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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.

Network28.0.0.0/6
Usable hosts67,108,862
Subnet mask252.0.0.0
Addresses67,108,864
Network address
28.0.0.0
Broadcast address
31.255.255.255
First usable
28.0.0.1
Last usable
31.255.255.254
Usable hosts
67,108,862 (67,108,864 less the network and broadcast addresses)
Subnet mask
252.0.0.0
Wildcard mask
3.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/6
Type
Public public
Old class
A (default /8)
As numbers
Hex 1C000000 · Integer 469762048 to 536870911
Reverse DNS zones
28.in-addr.arpa
29.in-addr.arpa
30.in-addr.arpa
31.in-addr.arpa
/6 is not on a 8-bit boundary, so it takes 4 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address00011100.00000000.00000000.0000000028.0.0.0
Subnet mask11111100.00000000.00000000.00000000252.0.0.0
Network00011100.00000000.00000000.0000000028.0.0.0
Broadcast00011111.11111111.11111111.1111111131.255.255.255
Split into smaller subnets/14
/7 (2)/8 (4)/9 (8)/10 (16)/11 (32)/12 (64)/13 (128)/14 (256)/15 (512)/16 (1,024)/17 (2,048)/18 (4,096)

28.0.0.0/6 makes 256 subnets of /14.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
128.0.0.0/1428.0.0.1 to 28.3.255.25428.3.255.255262,142
228.4.0.0/1428.4.0.1 to 28.7.255.25428.7.255.255262,142
328.8.0.0/1428.8.0.1 to 28.11.255.25428.11.255.255262,142
428.12.0.0/1428.12.0.1 to 28.15.255.25428.15.255.255262,142
528.16.0.0/1428.16.0.1 to 28.19.255.25428.19.255.255262,142
628.20.0.0/1428.20.0.1 to 28.23.255.25428.23.255.255262,142
728.24.0.0/1428.24.0.1 to 28.27.255.25428.27.255.255262,142
828.28.0.0/1428.28.0.1 to 28.31.255.25428.31.255.255262,142
928.32.0.0/1428.32.0.1 to 28.35.255.25428.35.255.255262,142
1028.36.0.0/1428.36.0.1 to 28.39.255.25428.39.255.255262,142
1128.40.0.0/1428.40.0.1 to 28.43.255.25428.43.255.255262,142
1228.44.0.0/1428.44.0.1 to 28.47.255.25428.47.255.255262,142
1328.48.0.0/1428.48.0.1 to 28.51.255.25428.51.255.255262,142
1428.52.0.0/1428.52.0.1 to 28.55.255.25428.55.255.255262,142
1528.56.0.0/1428.56.0.1 to 28.59.255.25428.59.255.255262,142
1628.60.0.0/1428.60.0.1 to 28.63.255.25428.63.255.255262,142
1728.64.0.0/1428.64.0.1 to 28.67.255.25428.67.255.255262,142
1828.68.0.0/1428.68.0.1 to 28.71.255.25428.71.255.255262,142
1928.72.0.0/1428.72.0.1 to 28.75.255.25428.75.255.255262,142
2028.76.0.0/1428.76.0.1 to 28.79.255.25428.79.255.255262,142
2128.80.0.0/1428.80.0.1 to 28.83.255.25428.83.255.255262,142
2228.84.0.0/1428.84.0.1 to 28.87.255.25428.87.255.255262,142
2328.88.0.0/1428.88.0.1 to 28.91.255.25428.91.255.255262,142
2428.92.0.0/1428.92.0.1 to 28.95.255.25428.95.255.255262,142
2528.96.0.0/1428.96.0.1 to 28.99.255.25428.99.255.255262,142
2628.100.0.0/1428.100.0.1 to 28.103.255.25428.103.255.255262,142
2728.104.0.0/1428.104.0.1 to 28.107.255.25428.107.255.255262,142
2828.108.0.0/1428.108.0.1 to 28.111.255.25428.111.255.255262,142
2928.112.0.0/1428.112.0.1 to 28.115.255.25428.115.255.255262,142
3028.116.0.0/1428.116.0.1 to 28.119.255.25428.119.255.255262,142
3128.120.0.0/1428.120.0.1 to 28.123.255.25428.123.255.255262,142
3228.124.0.0/1428.124.0.1 to 28.127.255.25428.127.255.255262,142
3328.128.0.0/1428.128.0.1 to 28.131.255.25428.131.255.255262,142
3428.132.0.0/1428.132.0.1 to 28.135.255.25428.135.255.255262,142
3528.136.0.0/1428.136.0.1 to 28.139.255.25428.139.255.255262,142
3628.140.0.0/1428.140.0.1 to 28.143.255.25428.143.255.255262,142
3728.144.0.0/1428.144.0.1 to 28.147.255.25428.147.255.255262,142
3828.148.0.0/1428.148.0.1 to 28.151.255.25428.151.255.255262,142
3928.152.0.0/1428.152.0.1 to 28.155.255.25428.155.255.255262,142
4028.156.0.0/1428.156.0.1 to 28.159.255.25428.159.255.255262,142
4128.160.0.0/1428.160.0.1 to 28.163.255.25428.163.255.255262,142
4228.164.0.0/1428.164.0.1 to 28.167.255.25428.167.255.255262,142
4328.168.0.0/1428.168.0.1 to 28.171.255.25428.171.255.255262,142
4428.172.0.0/1428.172.0.1 to 28.175.255.25428.175.255.255262,142
4528.176.0.0/1428.176.0.1 to 28.179.255.25428.179.255.255262,142
4628.180.0.0/1428.180.0.1 to 28.183.255.25428.183.255.255262,142
4728.184.0.0/1428.184.0.1 to 28.187.255.25428.187.255.255262,142
4828.188.0.0/1428.188.0.1 to 28.191.255.25428.191.255.255262,142
4928.192.0.0/1428.192.0.1 to 28.195.255.25428.195.255.255262,142
5028.196.0.0/1428.196.0.1 to 28.199.255.25428.199.255.255262,142
5128.200.0.0/1428.200.0.1 to 28.203.255.25428.203.255.255262,142
5228.204.0.0/1428.204.0.1 to 28.207.255.25428.207.255.255262,142
5328.208.0.0/1428.208.0.1 to 28.211.255.25428.211.255.255262,142
5428.212.0.0/1428.212.0.1 to 28.215.255.25428.215.255.255262,142
5528.216.0.0/1428.216.0.1 to 28.219.255.25428.219.255.255262,142
5628.220.0.0/1428.220.0.1 to 28.223.255.25428.223.255.255262,142
5728.224.0.0/1428.224.0.1 to 28.227.255.25428.227.255.255262,142
5828.228.0.0/1428.228.0.1 to 28.231.255.25428.231.255.255262,142
5928.232.0.0/1428.232.0.1 to 28.235.255.25428.235.255.255262,142
6028.236.0.0/1428.236.0.1 to 28.239.255.25428.239.255.255262,142
6128.240.0.0/1428.240.0.1 to 28.243.255.25428.243.255.255262,142
6228.244.0.0/1428.244.0.1 to 28.247.255.25428.247.255.255262,142
6328.248.0.0/1428.248.0.1 to 28.251.255.25428.251.255.255262,142
6428.252.0.0/1428.252.0.1 to 28.255.255.25428.255.255.255262,142
6529.0.0.0/1429.0.0.1 to 29.3.255.25429.3.255.255262,142
6629.4.0.0/1429.4.0.1 to 29.7.255.25429.7.255.255262,142
6729.8.0.0/1429.8.0.1 to 29.11.255.25429.11.255.255262,142
6829.12.0.0/1429.12.0.1 to 29.15.255.25429.15.255.255262,142
6929.16.0.0/1429.16.0.1 to 29.19.255.25429.19.255.255262,142
7029.20.0.0/1429.20.0.1 to 29.23.255.25429.23.255.255262,142
7129.24.0.0/1429.24.0.1 to 29.27.255.25429.27.255.255262,142
7229.28.0.0/1429.28.0.1 to 29.31.255.25429.31.255.255262,142
7329.32.0.0/1429.32.0.1 to 29.35.255.25429.35.255.255262,142
7429.36.0.0/1429.36.0.1 to 29.39.255.25429.39.255.255262,142
7529.40.0.0/1429.40.0.1 to 29.43.255.25429.43.255.255262,142
7629.44.0.0/1429.44.0.1 to 29.47.255.25429.47.255.255262,142
7729.48.0.0/1429.48.0.1 to 29.51.255.25429.51.255.255262,142
7829.52.0.0/1429.52.0.1 to 29.55.255.25429.55.255.255262,142
7929.56.0.0/1429.56.0.1 to 29.59.255.25429.59.255.255262,142
8029.60.0.0/1429.60.0.1 to 29.63.255.25429.63.255.255262,142
8129.64.0.0/1429.64.0.1 to 29.67.255.25429.67.255.255262,142
8229.68.0.0/1429.68.0.1 to 29.71.255.25429.71.255.255262,142
8329.72.0.0/1429.72.0.1 to 29.75.255.25429.75.255.255262,142
8429.76.0.0/1429.76.0.1 to 29.79.255.25429.79.255.255262,142
8529.80.0.0/1429.80.0.1 to 29.83.255.25429.83.255.255262,142
8629.84.0.0/1429.84.0.1 to 29.87.255.25429.87.255.255262,142
8729.88.0.0/1429.88.0.1 to 29.91.255.25429.91.255.255262,142
8829.92.0.0/1429.92.0.1 to 29.95.255.25429.95.255.255262,142
8929.96.0.0/1429.96.0.1 to 29.99.255.25429.99.255.255262,142
9029.100.0.0/1429.100.0.1 to 29.103.255.25429.103.255.255262,142
9129.104.0.0/1429.104.0.1 to 29.107.255.25429.107.255.255262,142
9229.108.0.0/1429.108.0.1 to 29.111.255.25429.111.255.255262,142
9329.112.0.0/1429.112.0.1 to 29.115.255.25429.115.255.255262,142
9429.116.0.0/1429.116.0.1 to 29.119.255.25429.119.255.255262,142
9529.120.0.0/1429.120.0.1 to 29.123.255.25429.123.255.255262,142
9629.124.0.0/1429.124.0.1 to 29.127.255.25429.127.255.255262,142
9729.128.0.0/1429.128.0.1 to 29.131.255.25429.131.255.255262,142
9829.132.0.0/1429.132.0.1 to 29.135.255.25429.135.255.255262,142
9929.136.0.0/1429.136.0.1 to 29.139.255.25429.139.255.255262,142
10029.140.0.0/1429.140.0.1 to 29.143.255.25429.143.255.255262,142
10129.144.0.0/1429.144.0.1 to 29.147.255.25429.147.255.255262,142
10229.148.0.0/1429.148.0.1 to 29.151.255.25429.151.255.255262,142
10329.152.0.0/1429.152.0.1 to 29.155.255.25429.155.255.255262,142
10429.156.0.0/1429.156.0.1 to 29.159.255.25429.159.255.255262,142
10529.160.0.0/1429.160.0.1 to 29.163.255.25429.163.255.255262,142
10629.164.0.0/1429.164.0.1 to 29.167.255.25429.167.255.255262,142
10729.168.0.0/1429.168.0.1 to 29.171.255.25429.171.255.255262,142
10829.172.0.0/1429.172.0.1 to 29.175.255.25429.175.255.255262,142
10929.176.0.0/1429.176.0.1 to 29.179.255.25429.179.255.255262,142
11029.180.0.0/1429.180.0.1 to 29.183.255.25429.183.255.255262,142
11129.184.0.0/1429.184.0.1 to 29.187.255.25429.187.255.255262,142
11229.188.0.0/1429.188.0.1 to 29.191.255.25429.191.255.255262,142
11329.192.0.0/1429.192.0.1 to 29.195.255.25429.195.255.255262,142
11429.196.0.0/1429.196.0.1 to 29.199.255.25429.199.255.255262,142
11529.200.0.0/1429.200.0.1 to 29.203.255.25429.203.255.255262,142
11629.204.0.0/1429.204.0.1 to 29.207.255.25429.207.255.255262,142
11729.208.0.0/1429.208.0.1 to 29.211.255.25429.211.255.255262,142
11829.212.0.0/1429.212.0.1 to 29.215.255.25429.215.255.255262,142
11929.216.0.0/1429.216.0.1 to 29.219.255.25429.219.255.255262,142
12029.220.0.0/1429.220.0.1 to 29.223.255.25429.223.255.255262,142
12129.224.0.0/1429.224.0.1 to 29.227.255.25429.227.255.255262,142
12229.228.0.0/1429.228.0.1 to 29.231.255.25429.231.255.255262,142
12329.232.0.0/1429.232.0.1 to 29.235.255.25429.235.255.255262,142
12429.236.0.0/1429.236.0.1 to 29.239.255.25429.239.255.255262,142
12529.240.0.0/1429.240.0.1 to 29.243.255.25429.243.255.255262,142
12629.244.0.0/1429.244.0.1 to 29.247.255.25429.247.255.255262,142
12729.248.0.0/1429.248.0.1 to 29.251.255.25429.251.255.255262,142
12829.252.0.0/1429.252.0.1 to 29.255.255.25429.255.255.255262,142
12930.0.0.0/1430.0.0.1 to 30.3.255.25430.3.255.255262,142
13030.4.0.0/1430.4.0.1 to 30.7.255.25430.7.255.255262,142
13130.8.0.0/1430.8.0.1 to 30.11.255.25430.11.255.255262,142
13230.12.0.0/1430.12.0.1 to 30.15.255.25430.15.255.255262,142
13330.16.0.0/1430.16.0.1 to 30.19.255.25430.19.255.255262,142
13430.20.0.0/1430.20.0.1 to 30.23.255.25430.23.255.255262,142
13530.24.0.0/1430.24.0.1 to 30.27.255.25430.27.255.255262,142
13630.28.0.0/1430.28.0.1 to 30.31.255.25430.31.255.255262,142
13730.32.0.0/1430.32.0.1 to 30.35.255.25430.35.255.255262,142
13830.36.0.0/1430.36.0.1 to 30.39.255.25430.39.255.255262,142
13930.40.0.0/1430.40.0.1 to 30.43.255.25430.43.255.255262,142
14030.44.0.0/1430.44.0.1 to 30.47.255.25430.47.255.255262,142
14130.48.0.0/1430.48.0.1 to 30.51.255.25430.51.255.255262,142
14230.52.0.0/1430.52.0.1 to 30.55.255.25430.55.255.255262,142
14330.56.0.0/1430.56.0.1 to 30.59.255.25430.59.255.255262,142
14430.60.0.0/1430.60.0.1 to 30.63.255.25430.63.255.255262,142
14530.64.0.0/1430.64.0.1 to 30.67.255.25430.67.255.255262,142
14630.68.0.0/1430.68.0.1 to 30.71.255.25430.71.255.255262,142
14730.72.0.0/1430.72.0.1 to 30.75.255.25430.75.255.255262,142
14830.76.0.0/1430.76.0.1 to 30.79.255.25430.79.255.255262,142
14930.80.0.0/1430.80.0.1 to 30.83.255.25430.83.255.255262,142
15030.84.0.0/1430.84.0.1 to 30.87.255.25430.87.255.255262,142
15130.88.0.0/1430.88.0.1 to 30.91.255.25430.91.255.255262,142
15230.92.0.0/1430.92.0.1 to 30.95.255.25430.95.255.255262,142
15330.96.0.0/1430.96.0.1 to 30.99.255.25430.99.255.255262,142
15430.100.0.0/1430.100.0.1 to 30.103.255.25430.103.255.255262,142
15530.104.0.0/1430.104.0.1 to 30.107.255.25430.107.255.255262,142
15630.108.0.0/1430.108.0.1 to 30.111.255.25430.111.255.255262,142
15730.112.0.0/1430.112.0.1 to 30.115.255.25430.115.255.255262,142
15830.116.0.0/1430.116.0.1 to 30.119.255.25430.119.255.255262,142
15930.120.0.0/1430.120.0.1 to 30.123.255.25430.123.255.255262,142
16030.124.0.0/1430.124.0.1 to 30.127.255.25430.127.255.255262,142
16130.128.0.0/1430.128.0.1 to 30.131.255.25430.131.255.255262,142
16230.132.0.0/1430.132.0.1 to 30.135.255.25430.135.255.255262,142
16330.136.0.0/1430.136.0.1 to 30.139.255.25430.139.255.255262,142
16430.140.0.0/1430.140.0.1 to 30.143.255.25430.143.255.255262,142
16530.144.0.0/1430.144.0.1 to 30.147.255.25430.147.255.255262,142
16630.148.0.0/1430.148.0.1 to 30.151.255.25430.151.255.255262,142
16730.152.0.0/1430.152.0.1 to 30.155.255.25430.155.255.255262,142
16830.156.0.0/1430.156.0.1 to 30.159.255.25430.159.255.255262,142
16930.160.0.0/1430.160.0.1 to 30.163.255.25430.163.255.255262,142
17030.164.0.0/1430.164.0.1 to 30.167.255.25430.167.255.255262,142
17130.168.0.0/1430.168.0.1 to 30.171.255.25430.171.255.255262,142
17230.172.0.0/1430.172.0.1 to 30.175.255.25430.175.255.255262,142
17330.176.0.0/1430.176.0.1 to 30.179.255.25430.179.255.255262,142
17430.180.0.0/1430.180.0.1 to 30.183.255.25430.183.255.255262,142
17530.184.0.0/1430.184.0.1 to 30.187.255.25430.187.255.255262,142
17630.188.0.0/1430.188.0.1 to 30.191.255.25430.191.255.255262,142
17730.192.0.0/1430.192.0.1 to 30.195.255.25430.195.255.255262,142
17830.196.0.0/1430.196.0.1 to 30.199.255.25430.199.255.255262,142
17930.200.0.0/1430.200.0.1 to 30.203.255.25430.203.255.255262,142
18030.204.0.0/1430.204.0.1 to 30.207.255.25430.207.255.255262,142
18130.208.0.0/1430.208.0.1 to 30.211.255.25430.211.255.255262,142
18230.212.0.0/1430.212.0.1 to 30.215.255.25430.215.255.255262,142
18330.216.0.0/1430.216.0.1 to 30.219.255.25430.219.255.255262,142
18430.220.0.0/1430.220.0.1 to 30.223.255.25430.223.255.255262,142
18530.224.0.0/1430.224.0.1 to 30.227.255.25430.227.255.255262,142
18630.228.0.0/1430.228.0.1 to 30.231.255.25430.231.255.255262,142
18730.232.0.0/1430.232.0.1 to 30.235.255.25430.235.255.255262,142
18830.236.0.0/1430.236.0.1 to 30.239.255.25430.239.255.255262,142
18930.240.0.0/1430.240.0.1 to 30.243.255.25430.243.255.255262,142
19030.244.0.0/1430.244.0.1 to 30.247.255.25430.247.255.255262,142
19130.248.0.0/1430.248.0.1 to 30.251.255.25430.251.255.255262,142
19230.252.0.0/1430.252.0.1 to 30.255.255.25430.255.255.255262,142
19331.0.0.0/1431.0.0.1 to 31.3.255.25431.3.255.255262,142
19431.4.0.0/1431.4.0.1 to 31.7.255.25431.7.255.255262,142
19531.8.0.0/1431.8.0.1 to 31.11.255.25431.11.255.255262,142
19631.12.0.0/1431.12.0.1 to 31.15.255.25431.15.255.255262,142
19731.16.0.0/1431.16.0.1 to 31.19.255.25431.19.255.255262,142
19831.20.0.0/1431.20.0.1 to 31.23.255.25431.23.255.255262,142
19931.24.0.0/1431.24.0.1 to 31.27.255.25431.27.255.255262,142
20031.28.0.0/1431.28.0.1 to 31.31.255.25431.31.255.255262,142
20131.32.0.0/1431.32.0.1 to 31.35.255.25431.35.255.255262,142
20231.36.0.0/1431.36.0.1 to 31.39.255.25431.39.255.255262,142
20331.40.0.0/1431.40.0.1 to 31.43.255.25431.43.255.255262,142
20431.44.0.0/1431.44.0.1 to 31.47.255.25431.47.255.255262,142
20531.48.0.0/1431.48.0.1 to 31.51.255.25431.51.255.255262,142
20631.52.0.0/1431.52.0.1 to 31.55.255.25431.55.255.255262,142
20731.56.0.0/1431.56.0.1 to 31.59.255.25431.59.255.255262,142
20831.60.0.0/1431.60.0.1 to 31.63.255.25431.63.255.255262,142
20931.64.0.0/1431.64.0.1 to 31.67.255.25431.67.255.255262,142
21031.68.0.0/1431.68.0.1 to 31.71.255.25431.71.255.255262,142
21131.72.0.0/1431.72.0.1 to 31.75.255.25431.75.255.255262,142
21231.76.0.0/1431.76.0.1 to 31.79.255.25431.79.255.255262,142
21331.80.0.0/1431.80.0.1 to 31.83.255.25431.83.255.255262,142
21431.84.0.0/1431.84.0.1 to 31.87.255.25431.87.255.255262,142
21531.88.0.0/1431.88.0.1 to 31.91.255.25431.91.255.255262,142
21631.92.0.0/1431.92.0.1 to 31.95.255.25431.95.255.255262,142
21731.96.0.0/1431.96.0.1 to 31.99.255.25431.99.255.255262,142
21831.100.0.0/1431.100.0.1 to 31.103.255.25431.103.255.255262,142
21931.104.0.0/1431.104.0.1 to 31.107.255.25431.107.255.255262,142
22031.108.0.0/1431.108.0.1 to 31.111.255.25431.111.255.255262,142
22131.112.0.0/1431.112.0.1 to 31.115.255.25431.115.255.255262,142
22231.116.0.0/1431.116.0.1 to 31.119.255.25431.119.255.255262,142
22331.120.0.0/1431.120.0.1 to 31.123.255.25431.123.255.255262,142
22431.124.0.0/1431.124.0.1 to 31.127.255.25431.127.255.255262,142
22531.128.0.0/1431.128.0.1 to 31.131.255.25431.131.255.255262,142
22631.132.0.0/1431.132.0.1 to 31.135.255.25431.135.255.255262,142
22731.136.0.0/1431.136.0.1 to 31.139.255.25431.139.255.255262,142
22831.140.0.0/1431.140.0.1 to 31.143.255.25431.143.255.255262,142
22931.144.0.0/1431.144.0.1 to 31.147.255.25431.147.255.255262,142
23031.148.0.0/1431.148.0.1 to 31.151.255.25431.151.255.255262,142
23131.152.0.0/1431.152.0.1 to 31.155.255.25431.155.255.255262,142
23231.156.0.0/1431.156.0.1 to 31.159.255.25431.159.255.255262,142
23331.160.0.0/1431.160.0.1 to 31.163.255.25431.163.255.255262,142
23431.164.0.0/1431.164.0.1 to 31.167.255.25431.167.255.255262,142
23531.168.0.0/1431.168.0.1 to 31.171.255.25431.171.255.255262,142
23631.172.0.0/1431.172.0.1 to 31.175.255.25431.175.255.255262,142
23731.176.0.0/1431.176.0.1 to 31.179.255.25431.179.255.255262,142
23831.180.0.0/1431.180.0.1 to 31.183.255.25431.183.255.255262,142
23931.184.0.0/1431.184.0.1 to 31.187.255.25431.187.255.255262,142
24031.188.0.0/1431.188.0.1 to 31.191.255.25431.191.255.255262,142
24131.192.0.0/1431.192.0.1 to 31.195.255.25431.195.255.255262,142
24231.196.0.0/1431.196.0.1 to 31.199.255.25431.199.255.255262,142
24331.200.0.0/1431.200.0.1 to 31.203.255.25431.203.255.255262,142
24431.204.0.0/1431.204.0.1 to 31.207.255.25431.207.255.255262,142
24531.208.0.0/1431.208.0.1 to 31.211.255.25431.211.255.255262,142
24631.212.0.0/1431.212.0.1 to 31.215.255.25431.215.255.255262,142
24731.216.0.0/1431.216.0.1 to 31.219.255.25431.219.255.255262,142
24831.220.0.0/1431.220.0.1 to 31.223.255.25431.223.255.255262,142
24931.224.0.0/1431.224.0.1 to 31.227.255.25431.227.255.255262,142
25031.228.0.0/1431.228.0.1 to 31.231.255.25431.231.255.255262,142
25131.232.0.0/1431.232.0.1 to 31.235.255.25431.235.255.255262,142
25231.236.0.0/1431.236.0.1 to 31.239.255.25431.239.255.255262,142
25331.240.0.0/1431.240.0.1 to 31.243.255.25431.243.255.255262,142
25431.244.0.0/1431.244.0.1 to 31.247.255.25431.247.255.255262,142
25531.248.0.0/1431.248.0.1 to 31.251.255.25431.251.255.255262,142
25631.252.0.0/1431.252.0.1 to 31.255.255.25431.255.255.255262,142

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.