ACLs, OSPF)
Prefix length
/17
Type
Public public
Old class
A (default /8)
As numbers
Hex 4FA70000 · Integer 1336344576 to 1336377343
Reverse DNS zones
0.167.79.in-addr.arpa
1.167.79.in-addr.arpa
2.167.79.in-addr.arpa
3.167.79.in-addr.arpa
4.167.79.in-addr.arpa
5.167.79.in-addr.arpa
6.167.79.in-addr.arpa
7.167.79.in-addr.arpa
8.167.79.in-addr.arpa
9.167.79.in-addr.arpa
10.167.79.in-addr.arpa
11.167.79.in-addr.arpa
12.167.79.in-addr.arpa
13.167.79.in-addr.arpa
14.167.79.in-addr.arpa
15.167.79.in-addr.arpa
and 112 more
/17 is not on a 8-bit boundary, so it takes 128 /24 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01001111.10100111.00000000.0000000079.167.0.0
Subnet mask11111111.11111111.10000000.00000000255.255.128.0
Network01001111.10100111.00000000.0000000079.167.0.0
Broadcast01001111.10100111.01111111.1111111179.167.127.255
Split into smaller subnets/28
/18 (2)/19 (4)/20 (8)/21 (16)/22 (32)/23 (64)/24 (128)/25 (256)/26 (512)/27 (1,024)/28 (2,048)/29 (4,096)

79.167.0.0/17 makes 2,048 subnets of /28; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
179.167.0.0/2879.167.0.1 to 79.167.0.1479.167.0.1514
279.167.0.16/2879.167.0.17 to 79.167.0.3079.167.0.3114
379.167.0.32/2879.167.0.33 to 79.167.0.4679.167.0.4714
479.167.0.48/2879.167.0.49 to 79.167.0.6279.167.0.6314
579.167.0.64/2879.167.0.65 to 79.167.0.7879.167.0.7914
679.167.0.80/2879.167.0.81 to 79.167.0.9479.167.0.9514
779.167.0.96/2879.167.0.97 to 79.167.0.11079.167.0.11114
879.167.0.112/2879.167.0.113 to 79.167.0.12679.167.0.12714
979.167.0.128/2879.167.0.129 to 79.167.0.14279.167.0.14314
1079.167.0.144/2879.167.0.145 to 79.167.0.15879.167.0.15914
1179.167.0.160/2879.167.0.161 to 79.167.0.17479.167.0.17514
1279.167.0.176/2879.167.0.177 to 79.167.0.19079.167.0.19114
1379.167.0.192/2879.167.0.193 to 79.167.0.20679.167.0.20714
1479.167.0.208/2879.167.0.209 to 79.167.0.22279.167.0.22314
1579.167.0.224/2879.167.0.225 to 79.167.0.23879.167.0.23914
1679.167.0.240/2879.167.0.241 to 79.167.0.25479.167.0.25514
1779.167.1.0/2879.167.1.1 to 79.167.1.1479.167.1.1514
1879.167.1.16/2879.167.1.17 to 79.167.1.3079.167.1.3114
1979.167.1.32/2879.167.1.33 to 79.167.1.4679.167.1.4714
2079.167.1.48/2879.167.1.49 to 79.167.1.6279.167.1.6314
2179.167.1.64/2879.167.1.65 to 79.167.1.7879.167.1.7914
2279.167.1.80/2879.167.1.81 to 79.167.1.9479.167.1.9514
2379.167.1.96/2879.167.1.97 to 79.167.1.11079.167.1.11114
2479.167.1.112/2879.167.1.113 to 79.167.1.12679.167.1.12714
2579.167.1.128/2879.167.1.129 to 79.167.1.14279.167.1.14314
2679.167.1.144/2879.167.1.145 to 79.167.1.15879.167.1.15914
2779.167.1.160/2879.167.1.161 to 79.167.1.17479.167.1.17514
2879.167.1.176/2879.167.1.177 to 79.167.1.19079.167.1.19114
2979.167.1.192/2879.167.1.193 to 79.167.1.20679.167.1.20714
3079.167.1.208/2879.167.1.209 to 79.167.1.22279.167.1.22314
3179.167.1.224/2879.167.1.225 to 79.167.1.23879.167.1.23914
3279.167.1.240/2879.167.1.241 to 79.167.1.25479.167.1.25514
3379.167.2.0/2879.167.2.1 to 79.167.2.1479.167.2.1514
3479.167.2.16/2879.167.2.17 to 79.167.2.3079.167.2.3114
3579.167.2.32/2879.167.2.33 to 79.167.2.4679.167.2.4714
3679.167.2.48/2879.167.2.49 to 79.167.2.6279.167.2.6314
3779.167.2.64/2879.167.2.65 to 79.167.2.7879.167.2.7914
3879.167.2.80/2879.167.2.81 to 79.167.2.9479.167.2.9514
3979.167.2.96/2879.167.2.97 to 79.167.2.11079.167.2.11114
4079.167.2.112/2879.167.2.113 to 79.167.2.12679.167.2.12714
4179.167.2.128/2879.167.2.129 to 79.167.2.14279.167.2.14314
4279.167.2.144/2879.167.2.145 to 79.167.2.15879.167.2.15914
4379.167.2.160/2879.167.2.161 to 79.167.2.17479.167.2.17514
4479.167.2.176/2879.167.2.177 to 79.167.2.19079.167.2.19114
4579.167.2.192/2879.167.2.193 to 79.167.2.20679.167.2.20714
4679.167.2.208/2879.167.2.209 to 79.167.2.22279.167.2.22314
4779.167.2.224/2879.167.2.225 to 79.167.2.23879.167.2.23914
4879.167.2.240/2879.167.2.241 to 79.167.2.25479.167.2.25514
4979.167.3.0/2879.167.3.1 to 79.167.3.1479.167.3.1514
5079.167.3.16/2879.167.3.17 to 79.167.3.3079.167.3.3114
5179.167.3.32/2879.167.3.33 to 79.167.3.4679.167.3.4714
5279.167.3.48/2879.167.3.49 to 79.167.3.6279.167.3.6314
5379.167.3.64/2879.167.3.65 to 79.167.3.7879.167.3.7914
5479.167.3.80/2879.167.3.81 to 79.167.3.9479.167.3.9514
5579.167.3.96/2879.167.3.97 to 79.167.3.11079.167.3.11114
5679.167.3.112/2879.167.3.113 to 79.167.3.12679.167.3.12714
5779.167.3.128/2879.167.3.129 to 79.167.3.14279.167.3.14314
5879.167.3.144/2879.167.3.145 to 79.167.3.15879.167.3.15914
5979.167.3.160/2879.167.3.161 to 79.167.3.17479.167.3.17514
6079.167.3.176/2879.167.3.177 to 79.167.3.19079.167.3.19114
6179.167.3.192/2879.167.3.193 to 79.167.3.20679.167.3.20714
6279.167.3.208/2879.167.3.209 to 79.167.3.22279.167.3.22314
6379.167.3.224/2879.167.3.225 to 79.167.3.23879.167.3.23914
6479.167.3.240/2879.167.3.241 to 79.167.3.25479.167.3.25514
6579.167.4.0/2879.167.4.1 to 79.167.4.1479.167.4.1514
6679.167.4.16/2879.167.4.17 to 79.167.4.3079.167.4.3114
6779.167.4.32/2879.167.4.33 to 79.167.4.4679.167.4.4714
6879.167.4.48/2879.167.4.49 to 79.167.4.6279.167.4.6314
6979.167.4.64/2879.167.4.65 to 79.167.4.7879.167.4.7914
7079.167.4.80/2879.167.4.81 to 79.167.4.9479.167.4.9514
7179.167.4.96/2879.167.4.97 to 79.167.4.11079.167.4.11114
7279.167.4.112/2879.167.4.113 to 79.167.4.12679.167.4.12714
7379.167.4.128/2879.167.4.129 to 79.167.4.14279.167.4.14314
7479.167.4.144/2879.167.4.145 to 79.167.4.15879.167.4.15914
7579.167.4.160/2879.167.4.161 to 79.167.4.17479.167.4.17514
7679.167.4.176/2879.167.4.177 to 79.167.4.19079.167.4.19114
7779.167.4.192/2879.167.4.193 to 79.167.4.20679.167.4.20714
7879.167.4.208/2879.167.4.209 to 79.167.4.22279.167.4.22314
7979.167.4.224/2879.167.4.225 to 79.167.4.23879.167.4.23914
8079.167.4.240/2879.167.4.241 to 79.167.4.25479.167.4.25514
8179.167.5.0/2879.167.5.1 to 79.167.5.1479.167.5.1514
8279.167.5.16/2879.167.5.17 to 79.167.5.3079.167.5.3114
8379.167.5.32/2879.167.5.33 to 79.167.5.4679.167.5.4714
8479.167.5.48/2879.167.5.49 to 79.167.5.6279.167.5.6314
8579.167.5.64/2879.167.5.65 to 79.167.5.7879.167.5.7914
8679.167.5.80/2879.167.5.81 to 79.167.5.9479.167.5.9514
8779.167.5.96/2879.167.5.97 to 79.167.5.11079.167.5.11114
8879.167.5.112/2879.167.5.113 to 79.167.5.12679.167.5.12714
8979.167.5.128/2879.167.5.129 to 79.167.5.14279.167.5.14314
9079.167.5.144/2879.167.5.145 to 79.167.5.15879.167.5.15914
9179.167.5.160/2879.167.5.161 to 79.167.5.17479.167.5.17514
9279.167.5.176/2879.167.5.177 to 79.167.5.19079.167.5.19114
9379.167.5.192/2879.167.5.193 to 79.167.5.20679.167.5.20714
9479.167.5.208/2879.167.5.209 to 79.167.5.22279.167.5.22314
9579.167.5.224/2879.167.5.225 to 79.167.5.23879.167.5.23914
9679.167.5.240/2879.167.5.241 to 79.167.5.25479.167.5.25514
9779.167.6.0/2879.167.6.1 to 79.167.6.1479.167.6.1514
9879.167.6.16/2879.167.6.17 to 79.167.6.3079.167.6.3114
9979.167.6.32/2879.167.6.33 to 79.167.6.4679.167.6.4714
10079.167.6.48/2879.167.6.49 to 79.167.6.6279.167.6.6314
10179.167.6.64/2879.167.6.65 to 79.167.6.7879.167.6.7914
10279.167.6.80/2879.167.6.81 to 79.167.6.9479.167.6.9514
10379.167.6.96/2879.167.6.97 to 79.167.6.11079.167.6.11114
10479.167.6.112/2879.167.6.113 to 79.167.6.12679.167.6.12714
10579.167.6.128/2879.167.6.129 to 79.167.6.14279.167.6.14314
10679.167.6.144/2879.167.6.145 to 79.167.6.15879.167.6.15914
10779.167.6.160/2879.167.6.161 to 79.167.6.17479.167.6.17514
10879.167.6.176/2879.167.6.177 to 79.167.6.19079.167.6.19114
10979.167.6.192/2879.167.6.193 to 79.167.6.20679.167.6.20714
11079.167.6.208/2879.167.6.209 to 79.167.6.22279.167.6.22314
11179.167.6.224/2879.167.6.225 to 79.167.6.23879.167.6.23914
11279.167.6.240/2879.167.6.241 to 79.167.6.25479.167.6.25514
11379.167.7.0/2879.167.7.1 to 79.167.7.1479.167.7.1514
11479.167.7.16/2879.167.7.17 to 79.167.7.3079.167.7.3114
11579.167.7.32/2879.167.7.33 to 79.167.7.4679.167.7.4714
11679.167.7.48/2879.167.7.49 to 79.167.7.6279.167.7.6314
11779.167.7.64/2879.167.7.65 to 79.167.7.7879.167.7.7914
11879.167.7.80/2879.167.7.81 to 79.167.7.9479.167.7.9514
11979.167.7.96/2879.167.7.97 to 79.167.7.11079.167.7.11114
12079.167.7.112/2879.167.7.113 to 79.167.7.12679.167.7.12714
12179.167.7.128/2879.167.7.129 to 79.167.7.14279.167.7.14314
12279.167.7.144/2879.167.7.145 to 79.167.7.15879.167.7.15914
12379.167.7.160/2879.167.7.161 to 79.167.7.17479.167.7.17514
12479.167.7.176/2879.167.7.177 to 79.167.7.19079.167.7.19114
12579.167.7.192/2879.167.7.193 to 79.167.7.20679.167.7.20714
12679.167.7.208/2879.167.7.209 to 79.167.7.22279.167.7.22314
12779.167.7.224/2879.167.7.225 to 79.167.7.23879.167.7.23914
12879.167.7.240/2879.167.7.241 to 79.167.7.25479.167.7.25514
12979.167.8.0/2879.167.8.1 to 79.167.8.1479.167.8.1514
13079.167.8.16/2879.167.8.17 to 79.167.8.3079.167.8.3114
13179.167.8.32/2879.167.8.33 to 79.167.8.4679.167.8.4714
13279.167.8.48/2879.167.8.49 to 79.167.8.6279.167.8.6314
13379.167.8.64/2879.167.8.65 to 79.167.8.7879.167.8.7914
13479.167.8.80/2879.167.8.81 to 79.167.8.9479.167.8.9514
13579.167.8.96/2879.167.8.97 to 79.167.8.11079.167.8.11114
13679.167.8.112/2879.167.8.113 to 79.167.8.12679.167.8.12714
13779.167.8.128/2879.167.8.129 to 79.167.8.14279.167.8.14314
13879.167.8.144/2879.167.8.145 to 79.167.8.15879.167.8.15914
13979.167.8.160/2879.167.8.161 to 79.167.8.17479.167.8.17514
14079.167.8.176/2879.167.8.177 to 79.167.8.19079.167.8.19114
14179.167.8.192/2879.167.8.193 to 79.167.8.20679.167.8.20714
14279.167.8.208/2879.167.8.209 to 79.167.8.22279.167.8.22314
14379.167.8.224/2879.167.8.225 to 79.167.8.23879.167.8.23914
14479.167.8.240/2879.167.8.241 to 79.167.8.25479.167.8.25514
14579.167.9.0/2879.167.9.1 to 79.167.9.1479.167.9.1514
14679.167.9.16/2879.167.9.17 to 79.167.9.3079.167.9.3114
14779.167.9.32/2879.167.9.33 to 79.167.9.4679.167.9.4714
14879.167.9.48/2879.167.9.49 to 79.167.9.6279.167.9.6314
14979.167.9.64/2879.167.9.65 to 79.167.9.7879.167.9.7914
15079.167.9.80/2879.167.9.81 to 79.167.9.9479.167.9.9514
15179.167.9.96/2879.167.9.97 to 79.167.9.11079.167.9.11114
15279.167.9.112/2879.167.9.113 to 79.167.9.12679.167.9.12714
15379.167.9.128/2879.167.9.129 to 79.167.9.14279.167.9.14314
15479.167.9.144/2879.167.9.145 to 79.167.9.15879.167.9.15914
15579.167.9.160/2879.167.9.161 to 79.167.9.17479.167.9.17514
15679.167.9.176/2879.167.9.177 to 79.167.9.19079.167.9.19114
15779.167.9.192/2879.167.9.193 to 79.167.9.20679.167.9.20714
15879.167.9.208/2879.167.9.209 to 79.167.9.22279.167.9.22314
15979.167.9.224/2879.167.9.225 to 79.167.9.23879.167.9.23914
16079.167.9.240/2879.167.9.241 to 79.167.9.25479.167.9.25514
16179.167.10.0/2879.167.10.1 to 79.167.10.1479.167.10.1514
16279.167.10.16/2879.167.10.17 to 79.167.10.3079.167.10.3114
16379.167.10.32/2879.167.10.33 to 79.167.10.4679.167.10.4714
16479.167.10.48/2879.167.10.49 to 79.167.10.6279.167.10.6314
16579.167.10.64/2879.167.10.65 to 79.167.10.7879.167.10.7914
16679.167.10.80/2879.167.10.81 to 79.167.10.9479.167.10.9514
16779.167.10.96/2879.167.10.97 to 79.167.10.11079.167.10.11114
16879.167.10.112/2879.167.10.113 to 79.167.10.12679.167.10.12714
16979.167.10.128/2879.167.10.129 to 79.167.10.14279.167.10.14314
17079.167.10.144/2879.167.10.145 to 79.167.10.15879.167.10.15914
17179.167.10.160/2879.167.10.161 to 79.167.10.17479.167.10.17514
17279.167.10.176/2879.167.10.177 to 79.167.10.19079.167.10.19114
17379.167.10.192/2879.167.10.193 to 79.167.10.20679.167.10.20714
17479.167.10.208/2879.167.10.209 to 79.167.10.22279.167.10.22314
17579.167.10.224/2879.167.10.225 to 79.167.10.23879.167.10.23914
17679.167.10.240/2879.167.10.241 to 79.167.10.25479.167.10.25514
17779.167.11.0/2879.167.11.1 to 79.167.11.1479.167.11.1514
17879.167.11.16/2879.167.11.17 to 79.167.11.3079.167.11.3114
17979.167.11.32/2879.167.11.33 to 79.167.11.4679.167.11.4714
18079.167.11.48/2879.167.11.49 to 79.167.11.6279.167.11.6314
18179.167.11.64/2879.167.11.65 to 79.167.11.7879.167.11.7914
18279.167.11.80/2879.167.11.81 to 79.167.11.9479.167.11.9514
18379.167.11.96/2879.167.11.97 to 79.167.11.11079.167.11.11114
18479.167.11.112/2879.167.11.113 to 79.167.11.12679.167.11.12714
18579.167.11.128/2879.167.11.129 to 79.167.11.14279.167.11.14314
18679.167.11.144/2879.167.11.145 to 79.167.11.15879.167.11.15914
18779.167.11.160/2879.167.11.161 to 79.167.11.17479.167.11.17514
18879.167.11.176/2879.167.11.177 to 79.167.11.19079.167.11.19114
18979.167.11.192/2879.167.11.193 to 79.167.11.20679.167.11.20714
19079.167.11.208/2879.167.11.209 to 79.167.11.22279.167.11.22314
19179.167.11.224/2879.167.11.225 to 79.167.11.23879.167.11.23914
19279.167.11.240/2879.167.11.241 to 79.167.11.25479.167.11.25514
19379.167.12.0/2879.167.12.1 to 79.167.12.1479.167.12.1514
19479.167.12.16/2879.167.12.17 to 79.167.12.3079.167.12.3114
19579.167.12.32/2879.167.12.33 to 79.167.12.4679.167.12.4714
19679.167.12.48/2879.167.12.49 to 79.167.12.6279.167.12.6314
19779.167.12.64/2879.167.12.65 to 79.167.12.7879.167.12.7914
19879.167.12.80/2879.167.12.81 to 79.167.12.9479.167.12.9514
19979.167.12.96/2879.167.12.97 to 79.167.12.11079.167.12.11114
20079.167.12.112/2879.167.12.113 to 79.167.12.12679.167.12.12714
20179.167.12.128/2879.167.12.129 to 79.167.12.14279.167.12.14314
20279.167.12.144/2879.167.12.145 to 79.167.12.15879.167.12.15914
20379.167.12.160/2879.167.12.161 to 79.167.12.17479.167.12.17514
20479.167.12.176/2879.167.12.177 to 79.167.12.19079.167.12.19114
20579.167.12.192/2879.167.12.193 to 79.167.12.20679.167.12.20714
20679.167.12.208/2879.167.12.209 to 79.167.12.22279.167.12.22314
20779.167.12.224/2879.167.12.225 to 79.167.12.23879.167.12.23914
20879.167.12.240/2879.167.12.241 to 79.167.12.25479.167.12.25514
20979.167.13.0/2879.167.13.1 to 79.167.13.1479.167.13.1514
21079.167.13.16/2879.167.13.17 to 79.167.13.3079.167.13.3114
21179.167.13.32/2879.167.13.33 to 79.167.13.4679.167.13.4714
21279.167.13.48/2879.167.13.49 to 79.167.13.6279.167.13.6314
21379.167.13.64/2879.167.13.65 to 79.167.13.7879.167.13.7914
21479.167.13.80/2879.167.13.81 to 79.167.13.9479.167.13.9514
21579.167.13.96/2879.167.13.97 to 79.167.13.11079.167.13.11114
21679.167.13.112/2879.167.13.113 to 79.167.13.12679.167.13.12714
21779.167.13.128/2879.167.13.129 to 79.167.13.14279.167.13.14314
21879.167.13.144/2879.167.13.145 to 79.167.13.15879.167.13.15914
21979.167.13.160/2879.167.13.161 to 79.167.13.17479.167.13.17514
22079.167.13.176/2879.167.13.177 to 79.167.13.19079.167.13.19114
22179.167.13.192/2879.167.13.193 to 79.167.13.20679.167.13.20714
22279.167.13.208/2879.167.13.209 to 79.167.13.22279.167.13.22314
22379.167.13.224/2879.167.13.225 to 79.167.13.23879.167.13.23914
22479.167.13.240/2879.167.13.241 to 79.167.13.25479.167.13.25514
22579.167.14.0/2879.167.14.1 to 79.167.14.1479.167.14.1514
22679.167.14.16/2879.167.14.17 to 79.167.14.3079.167.14.3114
22779.167.14.32/2879.167.14.33 to 79.167.14.4679.167.14.4714
22879.167.14.48/2879.167.14.49 to 79.167.14.6279.167.14.6314
22979.167.14.64/2879.167.14.65 to 79.167.14.7879.167.14.7914
23079.167.14.80/2879.167.14.81 to 79.167.14.9479.167.14.9514
23179.167.14.96/2879.167.14.97 to 79.167.14.11079.167.14.11114
23279.167.14.112/2879.167.14.113 to 79.167.14.12679.167.14.12714
23379.167.14.128/2879.167.14.129 to 79.167.14.14279.167.14.14314
23479.167.14.144/2879.167.14.145 to 79.167.14.15879.167.14.15914
23579.167.14.160/2879.167.14.161 to 79.167.14.17479.167.14.17514
23679.167.14.176/2879.167.14.177 to 79.167.14.19079.167.14.19114
23779.167.14.192/2879.167.14.193 to 79.167.14.20679.167.14.20714
23879.167.14.208/2879.167.14.209 to 79.167.14.22279.167.14.22314
23979.167.14.224/2879.167.14.225 to 79.167.14.23879.167.14.23914
24079.167.14.240/2879.167.14.241 to 79.167.14.25479.167.14.25514
24179.167.15.0/2879.167.15.1 to 79.167.15.1479.167.15.1514
24279.167.15.16/2879.167.15.17 to 79.167.15.3079.167.15.3114
24379.167.15.32/2879.167.15.33 to 79.167.15.4679.167.15.4714
24479.167.15.48/2879.167.15.49 to 79.167.15.6279.167.15.6314
24579.167.15.64/2879.167.15.65 to 79.167.15.7879.167.15.7914
24679.167.15.80/2879.167.15.81 to 79.167.15.9479.167.15.9514
24779.167.15.96/2879.167.15.97 to 79.167.15.11079.167.15.11114
24879.167.15.112/2879.167.15.113 to 79.167.15.12679.167.15.12714
24979.167.15.128/2879.167.15.129 to 79.167.15.14279.167.15.14314
25079.167.15.144/2879.167.15.145 to 79.167.15.15879.167.15.15914
25179.167.15.160/2879.167.15.161 to 79.167.15.17479.167.15.17514
25279.167.15.176/2879.167.15.177 to 79.167.15.19079.167.15.19114
25379.167.15.192/2879.167.15.193 to 79.167.15.20679.167.15.20714
25479.167.15.208/2879.167.15.209 to 79.167.15.22279.167.15.22314
25579.167.15.224/2879.167.15.225 to 79.167.15.23879.167.15.23914
25679.167.15.240/2879.167.15.241 to 79.167.15.25479.167.15.25514

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.