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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.

Network41.0.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
41.0.0.0
Broadcast address
41.63.255.255
First usable
41.0.0.1
Last usable
41.63.255.254
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
Public public
Old class
A (default /8)
As numbers
Hex 29000000 · Integer 687865856 to 692060159
Reverse DNS zones
0.41.in-addr.arpa
1.41.in-addr.arpa
2.41.in-addr.arpa
3.41.in-addr.arpa
4.41.in-addr.arpa
5.41.in-addr.arpa
6.41.in-addr.arpa
7.41.in-addr.arpa
8.41.in-addr.arpa
9.41.in-addr.arpa
10.41.in-addr.arpa
11.41.in-addr.arpa
12.41.in-addr.arpa
13.41.in-addr.arpa
14.41.in-addr.arpa
15.41.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
Address00101001.00000000.00000000.0000000041.0.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network00101001.00000000.00000000.0000000041.0.0.0
Broadcast00101001.00111111.11111111.1111111141.63.255.255
Split into smaller subnets/22
/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)

41.0.0.0/10 makes 4,096 subnets of /22; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
141.0.0.0/2241.0.0.1 to 41.0.3.25441.0.3.2551,022
241.0.4.0/2241.0.4.1 to 41.0.7.25441.0.7.2551,022
341.0.8.0/2241.0.8.1 to 41.0.11.25441.0.11.2551,022
441.0.12.0/2241.0.12.1 to 41.0.15.25441.0.15.2551,022
541.0.16.0/2241.0.16.1 to 41.0.19.25441.0.19.2551,022
641.0.20.0/2241.0.20.1 to 41.0.23.25441.0.23.2551,022
741.0.24.0/2241.0.24.1 to 41.0.27.25441.0.27.2551,022
841.0.28.0/2241.0.28.1 to 41.0.31.25441.0.31.2551,022
941.0.32.0/2241.0.32.1 to 41.0.35.25441.0.35.2551,022
1041.0.36.0/2241.0.36.1 to 41.0.39.25441.0.39.2551,022
1141.0.40.0/2241.0.40.1 to 41.0.43.25441.0.43.2551,022
1241.0.44.0/2241.0.44.1 to 41.0.47.25441.0.47.2551,022
1341.0.48.0/2241.0.48.1 to 41.0.51.25441.0.51.2551,022
1441.0.52.0/2241.0.52.1 to 41.0.55.25441.0.55.2551,022
1541.0.56.0/2241.0.56.1 to 41.0.59.25441.0.59.2551,022
1641.0.60.0/2241.0.60.1 to 41.0.63.25441.0.63.2551,022
1741.0.64.0/2241.0.64.1 to 41.0.67.25441.0.67.2551,022
1841.0.68.0/2241.0.68.1 to 41.0.71.25441.0.71.2551,022
1941.0.72.0/2241.0.72.1 to 41.0.75.25441.0.75.2551,022
2041.0.76.0/2241.0.76.1 to 41.0.79.25441.0.79.2551,022
2141.0.80.0/2241.0.80.1 to 41.0.83.25441.0.83.2551,022
2241.0.84.0/2241.0.84.1 to 41.0.87.25441.0.87.2551,022
2341.0.88.0/2241.0.88.1 to 41.0.91.25441.0.91.2551,022
2441.0.92.0/2241.0.92.1 to 41.0.95.25441.0.95.2551,022
2541.0.96.0/2241.0.96.1 to 41.0.99.25441.0.99.2551,022
2641.0.100.0/2241.0.100.1 to 41.0.103.25441.0.103.2551,022
2741.0.104.0/2241.0.104.1 to 41.0.107.25441.0.107.2551,022
2841.0.108.0/2241.0.108.1 to 41.0.111.25441.0.111.2551,022
2941.0.112.0/2241.0.112.1 to 41.0.115.25441.0.115.2551,022
3041.0.116.0/2241.0.116.1 to 41.0.119.25441.0.119.2551,022
3141.0.120.0/2241.0.120.1 to 41.0.123.25441.0.123.2551,022
3241.0.124.0/2241.0.124.1 to 41.0.127.25441.0.127.2551,022
3341.0.128.0/2241.0.128.1 to 41.0.131.25441.0.131.2551,022
3441.0.132.0/2241.0.132.1 to 41.0.135.25441.0.135.2551,022
3541.0.136.0/2241.0.136.1 to 41.0.139.25441.0.139.2551,022
3641.0.140.0/2241.0.140.1 to 41.0.143.25441.0.143.2551,022
3741.0.144.0/2241.0.144.1 to 41.0.147.25441.0.147.2551,022
3841.0.148.0/2241.0.148.1 to 41.0.151.25441.0.151.2551,022
3941.0.152.0/2241.0.152.1 to 41.0.155.25441.0.155.2551,022
4041.0.156.0/2241.0.156.1 to 41.0.159.25441.0.159.2551,022
4141.0.160.0/2241.0.160.1 to 41.0.163.25441.0.163.2551,022
4241.0.164.0/2241.0.164.1 to 41.0.167.25441.0.167.2551,022
4341.0.168.0/2241.0.168.1 to 41.0.171.25441.0.171.2551,022
4441.0.172.0/2241.0.172.1 to 41.0.175.25441.0.175.2551,022
4541.0.176.0/2241.0.176.1 to 41.0.179.25441.0.179.2551,022
4641.0.180.0/2241.0.180.1 to 41.0.183.25441.0.183.2551,022
4741.0.184.0/2241.0.184.1 to 41.0.187.25441.0.187.2551,022
4841.0.188.0/2241.0.188.1 to 41.0.191.25441.0.191.2551,022
4941.0.192.0/2241.0.192.1 to 41.0.195.25441.0.195.2551,022
5041.0.196.0/2241.0.196.1 to 41.0.199.25441.0.199.2551,022
5141.0.200.0/2241.0.200.1 to 41.0.203.25441.0.203.2551,022
5241.0.204.0/2241.0.204.1 to 41.0.207.25441.0.207.2551,022
5341.0.208.0/2241.0.208.1 to 41.0.211.25441.0.211.2551,022
5441.0.212.0/2241.0.212.1 to 41.0.215.25441.0.215.2551,022
5541.0.216.0/2241.0.216.1 to 41.0.219.25441.0.219.2551,022
5641.0.220.0/2241.0.220.1 to 41.0.223.25441.0.223.2551,022
5741.0.224.0/2241.0.224.1 to 41.0.227.25441.0.227.2551,022
5841.0.228.0/2241.0.228.1 to 41.0.231.25441.0.231.2551,022
5941.0.232.0/2241.0.232.1 to 41.0.235.25441.0.235.2551,022
6041.0.236.0/2241.0.236.1 to 41.0.239.25441.0.239.2551,022
6141.0.240.0/2241.0.240.1 to 41.0.243.25441.0.243.2551,022
6241.0.244.0/2241.0.244.1 to 41.0.247.25441.0.247.2551,022
6341.0.248.0/2241.0.248.1 to 41.0.251.25441.0.251.2551,022
6441.0.252.0/2241.0.252.1 to 41.0.255.25441.0.255.2551,022
6541.1.0.0/2241.1.0.1 to 41.1.3.25441.1.3.2551,022
6641.1.4.0/2241.1.4.1 to 41.1.7.25441.1.7.2551,022
6741.1.8.0/2241.1.8.1 to 41.1.11.25441.1.11.2551,022
6841.1.12.0/2241.1.12.1 to 41.1.15.25441.1.15.2551,022
6941.1.16.0/2241.1.16.1 to 41.1.19.25441.1.19.2551,022
7041.1.20.0/2241.1.20.1 to 41.1.23.25441.1.23.2551,022
7141.1.24.0/2241.1.24.1 to 41.1.27.25441.1.27.2551,022
7241.1.28.0/2241.1.28.1 to 41.1.31.25441.1.31.2551,022
7341.1.32.0/2241.1.32.1 to 41.1.35.25441.1.35.2551,022
7441.1.36.0/2241.1.36.1 to 41.1.39.25441.1.39.2551,022
7541.1.40.0/2241.1.40.1 to 41.1.43.25441.1.43.2551,022
7641.1.44.0/2241.1.44.1 to 41.1.47.25441.1.47.2551,022
7741.1.48.0/2241.1.48.1 to 41.1.51.25441.1.51.2551,022
7841.1.52.0/2241.1.52.1 to 41.1.55.25441.1.55.2551,022
7941.1.56.0/2241.1.56.1 to 41.1.59.25441.1.59.2551,022
8041.1.60.0/2241.1.60.1 to 41.1.63.25441.1.63.2551,022
8141.1.64.0/2241.1.64.1 to 41.1.67.25441.1.67.2551,022
8241.1.68.0/2241.1.68.1 to 41.1.71.25441.1.71.2551,022
8341.1.72.0/2241.1.72.1 to 41.1.75.25441.1.75.2551,022
8441.1.76.0/2241.1.76.1 to 41.1.79.25441.1.79.2551,022
8541.1.80.0/2241.1.80.1 to 41.1.83.25441.1.83.2551,022
8641.1.84.0/2241.1.84.1 to 41.1.87.25441.1.87.2551,022
8741.1.88.0/2241.1.88.1 to 41.1.91.25441.1.91.2551,022
8841.1.92.0/2241.1.92.1 to 41.1.95.25441.1.95.2551,022
8941.1.96.0/2241.1.96.1 to 41.1.99.25441.1.99.2551,022
9041.1.100.0/2241.1.100.1 to 41.1.103.25441.1.103.2551,022
9141.1.104.0/2241.1.104.1 to 41.1.107.25441.1.107.2551,022
9241.1.108.0/2241.1.108.1 to 41.1.111.25441.1.111.2551,022
9341.1.112.0/2241.1.112.1 to 41.1.115.25441.1.115.2551,022
9441.1.116.0/2241.1.116.1 to 41.1.119.25441.1.119.2551,022
9541.1.120.0/2241.1.120.1 to 41.1.123.25441.1.123.2551,022
9641.1.124.0/2241.1.124.1 to 41.1.127.25441.1.127.2551,022
9741.1.128.0/2241.1.128.1 to 41.1.131.25441.1.131.2551,022
9841.1.132.0/2241.1.132.1 to 41.1.135.25441.1.135.2551,022
9941.1.136.0/2241.1.136.1 to 41.1.139.25441.1.139.2551,022
10041.1.140.0/2241.1.140.1 to 41.1.143.25441.1.143.2551,022
10141.1.144.0/2241.1.144.1 to 41.1.147.25441.1.147.2551,022
10241.1.148.0/2241.1.148.1 to 41.1.151.25441.1.151.2551,022
10341.1.152.0/2241.1.152.1 to 41.1.155.25441.1.155.2551,022
10441.1.156.0/2241.1.156.1 to 41.1.159.25441.1.159.2551,022
10541.1.160.0/2241.1.160.1 to 41.1.163.25441.1.163.2551,022
10641.1.164.0/2241.1.164.1 to 41.1.167.25441.1.167.2551,022
10741.1.168.0/2241.1.168.1 to 41.1.171.25441.1.171.2551,022
10841.1.172.0/2241.1.172.1 to 41.1.175.25441.1.175.2551,022
10941.1.176.0/2241.1.176.1 to 41.1.179.25441.1.179.2551,022
11041.1.180.0/2241.1.180.1 to 41.1.183.25441.1.183.2551,022
11141.1.184.0/2241.1.184.1 to 41.1.187.25441.1.187.2551,022
11241.1.188.0/2241.1.188.1 to 41.1.191.25441.1.191.2551,022
11341.1.192.0/2241.1.192.1 to 41.1.195.25441.1.195.2551,022
11441.1.196.0/2241.1.196.1 to 41.1.199.25441.1.199.2551,022
11541.1.200.0/2241.1.200.1 to 41.1.203.25441.1.203.2551,022
11641.1.204.0/2241.1.204.1 to 41.1.207.25441.1.207.2551,022
11741.1.208.0/2241.1.208.1 to 41.1.211.25441.1.211.2551,022
11841.1.212.0/2241.1.212.1 to 41.1.215.25441.1.215.2551,022
11941.1.216.0/2241.1.216.1 to 41.1.219.25441.1.219.2551,022
12041.1.220.0/2241.1.220.1 to 41.1.223.25441.1.223.2551,022
12141.1.224.0/2241.1.224.1 to 41.1.227.25441.1.227.2551,022
12241.1.228.0/2241.1.228.1 to 41.1.231.25441.1.231.2551,022
12341.1.232.0/2241.1.232.1 to 41.1.235.25441.1.235.2551,022
12441.1.236.0/2241.1.236.1 to 41.1.239.25441.1.239.2551,022
12541.1.240.0/2241.1.240.1 to 41.1.243.25441.1.243.2551,022
12641.1.244.0/2241.1.244.1 to 41.1.247.25441.1.247.2551,022
12741.1.248.0/2241.1.248.1 to 41.1.251.25441.1.251.2551,022
12841.1.252.0/2241.1.252.1 to 41.1.255.25441.1.255.2551,022
12941.2.0.0/2241.2.0.1 to 41.2.3.25441.2.3.2551,022
13041.2.4.0/2241.2.4.1 to 41.2.7.25441.2.7.2551,022
13141.2.8.0/2241.2.8.1 to 41.2.11.25441.2.11.2551,022
13241.2.12.0/2241.2.12.1 to 41.2.15.25441.2.15.2551,022
13341.2.16.0/2241.2.16.1 to 41.2.19.25441.2.19.2551,022
13441.2.20.0/2241.2.20.1 to 41.2.23.25441.2.23.2551,022
13541.2.24.0/2241.2.24.1 to 41.2.27.25441.2.27.2551,022
13641.2.28.0/2241.2.28.1 to 41.2.31.25441.2.31.2551,022
13741.2.32.0/2241.2.32.1 to 41.2.35.25441.2.35.2551,022
13841.2.36.0/2241.2.36.1 to 41.2.39.25441.2.39.2551,022
13941.2.40.0/2241.2.40.1 to 41.2.43.25441.2.43.2551,022
14041.2.44.0/2241.2.44.1 to 41.2.47.25441.2.47.2551,022
14141.2.48.0/2241.2.48.1 to 41.2.51.25441.2.51.2551,022
14241.2.52.0/2241.2.52.1 to 41.2.55.25441.2.55.2551,022
14341.2.56.0/2241.2.56.1 to 41.2.59.25441.2.59.2551,022
14441.2.60.0/2241.2.60.1 to 41.2.63.25441.2.63.2551,022
14541.2.64.0/2241.2.64.1 to 41.2.67.25441.2.67.2551,022
14641.2.68.0/2241.2.68.1 to 41.2.71.25441.2.71.2551,022
14741.2.72.0/2241.2.72.1 to 41.2.75.25441.2.75.2551,022
14841.2.76.0/2241.2.76.1 to 41.2.79.25441.2.79.2551,022
14941.2.80.0/2241.2.80.1 to 41.2.83.25441.2.83.2551,022
15041.2.84.0/2241.2.84.1 to 41.2.87.25441.2.87.2551,022
15141.2.88.0/2241.2.88.1 to 41.2.91.25441.2.91.2551,022
15241.2.92.0/2241.2.92.1 to 41.2.95.25441.2.95.2551,022
15341.2.96.0/2241.2.96.1 to 41.2.99.25441.2.99.2551,022
15441.2.100.0/2241.2.100.1 to 41.2.103.25441.2.103.2551,022
15541.2.104.0/2241.2.104.1 to 41.2.107.25441.2.107.2551,022
15641.2.108.0/2241.2.108.1 to 41.2.111.25441.2.111.2551,022
15741.2.112.0/2241.2.112.1 to 41.2.115.25441.2.115.2551,022
15841.2.116.0/2241.2.116.1 to 41.2.119.25441.2.119.2551,022
15941.2.120.0/2241.2.120.1 to 41.2.123.25441.2.123.2551,022
16041.2.124.0/2241.2.124.1 to 41.2.127.25441.2.127.2551,022
16141.2.128.0/2241.2.128.1 to 41.2.131.25441.2.131.2551,022
16241.2.132.0/2241.2.132.1 to 41.2.135.25441.2.135.2551,022
16341.2.136.0/2241.2.136.1 to 41.2.139.25441.2.139.2551,022
16441.2.140.0/2241.2.140.1 to 41.2.143.25441.2.143.2551,022
16541.2.144.0/2241.2.144.1 to 41.2.147.25441.2.147.2551,022
16641.2.148.0/2241.2.148.1 to 41.2.151.25441.2.151.2551,022
16741.2.152.0/2241.2.152.1 to 41.2.155.25441.2.155.2551,022
16841.2.156.0/2241.2.156.1 to 41.2.159.25441.2.159.2551,022
16941.2.160.0/2241.2.160.1 to 41.2.163.25441.2.163.2551,022
17041.2.164.0/2241.2.164.1 to 41.2.167.25441.2.167.2551,022
17141.2.168.0/2241.2.168.1 to 41.2.171.25441.2.171.2551,022
17241.2.172.0/2241.2.172.1 to 41.2.175.25441.2.175.2551,022
17341.2.176.0/2241.2.176.1 to 41.2.179.25441.2.179.2551,022
17441.2.180.0/2241.2.180.1 to 41.2.183.25441.2.183.2551,022
17541.2.184.0/2241.2.184.1 to 41.2.187.25441.2.187.2551,022
17641.2.188.0/2241.2.188.1 to 41.2.191.25441.2.191.2551,022
17741.2.192.0/2241.2.192.1 to 41.2.195.25441.2.195.2551,022
17841.2.196.0/2241.2.196.1 to 41.2.199.25441.2.199.2551,022
17941.2.200.0/2241.2.200.1 to 41.2.203.25441.2.203.2551,022
18041.2.204.0/2241.2.204.1 to 41.2.207.25441.2.207.2551,022
18141.2.208.0/2241.2.208.1 to 41.2.211.25441.2.211.2551,022
18241.2.212.0/2241.2.212.1 to 41.2.215.25441.2.215.2551,022
18341.2.216.0/2241.2.216.1 to 41.2.219.25441.2.219.2551,022
18441.2.220.0/2241.2.220.1 to 41.2.223.25441.2.223.2551,022
18541.2.224.0/2241.2.224.1 to 41.2.227.25441.2.227.2551,022
18641.2.228.0/2241.2.228.1 to 41.2.231.25441.2.231.2551,022
18741.2.232.0/2241.2.232.1 to 41.2.235.25441.2.235.2551,022
18841.2.236.0/2241.2.236.1 to 41.2.239.25441.2.239.2551,022
18941.2.240.0/2241.2.240.1 to 41.2.243.25441.2.243.2551,022
19041.2.244.0/2241.2.244.1 to 41.2.247.25441.2.247.2551,022
19141.2.248.0/2241.2.248.1 to 41.2.251.25441.2.251.2551,022
19241.2.252.0/2241.2.252.1 to 41.2.255.25441.2.255.2551,022
19341.3.0.0/2241.3.0.1 to 41.3.3.25441.3.3.2551,022
19441.3.4.0/2241.3.4.1 to 41.3.7.25441.3.7.2551,022
19541.3.8.0/2241.3.8.1 to 41.3.11.25441.3.11.2551,022
19641.3.12.0/2241.3.12.1 to 41.3.15.25441.3.15.2551,022
19741.3.16.0/2241.3.16.1 to 41.3.19.25441.3.19.2551,022
19841.3.20.0/2241.3.20.1 to 41.3.23.25441.3.23.2551,022
19941.3.24.0/2241.3.24.1 to 41.3.27.25441.3.27.2551,022
20041.3.28.0/2241.3.28.1 to 41.3.31.25441.3.31.2551,022
20141.3.32.0/2241.3.32.1 to 41.3.35.25441.3.35.2551,022
20241.3.36.0/2241.3.36.1 to 41.3.39.25441.3.39.2551,022
20341.3.40.0/2241.3.40.1 to 41.3.43.25441.3.43.2551,022
20441.3.44.0/2241.3.44.1 to 41.3.47.25441.3.47.2551,022
20541.3.48.0/2241.3.48.1 to 41.3.51.25441.3.51.2551,022
20641.3.52.0/2241.3.52.1 to 41.3.55.25441.3.55.2551,022
20741.3.56.0/2241.3.56.1 to 41.3.59.25441.3.59.2551,022
20841.3.60.0/2241.3.60.1 to 41.3.63.25441.3.63.2551,022
20941.3.64.0/2241.3.64.1 to 41.3.67.25441.3.67.2551,022
21041.3.68.0/2241.3.68.1 to 41.3.71.25441.3.71.2551,022
21141.3.72.0/2241.3.72.1 to 41.3.75.25441.3.75.2551,022
21241.3.76.0/2241.3.76.1 to 41.3.79.25441.3.79.2551,022
21341.3.80.0/2241.3.80.1 to 41.3.83.25441.3.83.2551,022
21441.3.84.0/2241.3.84.1 to 41.3.87.25441.3.87.2551,022
21541.3.88.0/2241.3.88.1 to 41.3.91.25441.3.91.2551,022
21641.3.92.0/2241.3.92.1 to 41.3.95.25441.3.95.2551,022
21741.3.96.0/2241.3.96.1 to 41.3.99.25441.3.99.2551,022
21841.3.100.0/2241.3.100.1 to 41.3.103.25441.3.103.2551,022
21941.3.104.0/2241.3.104.1 to 41.3.107.25441.3.107.2551,022
22041.3.108.0/2241.3.108.1 to 41.3.111.25441.3.111.2551,022
22141.3.112.0/2241.3.112.1 to 41.3.115.25441.3.115.2551,022
22241.3.116.0/2241.3.116.1 to 41.3.119.25441.3.119.2551,022
22341.3.120.0/2241.3.120.1 to 41.3.123.25441.3.123.2551,022
22441.3.124.0/2241.3.124.1 to 41.3.127.25441.3.127.2551,022
22541.3.128.0/2241.3.128.1 to 41.3.131.25441.3.131.2551,022
22641.3.132.0/2241.3.132.1 to 41.3.135.25441.3.135.2551,022
22741.3.136.0/2241.3.136.1 to 41.3.139.25441.3.139.2551,022
22841.3.140.0/2241.3.140.1 to 41.3.143.25441.3.143.2551,022
22941.3.144.0/2241.3.144.1 to 41.3.147.25441.3.147.2551,022
23041.3.148.0/2241.3.148.1 to 41.3.151.25441.3.151.2551,022
23141.3.152.0/2241.3.152.1 to 41.3.155.25441.3.155.2551,022
23241.3.156.0/2241.3.156.1 to 41.3.159.25441.3.159.2551,022
23341.3.160.0/2241.3.160.1 to 41.3.163.25441.3.163.2551,022
23441.3.164.0/2241.3.164.1 to 41.3.167.25441.3.167.2551,022
23541.3.168.0/2241.3.168.1 to 41.3.171.25441.3.171.2551,022
23641.3.172.0/2241.3.172.1 to 41.3.175.25441.3.175.2551,022
23741.3.176.0/2241.3.176.1 to 41.3.179.25441.3.179.2551,022
23841.3.180.0/2241.3.180.1 to 41.3.183.25441.3.183.2551,022
23941.3.184.0/2241.3.184.1 to 41.3.187.25441.3.187.2551,022
24041.3.188.0/2241.3.188.1 to 41.3.191.25441.3.191.2551,022
24141.3.192.0/2241.3.192.1 to 41.3.195.25441.3.195.2551,022
24241.3.196.0/2241.3.196.1 to 41.3.199.25441.3.199.2551,022
24341.3.200.0/2241.3.200.1 to 41.3.203.25441.3.203.2551,022
24441.3.204.0/2241.3.204.1 to 41.3.207.25441.3.207.2551,022
24541.3.208.0/2241.3.208.1 to 41.3.211.25441.3.211.2551,022
24641.3.212.0/2241.3.212.1 to 41.3.215.25441.3.215.2551,022
24741.3.216.0/2241.3.216.1 to 41.3.219.25441.3.219.2551,022
24841.3.220.0/2241.3.220.1 to 41.3.223.25441.3.223.2551,022
24941.3.224.0/2241.3.224.1 to 41.3.227.25441.3.227.2551,022
25041.3.228.0/2241.3.228.1 to 41.3.231.25441.3.231.2551,022
25141.3.232.0/2241.3.232.1 to 41.3.235.25441.3.235.2551,022
25241.3.236.0/2241.3.236.1 to 41.3.239.25441.3.239.2551,022
25341.3.240.0/2241.3.240.1 to 41.3.243.25441.3.243.2551,022
25441.3.244.0/2241.3.244.1 to 41.3.247.25441.3.247.2551,022
25541.3.248.0/2241.3.248.1 to 41.3.251.25441.3.251.2551,022
25641.3.252.0/2241.3.252.1 to 41.3.255.25441.3.255.2551,022

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.