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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.

Network48.128.0.0/10
Usable hosts4,194,302
Subnet mask255.192.0.0
Addresses4,194,304
Network address
48.128.0.0
Broadcast address
48.191.255.255
First usable
48.128.0.1
Last usable
48.191.255.254
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 30800000 · Integer 813694976 to 817889279
Reverse DNS zones
128.48.in-addr.arpa
129.48.in-addr.arpa
130.48.in-addr.arpa
131.48.in-addr.arpa
132.48.in-addr.arpa
133.48.in-addr.arpa
134.48.in-addr.arpa
135.48.in-addr.arpa
136.48.in-addr.arpa
137.48.in-addr.arpa
138.48.in-addr.arpa
139.48.in-addr.arpa
140.48.in-addr.arpa
141.48.in-addr.arpa
142.48.in-addr.arpa
143.48.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
Address00110000.10000000.00000000.0000000048.128.0.0
Subnet mask11111111.11000000.00000000.00000000255.192.0.0
Network00110000.10000000.00000000.0000000048.128.0.0
Broadcast00110000.10111111.11111111.1111111148.191.255.255
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)

48.128.0.0/10 makes 2,048 subnets of /21; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
148.128.0.0/2148.128.0.1 to 48.128.7.25448.128.7.2552,046
248.128.8.0/2148.128.8.1 to 48.128.15.25448.128.15.2552,046
348.128.16.0/2148.128.16.1 to 48.128.23.25448.128.23.2552,046
448.128.24.0/2148.128.24.1 to 48.128.31.25448.128.31.2552,046
548.128.32.0/2148.128.32.1 to 48.128.39.25448.128.39.2552,046
648.128.40.0/2148.128.40.1 to 48.128.47.25448.128.47.2552,046
748.128.48.0/2148.128.48.1 to 48.128.55.25448.128.55.2552,046
848.128.56.0/2148.128.56.1 to 48.128.63.25448.128.63.2552,046
948.128.64.0/2148.128.64.1 to 48.128.71.25448.128.71.2552,046
1048.128.72.0/2148.128.72.1 to 48.128.79.25448.128.79.2552,046
1148.128.80.0/2148.128.80.1 to 48.128.87.25448.128.87.2552,046
1248.128.88.0/2148.128.88.1 to 48.128.95.25448.128.95.2552,046
1348.128.96.0/2148.128.96.1 to 48.128.103.25448.128.103.2552,046
1448.128.104.0/2148.128.104.1 to 48.128.111.25448.128.111.2552,046
1548.128.112.0/2148.128.112.1 to 48.128.119.25448.128.119.2552,046
1648.128.120.0/2148.128.120.1 to 48.128.127.25448.128.127.2552,046
1748.128.128.0/2148.128.128.1 to 48.128.135.25448.128.135.2552,046
1848.128.136.0/2148.128.136.1 to 48.128.143.25448.128.143.2552,046
1948.128.144.0/2148.128.144.1 to 48.128.151.25448.128.151.2552,046
2048.128.152.0/2148.128.152.1 to 48.128.159.25448.128.159.2552,046
2148.128.160.0/2148.128.160.1 to 48.128.167.25448.128.167.2552,046
2248.128.168.0/2148.128.168.1 to 48.128.175.25448.128.175.2552,046
2348.128.176.0/2148.128.176.1 to 48.128.183.25448.128.183.2552,046
2448.128.184.0/2148.128.184.1 to 48.128.191.25448.128.191.2552,046
2548.128.192.0/2148.128.192.1 to 48.128.199.25448.128.199.2552,046
2648.128.200.0/2148.128.200.1 to 48.128.207.25448.128.207.2552,046
2748.128.208.0/2148.128.208.1 to 48.128.215.25448.128.215.2552,046
2848.128.216.0/2148.128.216.1 to 48.128.223.25448.128.223.2552,046
2948.128.224.0/2148.128.224.1 to 48.128.231.25448.128.231.2552,046
3048.128.232.0/2148.128.232.1 to 48.128.239.25448.128.239.2552,046
3148.128.240.0/2148.128.240.1 to 48.128.247.25448.128.247.2552,046
3248.128.248.0/2148.128.248.1 to 48.128.255.25448.128.255.2552,046
3348.129.0.0/2148.129.0.1 to 48.129.7.25448.129.7.2552,046
3448.129.8.0/2148.129.8.1 to 48.129.15.25448.129.15.2552,046
3548.129.16.0/2148.129.16.1 to 48.129.23.25448.129.23.2552,046
3648.129.24.0/2148.129.24.1 to 48.129.31.25448.129.31.2552,046
3748.129.32.0/2148.129.32.1 to 48.129.39.25448.129.39.2552,046
3848.129.40.0/2148.129.40.1 to 48.129.47.25448.129.47.2552,046
3948.129.48.0/2148.129.48.1 to 48.129.55.25448.129.55.2552,046
4048.129.56.0/2148.129.56.1 to 48.129.63.25448.129.63.2552,046
4148.129.64.0/2148.129.64.1 to 48.129.71.25448.129.71.2552,046
4248.129.72.0/2148.129.72.1 to 48.129.79.25448.129.79.2552,046
4348.129.80.0/2148.129.80.1 to 48.129.87.25448.129.87.2552,046
4448.129.88.0/2148.129.88.1 to 48.129.95.25448.129.95.2552,046
4548.129.96.0/2148.129.96.1 to 48.129.103.25448.129.103.2552,046
4648.129.104.0/2148.129.104.1 to 48.129.111.25448.129.111.2552,046
4748.129.112.0/2148.129.112.1 to 48.129.119.25448.129.119.2552,046
4848.129.120.0/2148.129.120.1 to 48.129.127.25448.129.127.2552,046
4948.129.128.0/2148.129.128.1 to 48.129.135.25448.129.135.2552,046
5048.129.136.0/2148.129.136.1 to 48.129.143.25448.129.143.2552,046
5148.129.144.0/2148.129.144.1 to 48.129.151.25448.129.151.2552,046
5248.129.152.0/2148.129.152.1 to 48.129.159.25448.129.159.2552,046
5348.129.160.0/2148.129.160.1 to 48.129.167.25448.129.167.2552,046
5448.129.168.0/2148.129.168.1 to 48.129.175.25448.129.175.2552,046
5548.129.176.0/2148.129.176.1 to 48.129.183.25448.129.183.2552,046
5648.129.184.0/2148.129.184.1 to 48.129.191.25448.129.191.2552,046
5748.129.192.0/2148.129.192.1 to 48.129.199.25448.129.199.2552,046
5848.129.200.0/2148.129.200.1 to 48.129.207.25448.129.207.2552,046
5948.129.208.0/2148.129.208.1 to 48.129.215.25448.129.215.2552,046
6048.129.216.0/2148.129.216.1 to 48.129.223.25448.129.223.2552,046
6148.129.224.0/2148.129.224.1 to 48.129.231.25448.129.231.2552,046
6248.129.232.0/2148.129.232.1 to 48.129.239.25448.129.239.2552,046
6348.129.240.0/2148.129.240.1 to 48.129.247.25448.129.247.2552,046
6448.129.248.0/2148.129.248.1 to 48.129.255.25448.129.255.2552,046
6548.130.0.0/2148.130.0.1 to 48.130.7.25448.130.7.2552,046
6648.130.8.0/2148.130.8.1 to 48.130.15.25448.130.15.2552,046
6748.130.16.0/2148.130.16.1 to 48.130.23.25448.130.23.2552,046
6848.130.24.0/2148.130.24.1 to 48.130.31.25448.130.31.2552,046
6948.130.32.0/2148.130.32.1 to 48.130.39.25448.130.39.2552,046
7048.130.40.0/2148.130.40.1 to 48.130.47.25448.130.47.2552,046
7148.130.48.0/2148.130.48.1 to 48.130.55.25448.130.55.2552,046
7248.130.56.0/2148.130.56.1 to 48.130.63.25448.130.63.2552,046
7348.130.64.0/2148.130.64.1 to 48.130.71.25448.130.71.2552,046
7448.130.72.0/2148.130.72.1 to 48.130.79.25448.130.79.2552,046
7548.130.80.0/2148.130.80.1 to 48.130.87.25448.130.87.2552,046
7648.130.88.0/2148.130.88.1 to 48.130.95.25448.130.95.2552,046
7748.130.96.0/2148.130.96.1 to 48.130.103.25448.130.103.2552,046
7848.130.104.0/2148.130.104.1 to 48.130.111.25448.130.111.2552,046
7948.130.112.0/2148.130.112.1 to 48.130.119.25448.130.119.2552,046
8048.130.120.0/2148.130.120.1 to 48.130.127.25448.130.127.2552,046
8148.130.128.0/2148.130.128.1 to 48.130.135.25448.130.135.2552,046
8248.130.136.0/2148.130.136.1 to 48.130.143.25448.130.143.2552,046
8348.130.144.0/2148.130.144.1 to 48.130.151.25448.130.151.2552,046
8448.130.152.0/2148.130.152.1 to 48.130.159.25448.130.159.2552,046
8548.130.160.0/2148.130.160.1 to 48.130.167.25448.130.167.2552,046
8648.130.168.0/2148.130.168.1 to 48.130.175.25448.130.175.2552,046
8748.130.176.0/2148.130.176.1 to 48.130.183.25448.130.183.2552,046
8848.130.184.0/2148.130.184.1 to 48.130.191.25448.130.191.2552,046
8948.130.192.0/2148.130.192.1 to 48.130.199.25448.130.199.2552,046
9048.130.200.0/2148.130.200.1 to 48.130.207.25448.130.207.2552,046
9148.130.208.0/2148.130.208.1 to 48.130.215.25448.130.215.2552,046
9248.130.216.0/2148.130.216.1 to 48.130.223.25448.130.223.2552,046
9348.130.224.0/2148.130.224.1 to 48.130.231.25448.130.231.2552,046
9448.130.232.0/2148.130.232.1 to 48.130.239.25448.130.239.2552,046
9548.130.240.0/2148.130.240.1 to 48.130.247.25448.130.247.2552,046
9648.130.248.0/2148.130.248.1 to 48.130.255.25448.130.255.2552,046
9748.131.0.0/2148.131.0.1 to 48.131.7.25448.131.7.2552,046
9848.131.8.0/2148.131.8.1 to 48.131.15.25448.131.15.2552,046
9948.131.16.0/2148.131.16.1 to 48.131.23.25448.131.23.2552,046
10048.131.24.0/2148.131.24.1 to 48.131.31.25448.131.31.2552,046
10148.131.32.0/2148.131.32.1 to 48.131.39.25448.131.39.2552,046
10248.131.40.0/2148.131.40.1 to 48.131.47.25448.131.47.2552,046
10348.131.48.0/2148.131.48.1 to 48.131.55.25448.131.55.2552,046
10448.131.56.0/2148.131.56.1 to 48.131.63.25448.131.63.2552,046
10548.131.64.0/2148.131.64.1 to 48.131.71.25448.131.71.2552,046
10648.131.72.0/2148.131.72.1 to 48.131.79.25448.131.79.2552,046
10748.131.80.0/2148.131.80.1 to 48.131.87.25448.131.87.2552,046
10848.131.88.0/2148.131.88.1 to 48.131.95.25448.131.95.2552,046
10948.131.96.0/2148.131.96.1 to 48.131.103.25448.131.103.2552,046
11048.131.104.0/2148.131.104.1 to 48.131.111.25448.131.111.2552,046
11148.131.112.0/2148.131.112.1 to 48.131.119.25448.131.119.2552,046
11248.131.120.0/2148.131.120.1 to 48.131.127.25448.131.127.2552,046
11348.131.128.0/2148.131.128.1 to 48.131.135.25448.131.135.2552,046
11448.131.136.0/2148.131.136.1 to 48.131.143.25448.131.143.2552,046
11548.131.144.0/2148.131.144.1 to 48.131.151.25448.131.151.2552,046
11648.131.152.0/2148.131.152.1 to 48.131.159.25448.131.159.2552,046
11748.131.160.0/2148.131.160.1 to 48.131.167.25448.131.167.2552,046
11848.131.168.0/2148.131.168.1 to 48.131.175.25448.131.175.2552,046
11948.131.176.0/2148.131.176.1 to 48.131.183.25448.131.183.2552,046
12048.131.184.0/2148.131.184.1 to 48.131.191.25448.131.191.2552,046
12148.131.192.0/2148.131.192.1 to 48.131.199.25448.131.199.2552,046
12248.131.200.0/2148.131.200.1 to 48.131.207.25448.131.207.2552,046
12348.131.208.0/2148.131.208.1 to 48.131.215.25448.131.215.2552,046
12448.131.216.0/2148.131.216.1 to 48.131.223.25448.131.223.2552,046
12548.131.224.0/2148.131.224.1 to 48.131.231.25448.131.231.2552,046
12648.131.232.0/2148.131.232.1 to 48.131.239.25448.131.239.2552,046
12748.131.240.0/2148.131.240.1 to 48.131.247.25448.131.247.2552,046
12848.131.248.0/2148.131.248.1 to 48.131.255.25448.131.255.2552,046
12948.132.0.0/2148.132.0.1 to 48.132.7.25448.132.7.2552,046
13048.132.8.0/2148.132.8.1 to 48.132.15.25448.132.15.2552,046
13148.132.16.0/2148.132.16.1 to 48.132.23.25448.132.23.2552,046
13248.132.24.0/2148.132.24.1 to 48.132.31.25448.132.31.2552,046
13348.132.32.0/2148.132.32.1 to 48.132.39.25448.132.39.2552,046
13448.132.40.0/2148.132.40.1 to 48.132.47.25448.132.47.2552,046
13548.132.48.0/2148.132.48.1 to 48.132.55.25448.132.55.2552,046
13648.132.56.0/2148.132.56.1 to 48.132.63.25448.132.63.2552,046
13748.132.64.0/2148.132.64.1 to 48.132.71.25448.132.71.2552,046
13848.132.72.0/2148.132.72.1 to 48.132.79.25448.132.79.2552,046
13948.132.80.0/2148.132.80.1 to 48.132.87.25448.132.87.2552,046
14048.132.88.0/2148.132.88.1 to 48.132.95.25448.132.95.2552,046
14148.132.96.0/2148.132.96.1 to 48.132.103.25448.132.103.2552,046
14248.132.104.0/2148.132.104.1 to 48.132.111.25448.132.111.2552,046
14348.132.112.0/2148.132.112.1 to 48.132.119.25448.132.119.2552,046
14448.132.120.0/2148.132.120.1 to 48.132.127.25448.132.127.2552,046
14548.132.128.0/2148.132.128.1 to 48.132.135.25448.132.135.2552,046
14648.132.136.0/2148.132.136.1 to 48.132.143.25448.132.143.2552,046
14748.132.144.0/2148.132.144.1 to 48.132.151.25448.132.151.2552,046
14848.132.152.0/2148.132.152.1 to 48.132.159.25448.132.159.2552,046
14948.132.160.0/2148.132.160.1 to 48.132.167.25448.132.167.2552,046
15048.132.168.0/2148.132.168.1 to 48.132.175.25448.132.175.2552,046
15148.132.176.0/2148.132.176.1 to 48.132.183.25448.132.183.2552,046
15248.132.184.0/2148.132.184.1 to 48.132.191.25448.132.191.2552,046
15348.132.192.0/2148.132.192.1 to 48.132.199.25448.132.199.2552,046
15448.132.200.0/2148.132.200.1 to 48.132.207.25448.132.207.2552,046
15548.132.208.0/2148.132.208.1 to 48.132.215.25448.132.215.2552,046
15648.132.216.0/2148.132.216.1 to 48.132.223.25448.132.223.2552,046
15748.132.224.0/2148.132.224.1 to 48.132.231.25448.132.231.2552,046
15848.132.232.0/2148.132.232.1 to 48.132.239.25448.132.239.2552,046
15948.132.240.0/2148.132.240.1 to 48.132.247.25448.132.247.2552,046
16048.132.248.0/2148.132.248.1 to 48.132.255.25448.132.255.2552,046
16148.133.0.0/2148.133.0.1 to 48.133.7.25448.133.7.2552,046
16248.133.8.0/2148.133.8.1 to 48.133.15.25448.133.15.2552,046
16348.133.16.0/2148.133.16.1 to 48.133.23.25448.133.23.2552,046
16448.133.24.0/2148.133.24.1 to 48.133.31.25448.133.31.2552,046
16548.133.32.0/2148.133.32.1 to 48.133.39.25448.133.39.2552,046
16648.133.40.0/2148.133.40.1 to 48.133.47.25448.133.47.2552,046
16748.133.48.0/2148.133.48.1 to 48.133.55.25448.133.55.2552,046
16848.133.56.0/2148.133.56.1 to 48.133.63.25448.133.63.2552,046
16948.133.64.0/2148.133.64.1 to 48.133.71.25448.133.71.2552,046
17048.133.72.0/2148.133.72.1 to 48.133.79.25448.133.79.2552,046
17148.133.80.0/2148.133.80.1 to 48.133.87.25448.133.87.2552,046
17248.133.88.0/2148.133.88.1 to 48.133.95.25448.133.95.2552,046
17348.133.96.0/2148.133.96.1 to 48.133.103.25448.133.103.2552,046
17448.133.104.0/2148.133.104.1 to 48.133.111.25448.133.111.2552,046
17548.133.112.0/2148.133.112.1 to 48.133.119.25448.133.119.2552,046
17648.133.120.0/2148.133.120.1 to 48.133.127.25448.133.127.2552,046
17748.133.128.0/2148.133.128.1 to 48.133.135.25448.133.135.2552,046
17848.133.136.0/2148.133.136.1 to 48.133.143.25448.133.143.2552,046
17948.133.144.0/2148.133.144.1 to 48.133.151.25448.133.151.2552,046
18048.133.152.0/2148.133.152.1 to 48.133.159.25448.133.159.2552,046
18148.133.160.0/2148.133.160.1 to 48.133.167.25448.133.167.2552,046
18248.133.168.0/2148.133.168.1 to 48.133.175.25448.133.175.2552,046
18348.133.176.0/2148.133.176.1 to 48.133.183.25448.133.183.2552,046
18448.133.184.0/2148.133.184.1 to 48.133.191.25448.133.191.2552,046
18548.133.192.0/2148.133.192.1 to 48.133.199.25448.133.199.2552,046
18648.133.200.0/2148.133.200.1 to 48.133.207.25448.133.207.2552,046
18748.133.208.0/2148.133.208.1 to 48.133.215.25448.133.215.2552,046
18848.133.216.0/2148.133.216.1 to 48.133.223.25448.133.223.2552,046
18948.133.224.0/2148.133.224.1 to 48.133.231.25448.133.231.2552,046
19048.133.232.0/2148.133.232.1 to 48.133.239.25448.133.239.2552,046
19148.133.240.0/2148.133.240.1 to 48.133.247.25448.133.247.2552,046
19248.133.248.0/2148.133.248.1 to 48.133.255.25448.133.255.2552,046
19348.134.0.0/2148.134.0.1 to 48.134.7.25448.134.7.2552,046
19448.134.8.0/2148.134.8.1 to 48.134.15.25448.134.15.2552,046
19548.134.16.0/2148.134.16.1 to 48.134.23.25448.134.23.2552,046
19648.134.24.0/2148.134.24.1 to 48.134.31.25448.134.31.2552,046
19748.134.32.0/2148.134.32.1 to 48.134.39.25448.134.39.2552,046
19848.134.40.0/2148.134.40.1 to 48.134.47.25448.134.47.2552,046
19948.134.48.0/2148.134.48.1 to 48.134.55.25448.134.55.2552,046
20048.134.56.0/2148.134.56.1 to 48.134.63.25448.134.63.2552,046
20148.134.64.0/2148.134.64.1 to 48.134.71.25448.134.71.2552,046
20248.134.72.0/2148.134.72.1 to 48.134.79.25448.134.79.2552,046
20348.134.80.0/2148.134.80.1 to 48.134.87.25448.134.87.2552,046
20448.134.88.0/2148.134.88.1 to 48.134.95.25448.134.95.2552,046
20548.134.96.0/2148.134.96.1 to 48.134.103.25448.134.103.2552,046
20648.134.104.0/2148.134.104.1 to 48.134.111.25448.134.111.2552,046
20748.134.112.0/2148.134.112.1 to 48.134.119.25448.134.119.2552,046
20848.134.120.0/2148.134.120.1 to 48.134.127.25448.134.127.2552,046
20948.134.128.0/2148.134.128.1 to 48.134.135.25448.134.135.2552,046
21048.134.136.0/2148.134.136.1 to 48.134.143.25448.134.143.2552,046
21148.134.144.0/2148.134.144.1 to 48.134.151.25448.134.151.2552,046
21248.134.152.0/2148.134.152.1 to 48.134.159.25448.134.159.2552,046
21348.134.160.0/2148.134.160.1 to 48.134.167.25448.134.167.2552,046
21448.134.168.0/2148.134.168.1 to 48.134.175.25448.134.175.2552,046
21548.134.176.0/2148.134.176.1 to 48.134.183.25448.134.183.2552,046
21648.134.184.0/2148.134.184.1 to 48.134.191.25448.134.191.2552,046
21748.134.192.0/2148.134.192.1 to 48.134.199.25448.134.199.2552,046
21848.134.200.0/2148.134.200.1 to 48.134.207.25448.134.207.2552,046
21948.134.208.0/2148.134.208.1 to 48.134.215.25448.134.215.2552,046
22048.134.216.0/2148.134.216.1 to 48.134.223.25448.134.223.2552,046
22148.134.224.0/2148.134.224.1 to 48.134.231.25448.134.231.2552,046
22248.134.232.0/2148.134.232.1 to 48.134.239.25448.134.239.2552,046
22348.134.240.0/2148.134.240.1 to 48.134.247.25448.134.247.2552,046
22448.134.248.0/2148.134.248.1 to 48.134.255.25448.134.255.2552,046
22548.135.0.0/2148.135.0.1 to 48.135.7.25448.135.7.2552,046
22648.135.8.0/2148.135.8.1 to 48.135.15.25448.135.15.2552,046
22748.135.16.0/2148.135.16.1 to 48.135.23.25448.135.23.2552,046
22848.135.24.0/2148.135.24.1 to 48.135.31.25448.135.31.2552,046
22948.135.32.0/2148.135.32.1 to 48.135.39.25448.135.39.2552,046
23048.135.40.0/2148.135.40.1 to 48.135.47.25448.135.47.2552,046
23148.135.48.0/2148.135.48.1 to 48.135.55.25448.135.55.2552,046
23248.135.56.0/2148.135.56.1 to 48.135.63.25448.135.63.2552,046
23348.135.64.0/2148.135.64.1 to 48.135.71.25448.135.71.2552,046
23448.135.72.0/2148.135.72.1 to 48.135.79.25448.135.79.2552,046
23548.135.80.0/2148.135.80.1 to 48.135.87.25448.135.87.2552,046
23648.135.88.0/2148.135.88.1 to 48.135.95.25448.135.95.2552,046
23748.135.96.0/2148.135.96.1 to 48.135.103.25448.135.103.2552,046
23848.135.104.0/2148.135.104.1 to 48.135.111.25448.135.111.2552,046
23948.135.112.0/2148.135.112.1 to 48.135.119.25448.135.119.2552,046
24048.135.120.0/2148.135.120.1 to 48.135.127.25448.135.127.2552,046
24148.135.128.0/2148.135.128.1 to 48.135.135.25448.135.135.2552,046
24248.135.136.0/2148.135.136.1 to 48.135.143.25448.135.143.2552,046
24348.135.144.0/2148.135.144.1 to 48.135.151.25448.135.151.2552,046
24448.135.152.0/2148.135.152.1 to 48.135.159.25448.135.159.2552,046
24548.135.160.0/2148.135.160.1 to 48.135.167.25448.135.167.2552,046
24648.135.168.0/2148.135.168.1 to 48.135.175.25448.135.175.2552,046
24748.135.176.0/2148.135.176.1 to 48.135.183.25448.135.183.2552,046
24848.135.184.0/2148.135.184.1 to 48.135.191.25448.135.191.2552,046
24948.135.192.0/2148.135.192.1 to 48.135.199.25448.135.199.2552,046
25048.135.200.0/2148.135.200.1 to 48.135.207.25448.135.207.2552,046
25148.135.208.0/2148.135.208.1 to 48.135.215.25448.135.215.2552,046
25248.135.216.0/2148.135.216.1 to 48.135.223.25448.135.223.2552,046
25348.135.224.0/2148.135.224.1 to 48.135.231.25448.135.231.2552,046
25448.135.232.0/2148.135.232.1 to 48.135.239.25448.135.239.2552,046
25548.135.240.0/2148.135.240.1 to 48.135.247.25448.135.247.2552,046
25648.135.248.0/2148.135.248.1 to 48.135.255.25448.135.255.2552,046

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.