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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.

Network75.192.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
75.192.0.0
Broadcast address
75.255.255.255
First usable
75.192.0.1
Last usable
75.255.255.254
Usable hosts
4,194,302 (4,194,304 less the network and broadcast addresses)
Subnet mask
255.192.0.0
Wildcard mask
0.63.255.255 (Cisco ACLs, OSPF)
Prefix length
/10
Type
Public public
Old class
A (default /8)
As numbers
Hex 4BC00000 · Integer 1270874112 to 1275068415
Reverse DNS zones
192.75.in-addr.arpa
193.75.in-addr.arpa
194.75.in-addr.arpa
195.75.in-addr.arpa
196.75.in-addr.arpa
197.75.in-addr.arpa
198.75.in-addr.arpa
199.75.in-addr.arpa
200.75.in-addr.arpa
201.75.in-addr.arpa
202.75.in-addr.arpa
203.75.in-addr.arpa
204.75.in-addr.arpa
205.75.in-addr.arpa
206.75.in-addr.arpa
207.75.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
Address01001011.11000000.00000000.0000000075.192.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network01001011.11000000.00000000.0000000075.192.0.0
Broadcast01001011.11111111.11111111.1111111175.255.255.255
Split into smaller subnets/21
/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)

75.192.0.0/10 makes 2,048 subnets of /21; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
175.192.0.0/2175.192.0.1 to 75.192.7.25475.192.7.2552,046
275.192.8.0/2175.192.8.1 to 75.192.15.25475.192.15.2552,046
375.192.16.0/2175.192.16.1 to 75.192.23.25475.192.23.2552,046
475.192.24.0/2175.192.24.1 to 75.192.31.25475.192.31.2552,046
575.192.32.0/2175.192.32.1 to 75.192.39.25475.192.39.2552,046
675.192.40.0/2175.192.40.1 to 75.192.47.25475.192.47.2552,046
775.192.48.0/2175.192.48.1 to 75.192.55.25475.192.55.2552,046
875.192.56.0/2175.192.56.1 to 75.192.63.25475.192.63.2552,046
975.192.64.0/2175.192.64.1 to 75.192.71.25475.192.71.2552,046
1075.192.72.0/2175.192.72.1 to 75.192.79.25475.192.79.2552,046
1175.192.80.0/2175.192.80.1 to 75.192.87.25475.192.87.2552,046
1275.192.88.0/2175.192.88.1 to 75.192.95.25475.192.95.2552,046
1375.192.96.0/2175.192.96.1 to 75.192.103.25475.192.103.2552,046
1475.192.104.0/2175.192.104.1 to 75.192.111.25475.192.111.2552,046
1575.192.112.0/2175.192.112.1 to 75.192.119.25475.192.119.2552,046
1675.192.120.0/2175.192.120.1 to 75.192.127.25475.192.127.2552,046
1775.192.128.0/2175.192.128.1 to 75.192.135.25475.192.135.2552,046
1875.192.136.0/2175.192.136.1 to 75.192.143.25475.192.143.2552,046
1975.192.144.0/2175.192.144.1 to 75.192.151.25475.192.151.2552,046
2075.192.152.0/2175.192.152.1 to 75.192.159.25475.192.159.2552,046
2175.192.160.0/2175.192.160.1 to 75.192.167.25475.192.167.2552,046
2275.192.168.0/2175.192.168.1 to 75.192.175.25475.192.175.2552,046
2375.192.176.0/2175.192.176.1 to 75.192.183.25475.192.183.2552,046
2475.192.184.0/2175.192.184.1 to 75.192.191.25475.192.191.2552,046
2575.192.192.0/2175.192.192.1 to 75.192.199.25475.192.199.2552,046
2675.192.200.0/2175.192.200.1 to 75.192.207.25475.192.207.2552,046
2775.192.208.0/2175.192.208.1 to 75.192.215.25475.192.215.2552,046
2875.192.216.0/2175.192.216.1 to 75.192.223.25475.192.223.2552,046
2975.192.224.0/2175.192.224.1 to 75.192.231.25475.192.231.2552,046
3075.192.232.0/2175.192.232.1 to 75.192.239.25475.192.239.2552,046
3175.192.240.0/2175.192.240.1 to 75.192.247.25475.192.247.2552,046
3275.192.248.0/2175.192.248.1 to 75.192.255.25475.192.255.2552,046
3375.193.0.0/2175.193.0.1 to 75.193.7.25475.193.7.2552,046
3475.193.8.0/2175.193.8.1 to 75.193.15.25475.193.15.2552,046
3575.193.16.0/2175.193.16.1 to 75.193.23.25475.193.23.2552,046
3675.193.24.0/2175.193.24.1 to 75.193.31.25475.193.31.2552,046
3775.193.32.0/2175.193.32.1 to 75.193.39.25475.193.39.2552,046
3875.193.40.0/2175.193.40.1 to 75.193.47.25475.193.47.2552,046
3975.193.48.0/2175.193.48.1 to 75.193.55.25475.193.55.2552,046
4075.193.56.0/2175.193.56.1 to 75.193.63.25475.193.63.2552,046
4175.193.64.0/2175.193.64.1 to 75.193.71.25475.193.71.2552,046
4275.193.72.0/2175.193.72.1 to 75.193.79.25475.193.79.2552,046
4375.193.80.0/2175.193.80.1 to 75.193.87.25475.193.87.2552,046
4475.193.88.0/2175.193.88.1 to 75.193.95.25475.193.95.2552,046
4575.193.96.0/2175.193.96.1 to 75.193.103.25475.193.103.2552,046
4675.193.104.0/2175.193.104.1 to 75.193.111.25475.193.111.2552,046
4775.193.112.0/2175.193.112.1 to 75.193.119.25475.193.119.2552,046
4875.193.120.0/2175.193.120.1 to 75.193.127.25475.193.127.2552,046
4975.193.128.0/2175.193.128.1 to 75.193.135.25475.193.135.2552,046
5075.193.136.0/2175.193.136.1 to 75.193.143.25475.193.143.2552,046
5175.193.144.0/2175.193.144.1 to 75.193.151.25475.193.151.2552,046
5275.193.152.0/2175.193.152.1 to 75.193.159.25475.193.159.2552,046
5375.193.160.0/2175.193.160.1 to 75.193.167.25475.193.167.2552,046
5475.193.168.0/2175.193.168.1 to 75.193.175.25475.193.175.2552,046
5575.193.176.0/2175.193.176.1 to 75.193.183.25475.193.183.2552,046
5675.193.184.0/2175.193.184.1 to 75.193.191.25475.193.191.2552,046
5775.193.192.0/2175.193.192.1 to 75.193.199.25475.193.199.2552,046
5875.193.200.0/2175.193.200.1 to 75.193.207.25475.193.207.2552,046
5975.193.208.0/2175.193.208.1 to 75.193.215.25475.193.215.2552,046
6075.193.216.0/2175.193.216.1 to 75.193.223.25475.193.223.2552,046
6175.193.224.0/2175.193.224.1 to 75.193.231.25475.193.231.2552,046
6275.193.232.0/2175.193.232.1 to 75.193.239.25475.193.239.2552,046
6375.193.240.0/2175.193.240.1 to 75.193.247.25475.193.247.2552,046
6475.193.248.0/2175.193.248.1 to 75.193.255.25475.193.255.2552,046
6575.194.0.0/2175.194.0.1 to 75.194.7.25475.194.7.2552,046
6675.194.8.0/2175.194.8.1 to 75.194.15.25475.194.15.2552,046
6775.194.16.0/2175.194.16.1 to 75.194.23.25475.194.23.2552,046
6875.194.24.0/2175.194.24.1 to 75.194.31.25475.194.31.2552,046
6975.194.32.0/2175.194.32.1 to 75.194.39.25475.194.39.2552,046
7075.194.40.0/2175.194.40.1 to 75.194.47.25475.194.47.2552,046
7175.194.48.0/2175.194.48.1 to 75.194.55.25475.194.55.2552,046
7275.194.56.0/2175.194.56.1 to 75.194.63.25475.194.63.2552,046
7375.194.64.0/2175.194.64.1 to 75.194.71.25475.194.71.2552,046
7475.194.72.0/2175.194.72.1 to 75.194.79.25475.194.79.2552,046
7575.194.80.0/2175.194.80.1 to 75.194.87.25475.194.87.2552,046
7675.194.88.0/2175.194.88.1 to 75.194.95.25475.194.95.2552,046
7775.194.96.0/2175.194.96.1 to 75.194.103.25475.194.103.2552,046
7875.194.104.0/2175.194.104.1 to 75.194.111.25475.194.111.2552,046
7975.194.112.0/2175.194.112.1 to 75.194.119.25475.194.119.2552,046
8075.194.120.0/2175.194.120.1 to 75.194.127.25475.194.127.2552,046
8175.194.128.0/2175.194.128.1 to 75.194.135.25475.194.135.2552,046
8275.194.136.0/2175.194.136.1 to 75.194.143.25475.194.143.2552,046
8375.194.144.0/2175.194.144.1 to 75.194.151.25475.194.151.2552,046
8475.194.152.0/2175.194.152.1 to 75.194.159.25475.194.159.2552,046
8575.194.160.0/2175.194.160.1 to 75.194.167.25475.194.167.2552,046
8675.194.168.0/2175.194.168.1 to 75.194.175.25475.194.175.2552,046
8775.194.176.0/2175.194.176.1 to 75.194.183.25475.194.183.2552,046
8875.194.184.0/2175.194.184.1 to 75.194.191.25475.194.191.2552,046
8975.194.192.0/2175.194.192.1 to 75.194.199.25475.194.199.2552,046
9075.194.200.0/2175.194.200.1 to 75.194.207.25475.194.207.2552,046
9175.194.208.0/2175.194.208.1 to 75.194.215.25475.194.215.2552,046
9275.194.216.0/2175.194.216.1 to 75.194.223.25475.194.223.2552,046
9375.194.224.0/2175.194.224.1 to 75.194.231.25475.194.231.2552,046
9475.194.232.0/2175.194.232.1 to 75.194.239.25475.194.239.2552,046
9575.194.240.0/2175.194.240.1 to 75.194.247.25475.194.247.2552,046
9675.194.248.0/2175.194.248.1 to 75.194.255.25475.194.255.2552,046
9775.195.0.0/2175.195.0.1 to 75.195.7.25475.195.7.2552,046
9875.195.8.0/2175.195.8.1 to 75.195.15.25475.195.15.2552,046
9975.195.16.0/2175.195.16.1 to 75.195.23.25475.195.23.2552,046
10075.195.24.0/2175.195.24.1 to 75.195.31.25475.195.31.2552,046
10175.195.32.0/2175.195.32.1 to 75.195.39.25475.195.39.2552,046
10275.195.40.0/2175.195.40.1 to 75.195.47.25475.195.47.2552,046
10375.195.48.0/2175.195.48.1 to 75.195.55.25475.195.55.2552,046
10475.195.56.0/2175.195.56.1 to 75.195.63.25475.195.63.2552,046
10575.195.64.0/2175.195.64.1 to 75.195.71.25475.195.71.2552,046
10675.195.72.0/2175.195.72.1 to 75.195.79.25475.195.79.2552,046
10775.195.80.0/2175.195.80.1 to 75.195.87.25475.195.87.2552,046
10875.195.88.0/2175.195.88.1 to 75.195.95.25475.195.95.2552,046
10975.195.96.0/2175.195.96.1 to 75.195.103.25475.195.103.2552,046
11075.195.104.0/2175.195.104.1 to 75.195.111.25475.195.111.2552,046
11175.195.112.0/2175.195.112.1 to 75.195.119.25475.195.119.2552,046
11275.195.120.0/2175.195.120.1 to 75.195.127.25475.195.127.2552,046
11375.195.128.0/2175.195.128.1 to 75.195.135.25475.195.135.2552,046
11475.195.136.0/2175.195.136.1 to 75.195.143.25475.195.143.2552,046
11575.195.144.0/2175.195.144.1 to 75.195.151.25475.195.151.2552,046
11675.195.152.0/2175.195.152.1 to 75.195.159.25475.195.159.2552,046
11775.195.160.0/2175.195.160.1 to 75.195.167.25475.195.167.2552,046
11875.195.168.0/2175.195.168.1 to 75.195.175.25475.195.175.2552,046
11975.195.176.0/2175.195.176.1 to 75.195.183.25475.195.183.2552,046
12075.195.184.0/2175.195.184.1 to 75.195.191.25475.195.191.2552,046
12175.195.192.0/2175.195.192.1 to 75.195.199.25475.195.199.2552,046
12275.195.200.0/2175.195.200.1 to 75.195.207.25475.195.207.2552,046
12375.195.208.0/2175.195.208.1 to 75.195.215.25475.195.215.2552,046
12475.195.216.0/2175.195.216.1 to 75.195.223.25475.195.223.2552,046
12575.195.224.0/2175.195.224.1 to 75.195.231.25475.195.231.2552,046
12675.195.232.0/2175.195.232.1 to 75.195.239.25475.195.239.2552,046
12775.195.240.0/2175.195.240.1 to 75.195.247.25475.195.247.2552,046
12875.195.248.0/2175.195.248.1 to 75.195.255.25475.195.255.2552,046
12975.196.0.0/2175.196.0.1 to 75.196.7.25475.196.7.2552,046
13075.196.8.0/2175.196.8.1 to 75.196.15.25475.196.15.2552,046
13175.196.16.0/2175.196.16.1 to 75.196.23.25475.196.23.2552,046
13275.196.24.0/2175.196.24.1 to 75.196.31.25475.196.31.2552,046
13375.196.32.0/2175.196.32.1 to 75.196.39.25475.196.39.2552,046
13475.196.40.0/2175.196.40.1 to 75.196.47.25475.196.47.2552,046
13575.196.48.0/2175.196.48.1 to 75.196.55.25475.196.55.2552,046
13675.196.56.0/2175.196.56.1 to 75.196.63.25475.196.63.2552,046
13775.196.64.0/2175.196.64.1 to 75.196.71.25475.196.71.2552,046
13875.196.72.0/2175.196.72.1 to 75.196.79.25475.196.79.2552,046
13975.196.80.0/2175.196.80.1 to 75.196.87.25475.196.87.2552,046
14075.196.88.0/2175.196.88.1 to 75.196.95.25475.196.95.2552,046
14175.196.96.0/2175.196.96.1 to 75.196.103.25475.196.103.2552,046
14275.196.104.0/2175.196.104.1 to 75.196.111.25475.196.111.2552,046
14375.196.112.0/2175.196.112.1 to 75.196.119.25475.196.119.2552,046
14475.196.120.0/2175.196.120.1 to 75.196.127.25475.196.127.2552,046
14575.196.128.0/2175.196.128.1 to 75.196.135.25475.196.135.2552,046
14675.196.136.0/2175.196.136.1 to 75.196.143.25475.196.143.2552,046
14775.196.144.0/2175.196.144.1 to 75.196.151.25475.196.151.2552,046
14875.196.152.0/2175.196.152.1 to 75.196.159.25475.196.159.2552,046
14975.196.160.0/2175.196.160.1 to 75.196.167.25475.196.167.2552,046
15075.196.168.0/2175.196.168.1 to 75.196.175.25475.196.175.2552,046
15175.196.176.0/2175.196.176.1 to 75.196.183.25475.196.183.2552,046
15275.196.184.0/2175.196.184.1 to 75.196.191.25475.196.191.2552,046
15375.196.192.0/2175.196.192.1 to 75.196.199.25475.196.199.2552,046
15475.196.200.0/2175.196.200.1 to 75.196.207.25475.196.207.2552,046
15575.196.208.0/2175.196.208.1 to 75.196.215.25475.196.215.2552,046
15675.196.216.0/2175.196.216.1 to 75.196.223.25475.196.223.2552,046
15775.196.224.0/2175.196.224.1 to 75.196.231.25475.196.231.2552,046
15875.196.232.0/2175.196.232.1 to 75.196.239.25475.196.239.2552,046
15975.196.240.0/2175.196.240.1 to 75.196.247.25475.196.247.2552,046
16075.196.248.0/2175.196.248.1 to 75.196.255.25475.196.255.2552,046
16175.197.0.0/2175.197.0.1 to 75.197.7.25475.197.7.2552,046
16275.197.8.0/2175.197.8.1 to 75.197.15.25475.197.15.2552,046
16375.197.16.0/2175.197.16.1 to 75.197.23.25475.197.23.2552,046
16475.197.24.0/2175.197.24.1 to 75.197.31.25475.197.31.2552,046
16575.197.32.0/2175.197.32.1 to 75.197.39.25475.197.39.2552,046
16675.197.40.0/2175.197.40.1 to 75.197.47.25475.197.47.2552,046
16775.197.48.0/2175.197.48.1 to 75.197.55.25475.197.55.2552,046
16875.197.56.0/2175.197.56.1 to 75.197.63.25475.197.63.2552,046
16975.197.64.0/2175.197.64.1 to 75.197.71.25475.197.71.2552,046
17075.197.72.0/2175.197.72.1 to 75.197.79.25475.197.79.2552,046
17175.197.80.0/2175.197.80.1 to 75.197.87.25475.197.87.2552,046
17275.197.88.0/2175.197.88.1 to 75.197.95.25475.197.95.2552,046
17375.197.96.0/2175.197.96.1 to 75.197.103.25475.197.103.2552,046
17475.197.104.0/2175.197.104.1 to 75.197.111.25475.197.111.2552,046
17575.197.112.0/2175.197.112.1 to 75.197.119.25475.197.119.2552,046
17675.197.120.0/2175.197.120.1 to 75.197.127.25475.197.127.2552,046
17775.197.128.0/2175.197.128.1 to 75.197.135.25475.197.135.2552,046
17875.197.136.0/2175.197.136.1 to 75.197.143.25475.197.143.2552,046
17975.197.144.0/2175.197.144.1 to 75.197.151.25475.197.151.2552,046
18075.197.152.0/2175.197.152.1 to 75.197.159.25475.197.159.2552,046
18175.197.160.0/2175.197.160.1 to 75.197.167.25475.197.167.2552,046
18275.197.168.0/2175.197.168.1 to 75.197.175.25475.197.175.2552,046
18375.197.176.0/2175.197.176.1 to 75.197.183.25475.197.183.2552,046
18475.197.184.0/2175.197.184.1 to 75.197.191.25475.197.191.2552,046
18575.197.192.0/2175.197.192.1 to 75.197.199.25475.197.199.2552,046
18675.197.200.0/2175.197.200.1 to 75.197.207.25475.197.207.2552,046
18775.197.208.0/2175.197.208.1 to 75.197.215.25475.197.215.2552,046
18875.197.216.0/2175.197.216.1 to 75.197.223.25475.197.223.2552,046
18975.197.224.0/2175.197.224.1 to 75.197.231.25475.197.231.2552,046
19075.197.232.0/2175.197.232.1 to 75.197.239.25475.197.239.2552,046
19175.197.240.0/2175.197.240.1 to 75.197.247.25475.197.247.2552,046
19275.197.248.0/2175.197.248.1 to 75.197.255.25475.197.255.2552,046
19375.198.0.0/2175.198.0.1 to 75.198.7.25475.198.7.2552,046
19475.198.8.0/2175.198.8.1 to 75.198.15.25475.198.15.2552,046
19575.198.16.0/2175.198.16.1 to 75.198.23.25475.198.23.2552,046
19675.198.24.0/2175.198.24.1 to 75.198.31.25475.198.31.2552,046
19775.198.32.0/2175.198.32.1 to 75.198.39.25475.198.39.2552,046
19875.198.40.0/2175.198.40.1 to 75.198.47.25475.198.47.2552,046
19975.198.48.0/2175.198.48.1 to 75.198.55.25475.198.55.2552,046
20075.198.56.0/2175.198.56.1 to 75.198.63.25475.198.63.2552,046
20175.198.64.0/2175.198.64.1 to 75.198.71.25475.198.71.2552,046
20275.198.72.0/2175.198.72.1 to 75.198.79.25475.198.79.2552,046
20375.198.80.0/2175.198.80.1 to 75.198.87.25475.198.87.2552,046
20475.198.88.0/2175.198.88.1 to 75.198.95.25475.198.95.2552,046
20575.198.96.0/2175.198.96.1 to 75.198.103.25475.198.103.2552,046
20675.198.104.0/2175.198.104.1 to 75.198.111.25475.198.111.2552,046
20775.198.112.0/2175.198.112.1 to 75.198.119.25475.198.119.2552,046
20875.198.120.0/2175.198.120.1 to 75.198.127.25475.198.127.2552,046
20975.198.128.0/2175.198.128.1 to 75.198.135.25475.198.135.2552,046
21075.198.136.0/2175.198.136.1 to 75.198.143.25475.198.143.2552,046
21175.198.144.0/2175.198.144.1 to 75.198.151.25475.198.151.2552,046
21275.198.152.0/2175.198.152.1 to 75.198.159.25475.198.159.2552,046
21375.198.160.0/2175.198.160.1 to 75.198.167.25475.198.167.2552,046
21475.198.168.0/2175.198.168.1 to 75.198.175.25475.198.175.2552,046
21575.198.176.0/2175.198.176.1 to 75.198.183.25475.198.183.2552,046
21675.198.184.0/2175.198.184.1 to 75.198.191.25475.198.191.2552,046
21775.198.192.0/2175.198.192.1 to 75.198.199.25475.198.199.2552,046
21875.198.200.0/2175.198.200.1 to 75.198.207.25475.198.207.2552,046
21975.198.208.0/2175.198.208.1 to 75.198.215.25475.198.215.2552,046
22075.198.216.0/2175.198.216.1 to 75.198.223.25475.198.223.2552,046
22175.198.224.0/2175.198.224.1 to 75.198.231.25475.198.231.2552,046
22275.198.232.0/2175.198.232.1 to 75.198.239.25475.198.239.2552,046
22375.198.240.0/2175.198.240.1 to 75.198.247.25475.198.247.2552,046
22475.198.248.0/2175.198.248.1 to 75.198.255.25475.198.255.2552,046
22575.199.0.0/2175.199.0.1 to 75.199.7.25475.199.7.2552,046
22675.199.8.0/2175.199.8.1 to 75.199.15.25475.199.15.2552,046
22775.199.16.0/2175.199.16.1 to 75.199.23.25475.199.23.2552,046
22875.199.24.0/2175.199.24.1 to 75.199.31.25475.199.31.2552,046
22975.199.32.0/2175.199.32.1 to 75.199.39.25475.199.39.2552,046
23075.199.40.0/2175.199.40.1 to 75.199.47.25475.199.47.2552,046
23175.199.48.0/2175.199.48.1 to 75.199.55.25475.199.55.2552,046
23275.199.56.0/2175.199.56.1 to 75.199.63.25475.199.63.2552,046
23375.199.64.0/2175.199.64.1 to 75.199.71.25475.199.71.2552,046
23475.199.72.0/2175.199.72.1 to 75.199.79.25475.199.79.2552,046
23575.199.80.0/2175.199.80.1 to 75.199.87.25475.199.87.2552,046
23675.199.88.0/2175.199.88.1 to 75.199.95.25475.199.95.2552,046
23775.199.96.0/2175.199.96.1 to 75.199.103.25475.199.103.2552,046
23875.199.104.0/2175.199.104.1 to 75.199.111.25475.199.111.2552,046
23975.199.112.0/2175.199.112.1 to 75.199.119.25475.199.119.2552,046
24075.199.120.0/2175.199.120.1 to 75.199.127.25475.199.127.2552,046
24175.199.128.0/2175.199.128.1 to 75.199.135.25475.199.135.2552,046
24275.199.136.0/2175.199.136.1 to 75.199.143.25475.199.143.2552,046
24375.199.144.0/2175.199.144.1 to 75.199.151.25475.199.151.2552,046
24475.199.152.0/2175.199.152.1 to 75.199.159.25475.199.159.2552,046
24575.199.160.0/2175.199.160.1 to 75.199.167.25475.199.167.2552,046
24675.199.168.0/2175.199.168.1 to 75.199.175.25475.199.175.2552,046
24775.199.176.0/2175.199.176.1 to 75.199.183.25475.199.183.2552,046
24875.199.184.0/2175.199.184.1 to 75.199.191.25475.199.191.2552,046
24975.199.192.0/2175.199.192.1 to 75.199.199.25475.199.199.2552,046
25075.199.200.0/2175.199.200.1 to 75.199.207.25475.199.207.2552,046
25175.199.208.0/2175.199.208.1 to 75.199.215.25475.199.215.2552,046
25275.199.216.0/2175.199.216.1 to 75.199.223.25475.199.223.2552,046
25375.199.224.0/2175.199.224.1 to 75.199.231.25475.199.231.2552,046
25475.199.232.0/2175.199.232.1 to 75.199.239.25475.199.239.2552,046
25575.199.240.0/2175.199.240.1 to 75.199.247.25475.199.247.2552,046
25675.199.248.0/2175.199.248.1 to 75.199.255.25475.199.255.2552,046

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.