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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.

Network10.0.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
10.0.0.0
Broadcast address
10.63.255.255
First usable
10.0.0.1
Last usable
10.63.255.254
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
Private (RFC 1918) 10.0.0.0/8
Office and home networks; not routed on the internet
Old class
A (default /8)
As numbers
Hex 0A000000 · Integer 167772160 to 171966463
Reverse DNS zones
0.10.in-addr.arpa
1.10.in-addr.arpa
2.10.in-addr.arpa
3.10.in-addr.arpa
4.10.in-addr.arpa
5.10.in-addr.arpa
6.10.in-addr.arpa
7.10.in-addr.arpa
8.10.in-addr.arpa
9.10.in-addr.arpa
10.10.in-addr.arpa
11.10.in-addr.arpa
12.10.in-addr.arpa
13.10.in-addr.arpa
14.10.in-addr.arpa
15.10.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
Address00001010.00000000.00000000.0000000010.0.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network00001010.00000000.00000000.0000000010.0.0.0
Broadcast00001010.00111111.11111111.1111111110.63.255.255
Split into smaller subnets/20
/11 (2)/12 (4)/13 (8)/14 (16)/15 (32)/16 (64)/17 (128)/18 (256)/19 (512)/20 (1,024)/21 (2,048)/22 (4,096)

10.0.0.0/10 makes 1,024 subnets of /20; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
110.0.0.0/2010.0.0.1 to 10.0.15.25410.0.15.2554,094
210.0.16.0/2010.0.16.1 to 10.0.31.25410.0.31.2554,094
310.0.32.0/2010.0.32.1 to 10.0.47.25410.0.47.2554,094
410.0.48.0/2010.0.48.1 to 10.0.63.25410.0.63.2554,094
510.0.64.0/2010.0.64.1 to 10.0.79.25410.0.79.2554,094
610.0.80.0/2010.0.80.1 to 10.0.95.25410.0.95.2554,094
710.0.96.0/2010.0.96.1 to 10.0.111.25410.0.111.2554,094
810.0.112.0/2010.0.112.1 to 10.0.127.25410.0.127.2554,094
910.0.128.0/2010.0.128.1 to 10.0.143.25410.0.143.2554,094
1010.0.144.0/2010.0.144.1 to 10.0.159.25410.0.159.2554,094
1110.0.160.0/2010.0.160.1 to 10.0.175.25410.0.175.2554,094
1210.0.176.0/2010.0.176.1 to 10.0.191.25410.0.191.2554,094
1310.0.192.0/2010.0.192.1 to 10.0.207.25410.0.207.2554,094
1410.0.208.0/2010.0.208.1 to 10.0.223.25410.0.223.2554,094
1510.0.224.0/2010.0.224.1 to 10.0.239.25410.0.239.2554,094
1610.0.240.0/2010.0.240.1 to 10.0.255.25410.0.255.2554,094
1710.1.0.0/2010.1.0.1 to 10.1.15.25410.1.15.2554,094
1810.1.16.0/2010.1.16.1 to 10.1.31.25410.1.31.2554,094
1910.1.32.0/2010.1.32.1 to 10.1.47.25410.1.47.2554,094
2010.1.48.0/2010.1.48.1 to 10.1.63.25410.1.63.2554,094
2110.1.64.0/2010.1.64.1 to 10.1.79.25410.1.79.2554,094
2210.1.80.0/2010.1.80.1 to 10.1.95.25410.1.95.2554,094
2310.1.96.0/2010.1.96.1 to 10.1.111.25410.1.111.2554,094
2410.1.112.0/2010.1.112.1 to 10.1.127.25410.1.127.2554,094
2510.1.128.0/2010.1.128.1 to 10.1.143.25410.1.143.2554,094
2610.1.144.0/2010.1.144.1 to 10.1.159.25410.1.159.2554,094
2710.1.160.0/2010.1.160.1 to 10.1.175.25410.1.175.2554,094
2810.1.176.0/2010.1.176.1 to 10.1.191.25410.1.191.2554,094
2910.1.192.0/2010.1.192.1 to 10.1.207.25410.1.207.2554,094
3010.1.208.0/2010.1.208.1 to 10.1.223.25410.1.223.2554,094
3110.1.224.0/2010.1.224.1 to 10.1.239.25410.1.239.2554,094
3210.1.240.0/2010.1.240.1 to 10.1.255.25410.1.255.2554,094
3310.2.0.0/2010.2.0.1 to 10.2.15.25410.2.15.2554,094
3410.2.16.0/2010.2.16.1 to 10.2.31.25410.2.31.2554,094
3510.2.32.0/2010.2.32.1 to 10.2.47.25410.2.47.2554,094
3610.2.48.0/2010.2.48.1 to 10.2.63.25410.2.63.2554,094
3710.2.64.0/2010.2.64.1 to 10.2.79.25410.2.79.2554,094
3810.2.80.0/2010.2.80.1 to 10.2.95.25410.2.95.2554,094
3910.2.96.0/2010.2.96.1 to 10.2.111.25410.2.111.2554,094
4010.2.112.0/2010.2.112.1 to 10.2.127.25410.2.127.2554,094
4110.2.128.0/2010.2.128.1 to 10.2.143.25410.2.143.2554,094
4210.2.144.0/2010.2.144.1 to 10.2.159.25410.2.159.2554,094
4310.2.160.0/2010.2.160.1 to 10.2.175.25410.2.175.2554,094
4410.2.176.0/2010.2.176.1 to 10.2.191.25410.2.191.2554,094
4510.2.192.0/2010.2.192.1 to 10.2.207.25410.2.207.2554,094
4610.2.208.0/2010.2.208.1 to 10.2.223.25410.2.223.2554,094
4710.2.224.0/2010.2.224.1 to 10.2.239.25410.2.239.2554,094
4810.2.240.0/2010.2.240.1 to 10.2.255.25410.2.255.2554,094
4910.3.0.0/2010.3.0.1 to 10.3.15.25410.3.15.2554,094
5010.3.16.0/2010.3.16.1 to 10.3.31.25410.3.31.2554,094
5110.3.32.0/2010.3.32.1 to 10.3.47.25410.3.47.2554,094
5210.3.48.0/2010.3.48.1 to 10.3.63.25410.3.63.2554,094
5310.3.64.0/2010.3.64.1 to 10.3.79.25410.3.79.2554,094
5410.3.80.0/2010.3.80.1 to 10.3.95.25410.3.95.2554,094
5510.3.96.0/2010.3.96.1 to 10.3.111.25410.3.111.2554,094
5610.3.112.0/2010.3.112.1 to 10.3.127.25410.3.127.2554,094
5710.3.128.0/2010.3.128.1 to 10.3.143.25410.3.143.2554,094
5810.3.144.0/2010.3.144.1 to 10.3.159.25410.3.159.2554,094
5910.3.160.0/2010.3.160.1 to 10.3.175.25410.3.175.2554,094
6010.3.176.0/2010.3.176.1 to 10.3.191.25410.3.191.2554,094
6110.3.192.0/2010.3.192.1 to 10.3.207.25410.3.207.2554,094
6210.3.208.0/2010.3.208.1 to 10.3.223.25410.3.223.2554,094
6310.3.224.0/2010.3.224.1 to 10.3.239.25410.3.239.2554,094
6410.3.240.0/2010.3.240.1 to 10.3.255.25410.3.255.2554,094
6510.4.0.0/2010.4.0.1 to 10.4.15.25410.4.15.2554,094
6610.4.16.0/2010.4.16.1 to 10.4.31.25410.4.31.2554,094
6710.4.32.0/2010.4.32.1 to 10.4.47.25410.4.47.2554,094
6810.4.48.0/2010.4.48.1 to 10.4.63.25410.4.63.2554,094
6910.4.64.0/2010.4.64.1 to 10.4.79.25410.4.79.2554,094
7010.4.80.0/2010.4.80.1 to 10.4.95.25410.4.95.2554,094
7110.4.96.0/2010.4.96.1 to 10.4.111.25410.4.111.2554,094
7210.4.112.0/2010.4.112.1 to 10.4.127.25410.4.127.2554,094
7310.4.128.0/2010.4.128.1 to 10.4.143.25410.4.143.2554,094
7410.4.144.0/2010.4.144.1 to 10.4.159.25410.4.159.2554,094
7510.4.160.0/2010.4.160.1 to 10.4.175.25410.4.175.2554,094
7610.4.176.0/2010.4.176.1 to 10.4.191.25410.4.191.2554,094
7710.4.192.0/2010.4.192.1 to 10.4.207.25410.4.207.2554,094
7810.4.208.0/2010.4.208.1 to 10.4.223.25410.4.223.2554,094
7910.4.224.0/2010.4.224.1 to 10.4.239.25410.4.239.2554,094
8010.4.240.0/2010.4.240.1 to 10.4.255.25410.4.255.2554,094
8110.5.0.0/2010.5.0.1 to 10.5.15.25410.5.15.2554,094
8210.5.16.0/2010.5.16.1 to 10.5.31.25410.5.31.2554,094
8310.5.32.0/2010.5.32.1 to 10.5.47.25410.5.47.2554,094
8410.5.48.0/2010.5.48.1 to 10.5.63.25410.5.63.2554,094
8510.5.64.0/2010.5.64.1 to 10.5.79.25410.5.79.2554,094
8610.5.80.0/2010.5.80.1 to 10.5.95.25410.5.95.2554,094
8710.5.96.0/2010.5.96.1 to 10.5.111.25410.5.111.2554,094
8810.5.112.0/2010.5.112.1 to 10.5.127.25410.5.127.2554,094
8910.5.128.0/2010.5.128.1 to 10.5.143.25410.5.143.2554,094
9010.5.144.0/2010.5.144.1 to 10.5.159.25410.5.159.2554,094
9110.5.160.0/2010.5.160.1 to 10.5.175.25410.5.175.2554,094
9210.5.176.0/2010.5.176.1 to 10.5.191.25410.5.191.2554,094
9310.5.192.0/2010.5.192.1 to 10.5.207.25410.5.207.2554,094
9410.5.208.0/2010.5.208.1 to 10.5.223.25410.5.223.2554,094
9510.5.224.0/2010.5.224.1 to 10.5.239.25410.5.239.2554,094
9610.5.240.0/2010.5.240.1 to 10.5.255.25410.5.255.2554,094
9710.6.0.0/2010.6.0.1 to 10.6.15.25410.6.15.2554,094
9810.6.16.0/2010.6.16.1 to 10.6.31.25410.6.31.2554,094
9910.6.32.0/2010.6.32.1 to 10.6.47.25410.6.47.2554,094
10010.6.48.0/2010.6.48.1 to 10.6.63.25410.6.63.2554,094
10110.6.64.0/2010.6.64.1 to 10.6.79.25410.6.79.2554,094
10210.6.80.0/2010.6.80.1 to 10.6.95.25410.6.95.2554,094
10310.6.96.0/2010.6.96.1 to 10.6.111.25410.6.111.2554,094
10410.6.112.0/2010.6.112.1 to 10.6.127.25410.6.127.2554,094
10510.6.128.0/2010.6.128.1 to 10.6.143.25410.6.143.2554,094
10610.6.144.0/2010.6.144.1 to 10.6.159.25410.6.159.2554,094
10710.6.160.0/2010.6.160.1 to 10.6.175.25410.6.175.2554,094
10810.6.176.0/2010.6.176.1 to 10.6.191.25410.6.191.2554,094
10910.6.192.0/2010.6.192.1 to 10.6.207.25410.6.207.2554,094
11010.6.208.0/2010.6.208.1 to 10.6.223.25410.6.223.2554,094
11110.6.224.0/2010.6.224.1 to 10.6.239.25410.6.239.2554,094
11210.6.240.0/2010.6.240.1 to 10.6.255.25410.6.255.2554,094
11310.7.0.0/2010.7.0.1 to 10.7.15.25410.7.15.2554,094
11410.7.16.0/2010.7.16.1 to 10.7.31.25410.7.31.2554,094
11510.7.32.0/2010.7.32.1 to 10.7.47.25410.7.47.2554,094
11610.7.48.0/2010.7.48.1 to 10.7.63.25410.7.63.2554,094
11710.7.64.0/2010.7.64.1 to 10.7.79.25410.7.79.2554,094
11810.7.80.0/2010.7.80.1 to 10.7.95.25410.7.95.2554,094
11910.7.96.0/2010.7.96.1 to 10.7.111.25410.7.111.2554,094
12010.7.112.0/2010.7.112.1 to 10.7.127.25410.7.127.2554,094
12110.7.128.0/2010.7.128.1 to 10.7.143.25410.7.143.2554,094
12210.7.144.0/2010.7.144.1 to 10.7.159.25410.7.159.2554,094
12310.7.160.0/2010.7.160.1 to 10.7.175.25410.7.175.2554,094
12410.7.176.0/2010.7.176.1 to 10.7.191.25410.7.191.2554,094
12510.7.192.0/2010.7.192.1 to 10.7.207.25410.7.207.2554,094
12610.7.208.0/2010.7.208.1 to 10.7.223.25410.7.223.2554,094
12710.7.224.0/2010.7.224.1 to 10.7.239.25410.7.239.2554,094
12810.7.240.0/2010.7.240.1 to 10.7.255.25410.7.255.2554,094
12910.8.0.0/2010.8.0.1 to 10.8.15.25410.8.15.2554,094
13010.8.16.0/2010.8.16.1 to 10.8.31.25410.8.31.2554,094
13110.8.32.0/2010.8.32.1 to 10.8.47.25410.8.47.2554,094
13210.8.48.0/2010.8.48.1 to 10.8.63.25410.8.63.2554,094
13310.8.64.0/2010.8.64.1 to 10.8.79.25410.8.79.2554,094
13410.8.80.0/2010.8.80.1 to 10.8.95.25410.8.95.2554,094
13510.8.96.0/2010.8.96.1 to 10.8.111.25410.8.111.2554,094
13610.8.112.0/2010.8.112.1 to 10.8.127.25410.8.127.2554,094
13710.8.128.0/2010.8.128.1 to 10.8.143.25410.8.143.2554,094
13810.8.144.0/2010.8.144.1 to 10.8.159.25410.8.159.2554,094
13910.8.160.0/2010.8.160.1 to 10.8.175.25410.8.175.2554,094
14010.8.176.0/2010.8.176.1 to 10.8.191.25410.8.191.2554,094
14110.8.192.0/2010.8.192.1 to 10.8.207.25410.8.207.2554,094
14210.8.208.0/2010.8.208.1 to 10.8.223.25410.8.223.2554,094
14310.8.224.0/2010.8.224.1 to 10.8.239.25410.8.239.2554,094
14410.8.240.0/2010.8.240.1 to 10.8.255.25410.8.255.2554,094
14510.9.0.0/2010.9.0.1 to 10.9.15.25410.9.15.2554,094
14610.9.16.0/2010.9.16.1 to 10.9.31.25410.9.31.2554,094
14710.9.32.0/2010.9.32.1 to 10.9.47.25410.9.47.2554,094
14810.9.48.0/2010.9.48.1 to 10.9.63.25410.9.63.2554,094
14910.9.64.0/2010.9.64.1 to 10.9.79.25410.9.79.2554,094
15010.9.80.0/2010.9.80.1 to 10.9.95.25410.9.95.2554,094
15110.9.96.0/2010.9.96.1 to 10.9.111.25410.9.111.2554,094
15210.9.112.0/2010.9.112.1 to 10.9.127.25410.9.127.2554,094
15310.9.128.0/2010.9.128.1 to 10.9.143.25410.9.143.2554,094
15410.9.144.0/2010.9.144.1 to 10.9.159.25410.9.159.2554,094
15510.9.160.0/2010.9.160.1 to 10.9.175.25410.9.175.2554,094
15610.9.176.0/2010.9.176.1 to 10.9.191.25410.9.191.2554,094
15710.9.192.0/2010.9.192.1 to 10.9.207.25410.9.207.2554,094
15810.9.208.0/2010.9.208.1 to 10.9.223.25410.9.223.2554,094
15910.9.224.0/2010.9.224.1 to 10.9.239.25410.9.239.2554,094
16010.9.240.0/2010.9.240.1 to 10.9.255.25410.9.255.2554,094
16110.10.0.0/2010.10.0.1 to 10.10.15.25410.10.15.2554,094
16210.10.16.0/2010.10.16.1 to 10.10.31.25410.10.31.2554,094
16310.10.32.0/2010.10.32.1 to 10.10.47.25410.10.47.2554,094
16410.10.48.0/2010.10.48.1 to 10.10.63.25410.10.63.2554,094
16510.10.64.0/2010.10.64.1 to 10.10.79.25410.10.79.2554,094
16610.10.80.0/2010.10.80.1 to 10.10.95.25410.10.95.2554,094
16710.10.96.0/2010.10.96.1 to 10.10.111.25410.10.111.2554,094
16810.10.112.0/2010.10.112.1 to 10.10.127.25410.10.127.2554,094
16910.10.128.0/2010.10.128.1 to 10.10.143.25410.10.143.2554,094
17010.10.144.0/2010.10.144.1 to 10.10.159.25410.10.159.2554,094
17110.10.160.0/2010.10.160.1 to 10.10.175.25410.10.175.2554,094
17210.10.176.0/2010.10.176.1 to 10.10.191.25410.10.191.2554,094
17310.10.192.0/2010.10.192.1 to 10.10.207.25410.10.207.2554,094
17410.10.208.0/2010.10.208.1 to 10.10.223.25410.10.223.2554,094
17510.10.224.0/2010.10.224.1 to 10.10.239.25410.10.239.2554,094
17610.10.240.0/2010.10.240.1 to 10.10.255.25410.10.255.2554,094
17710.11.0.0/2010.11.0.1 to 10.11.15.25410.11.15.2554,094
17810.11.16.0/2010.11.16.1 to 10.11.31.25410.11.31.2554,094
17910.11.32.0/2010.11.32.1 to 10.11.47.25410.11.47.2554,094
18010.11.48.0/2010.11.48.1 to 10.11.63.25410.11.63.2554,094
18110.11.64.0/2010.11.64.1 to 10.11.79.25410.11.79.2554,094
18210.11.80.0/2010.11.80.1 to 10.11.95.25410.11.95.2554,094
18310.11.96.0/2010.11.96.1 to 10.11.111.25410.11.111.2554,094
18410.11.112.0/2010.11.112.1 to 10.11.127.25410.11.127.2554,094
18510.11.128.0/2010.11.128.1 to 10.11.143.25410.11.143.2554,094
18610.11.144.0/2010.11.144.1 to 10.11.159.25410.11.159.2554,094
18710.11.160.0/2010.11.160.1 to 10.11.175.25410.11.175.2554,094
18810.11.176.0/2010.11.176.1 to 10.11.191.25410.11.191.2554,094
18910.11.192.0/2010.11.192.1 to 10.11.207.25410.11.207.2554,094
19010.11.208.0/2010.11.208.1 to 10.11.223.25410.11.223.2554,094
19110.11.224.0/2010.11.224.1 to 10.11.239.25410.11.239.2554,094
19210.11.240.0/2010.11.240.1 to 10.11.255.25410.11.255.2554,094
19310.12.0.0/2010.12.0.1 to 10.12.15.25410.12.15.2554,094
19410.12.16.0/2010.12.16.1 to 10.12.31.25410.12.31.2554,094
19510.12.32.0/2010.12.32.1 to 10.12.47.25410.12.47.2554,094
19610.12.48.0/2010.12.48.1 to 10.12.63.25410.12.63.2554,094
19710.12.64.0/2010.12.64.1 to 10.12.79.25410.12.79.2554,094
19810.12.80.0/2010.12.80.1 to 10.12.95.25410.12.95.2554,094
19910.12.96.0/2010.12.96.1 to 10.12.111.25410.12.111.2554,094
20010.12.112.0/2010.12.112.1 to 10.12.127.25410.12.127.2554,094
20110.12.128.0/2010.12.128.1 to 10.12.143.25410.12.143.2554,094
20210.12.144.0/2010.12.144.1 to 10.12.159.25410.12.159.2554,094
20310.12.160.0/2010.12.160.1 to 10.12.175.25410.12.175.2554,094
20410.12.176.0/2010.12.176.1 to 10.12.191.25410.12.191.2554,094
20510.12.192.0/2010.12.192.1 to 10.12.207.25410.12.207.2554,094
20610.12.208.0/2010.12.208.1 to 10.12.223.25410.12.223.2554,094
20710.12.224.0/2010.12.224.1 to 10.12.239.25410.12.239.2554,094
20810.12.240.0/2010.12.240.1 to 10.12.255.25410.12.255.2554,094
20910.13.0.0/2010.13.0.1 to 10.13.15.25410.13.15.2554,094
21010.13.16.0/2010.13.16.1 to 10.13.31.25410.13.31.2554,094
21110.13.32.0/2010.13.32.1 to 10.13.47.25410.13.47.2554,094
21210.13.48.0/2010.13.48.1 to 10.13.63.25410.13.63.2554,094
21310.13.64.0/2010.13.64.1 to 10.13.79.25410.13.79.2554,094
21410.13.80.0/2010.13.80.1 to 10.13.95.25410.13.95.2554,094
21510.13.96.0/2010.13.96.1 to 10.13.111.25410.13.111.2554,094
21610.13.112.0/2010.13.112.1 to 10.13.127.25410.13.127.2554,094
21710.13.128.0/2010.13.128.1 to 10.13.143.25410.13.143.2554,094
21810.13.144.0/2010.13.144.1 to 10.13.159.25410.13.159.2554,094
21910.13.160.0/2010.13.160.1 to 10.13.175.25410.13.175.2554,094
22010.13.176.0/2010.13.176.1 to 10.13.191.25410.13.191.2554,094
22110.13.192.0/2010.13.192.1 to 10.13.207.25410.13.207.2554,094
22210.13.208.0/2010.13.208.1 to 10.13.223.25410.13.223.2554,094
22310.13.224.0/2010.13.224.1 to 10.13.239.25410.13.239.2554,094
22410.13.240.0/2010.13.240.1 to 10.13.255.25410.13.255.2554,094
22510.14.0.0/2010.14.0.1 to 10.14.15.25410.14.15.2554,094
22610.14.16.0/2010.14.16.1 to 10.14.31.25410.14.31.2554,094
22710.14.32.0/2010.14.32.1 to 10.14.47.25410.14.47.2554,094
22810.14.48.0/2010.14.48.1 to 10.14.63.25410.14.63.2554,094
22910.14.64.0/2010.14.64.1 to 10.14.79.25410.14.79.2554,094
23010.14.80.0/2010.14.80.1 to 10.14.95.25410.14.95.2554,094
23110.14.96.0/2010.14.96.1 to 10.14.111.25410.14.111.2554,094
23210.14.112.0/2010.14.112.1 to 10.14.127.25410.14.127.2554,094
23310.14.128.0/2010.14.128.1 to 10.14.143.25410.14.143.2554,094
23410.14.144.0/2010.14.144.1 to 10.14.159.25410.14.159.2554,094
23510.14.160.0/2010.14.160.1 to 10.14.175.25410.14.175.2554,094
23610.14.176.0/2010.14.176.1 to 10.14.191.25410.14.191.2554,094
23710.14.192.0/2010.14.192.1 to 10.14.207.25410.14.207.2554,094
23810.14.208.0/2010.14.208.1 to 10.14.223.25410.14.223.2554,094
23910.14.224.0/2010.14.224.1 to 10.14.239.25410.14.239.2554,094
24010.14.240.0/2010.14.240.1 to 10.14.255.25410.14.255.2554,094
24110.15.0.0/2010.15.0.1 to 10.15.15.25410.15.15.2554,094
24210.15.16.0/2010.15.16.1 to 10.15.31.25410.15.31.2554,094
24310.15.32.0/2010.15.32.1 to 10.15.47.25410.15.47.2554,094
24410.15.48.0/2010.15.48.1 to 10.15.63.25410.15.63.2554,094
24510.15.64.0/2010.15.64.1 to 10.15.79.25410.15.79.2554,094
24610.15.80.0/2010.15.80.1 to 10.15.95.25410.15.95.2554,094
24710.15.96.0/2010.15.96.1 to 10.15.111.25410.15.111.2554,094
24810.15.112.0/2010.15.112.1 to 10.15.127.25410.15.127.2554,094
24910.15.128.0/2010.15.128.1 to 10.15.143.25410.15.143.2554,094
25010.15.144.0/2010.15.144.1 to 10.15.159.25410.15.159.2554,094
25110.15.160.0/2010.15.160.1 to 10.15.175.25410.15.175.2554,094
25210.15.176.0/2010.15.176.1 to 10.15.191.25410.15.191.2554,094
25310.15.192.0/2010.15.192.1 to 10.15.207.25410.15.207.2554,094
25410.15.208.0/2010.15.208.1 to 10.15.223.25410.15.223.2554,094
25510.15.224.0/2010.15.224.1 to 10.15.239.25410.15.239.2554,094
25610.15.240.0/2010.15.240.1 to 10.15.255.25410.15.255.2554,094

IPv4 CIDR reference (/0 to /32)

IPv4 prefix lengths
PrefixSubnet maskWildcardAddressesUsable hostsSizeTypical use
/00.0.0.0255.255.255.2554,294,967,2964,294,967,29416,777,216 × /24
/1128.0.0.0127.255.255.2552,147,483,6482,147,483,6468,388,608 × /24
/2192.0.0.063.255.255.2551,073,741,8241,073,741,8224,194,304 × /24
/3224.0.0.031.255.255.255536,870,912536,870,9102,097,152 × /24
/4240.0.0.015.255.255.255268,435,456268,435,4541,048,576 × /24
/5248.0.0.07.255.255.255134,217,728134,217,726524,288 × /24
/6252.0.0.03.255.255.25567,108,86467,108,862262,144 × /24
/7254.0.0.01.255.255.25533,554,43233,554,430131,072 × /24
/8255.0.0.00.255.255.25516,777,21616,777,21465,536 × /24Old class A; 10.0.0.0/8
/9255.128.0.00.127.255.2558,388,6088,388,60632,768 × /24
/10255.192.0.00.63.255.2554,194,3044,194,30216,384 × /24
/11255.224.0.00.31.255.2552,097,1522,097,1508,192 × /24
/12255.240.0.00.15.255.2551,048,5761,048,5744,096 × /24172.16.0.0/12
/13255.248.0.00.7.255.255524,288524,2862,048 × /24
/14255.252.0.00.3.255.255262,144262,1421,024 × /24
/15255.254.0.00.1.255.255131,072131,070512 × /24
/16255.255.0.00.0.255.25565,53665,534256 × /24Old class B; 192.168.0.0/16
/17255.255.128.00.0.127.25532,76832,766128 × /24
/18255.255.192.00.0.63.25516,38416,38264 × /24
/19255.255.224.00.0.31.2558,1928,19032 × /24
/20255.255.240.00.0.15.2554,0964,09416 × /24
/21255.255.248.00.0.7.2552,0482,0468 × /24
/22255.255.252.00.0.3.2551,0241,0224 × /24Large office or guest Wi-Fi (1,022 hosts)
/23255.255.254.00.0.1.2555125102 × /24Larger office LAN (510 hosts)
/24255.255.255.00.0.0.2552562541 × /24Typical office LAN (old class C)
/25255.255.255.1280.0.0.1271281261/2 of a /24Smaller LAN or VLAN
/26255.255.255.1920.0.0.6364621/4 of a /24Smaller LAN or VLAN
/27255.255.255.2240.0.0.3132301/8 of a /24Small VLAN, phones, cameras
/28255.255.255.2400.0.0.1516141/16 of a /24Small VLAN, phones, cameras
/29255.255.255.2480.0.0.7861/32 of a /24Small fixed public block (5 usable)
/30255.255.255.2520.0.0.3421/64 of a /24Point-to-point (old style)
/31255.255.255.2540.0.0.1221/128 of a /24Point-to-point link (RFC 3021)
/32255.255.255.2550.0.0.0111/256 of a /24One host

IPv6 prefix reference

IPv6 prefix lengths
PrefixAddresses/64 LANs/48 sitesNibbleTypical use
/342,535,295,865,117,307,932,921,825,928,971,026,432 (2^125)2,305,843,009,213,693,95235,184,372,088,832NoAll global unicast (2000::/3)
/165,192,296,858,534,827,628,530,496,329,220,096 (2^112)281,474,976,710,6564,294,967,296Yes
/20324,518,553,658,426,726,783,156,020,576,256 (2^108)17,592,186,044,416268,435,456YesLarge provider allocation (RIPE minimum for some)
/29633,825,300,114,114,700,748,351,602,688 (2^99)34,359,738,368524,288NoRIPE allocation to a provider (often)
/3279,228,162,514,264,337,593,543,950,336 (2^96)4,294,967,29665,536YesProvider allocation (RIPE default)
/364,951,760,157,141,521,099,596,496,896 (2^92)268,435,4564,096Yes
/40309,485,009,821,345,068,724,781,056 (2^88)16,777,216256Yes
/4419,342,813,113,834,066,795,298,816 (2^84)1,048,57616Yes
/481,208,925,819,614,629,174,706,176 (2^80)65,5361YesOne site or organisation (RIPE PI / assignment)
/5275,557,863,725,914,323,419,136 (2^76)4,096Yes
/564,722,366,482,869,645,213,696 (2^72)256YesSmall site or home (common provider assignment)
/60295,147,905,179,352,825,856 (2^68)16YesSome home broadband (16 LANs)
/6418,446,744,073,709,551,616 (2^64)1YesOne LAN or VLAN (needed for SLAAC)
/7272,057,594,037,927,936 (2^56)1/256 of a /64Yes
/80281,474,976,710,656 (2^48)1/65,536 of a /64Yes
/964,294,967,2961/4,294,967,296 of a /64YesEmbeds an IPv4 address (NAT64)
/11265,5361/281,474,976,710,656 of a /64Yes
/1202561/72,057,594,037,927,936 of a /64Yes
/124161/1,152,921,504,606,846,976 of a /64Yes
/12641/4,611,686,018,427,387,904 of a /64No
/12721/9,223,372,036,854,775,808 of a /64NoPoint-to-point link (RFC 6164)
/12811/18,446,744,073,709,551,616 of a /64YesOne host or loopback

Private and special ranges

IPv4

Special-purpose ranges
RangeNameWhat it is
255.255.255.255/32Limited broadcastEvery host on the local network
0.0.0.0/8This networkNot routed; 0.0.0.0 means "any address" in settings
10.0.0.0/8Private (RFC 1918)Office and home networks; not routed on the internet
100.64.0.0/10Shared address space (CGNAT)Used by providers behind carrier-grade NAT (RFC 6598)
127.0.0.0/8LoopbackThis computer
169.254.0.0/16Link-local (APIPA)Self-assigned when no DHCP server answers
172.16.0.0/12Private (RFC 1918)Office and home networks; not routed on the internet
192.0.0.0/24IETF protocol assignmentsSpecial uses such as DS-Lite
192.0.2.0/24Documentation (TEST-NET-1)For examples; never used on a network
192.88.99.0/246to4 relay (deprecated)Formerly anycast for 6to4
192.168.0.0/16Private (RFC 1918)Office and home networks; not routed on the internet
198.18.0.0/15BenchmarkingNetwork equipment testing (RFC 2544)
198.51.100.0/24Documentation (TEST-NET-2)For examples; never used on a network
203.0.113.0/24Documentation (TEST-NET-3)For examples; never used on a network
224.0.0.0/4MulticastOne-to-many traffic, such as IPTV and routing protocols
240.0.0.0/4ReservedFuture use; not usable on most systems

IPv6

Special-purpose ranges
RangeNameWhat it is
::/128UnspecifiedNo address; :: means "any address" in settings
::1/128LoopbackThis computer
::ffff:0:0/96IPv4-mappedAn IPv4 address written as IPv6
64:ff9b::/96NAT64IPv4 addresses reached through a NAT64 gateway
100::/64Discard onlyTraffic sent here is dropped (RFC 6666)
2001:db8::/32DocumentationFor examples; never used on a network
2001::/32TeredoIPv6 tunnelled over IPv4 UDP
2002::/166to4IPv6 tunnelled over IPv4 (largely retired)
3fff::/20DocumentationFor examples (RFC 9637)
fc00::/7Unique local (ULA)Private IPv6, like RFC 1918; usually fd00::/8
fe80::/10Link-localEvery IPv6 interface has one; not routed
ff00::/8MulticastOne-to-many traffic; replaces broadcast
2000::/3Global unicastPublic internet addresses

About this tool

A network is written as an address and a prefix length, such as 192.168.1.0/24: the first 24 bits name the network and the rest number the devices on it. The calculator works out where the network starts and ends, how many devices it holds, its subnet and wildcard masks, and the reverse DNS zone to ask your provider for.

It also splits a network into equal smaller ones (one per VLAN or site), turns a range of addresses into the fewest CIDR blocks for a firewall rule, and lists every IPv4 prefix length and the common IPv6 ones in reference tables.

Common questions

Why are two addresses lost in every IPv4 subnet?

The first address names the network and the last is the broadcast address, so a /24 has 256 addresses but 254 for devices. A /31 (a link between two routers) and a /32 (one host) are the exceptions.

What size of IPv6 network should a LAN use?

Always /64. Devices pick their own address within it (SLAAC), which needs the full 64 bits. A site usually gets a /48 or /56 from its provider, which holds 65,536 or 256 LANs.

What is a wildcard mask?

The subnet mask turned inside out: 255.255.255.0 becomes 0.0.0.255. Cisco access lists and OSPF use it to say which bits must match.

Which ranges can I use inside an office?

IPv4: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. IPv6: unique local addresses from fd00::/8, though most networks use the public prefix from their provider.