IPv4 Subnet Calculator
Enter an IP with a CIDR prefix or a subnet mask to see its network, broadcast, host range, and host count. You can also split the network into smaller subnets.
private IP (RFC 1918)10.12.128.0/18
network10.12.128.0/18
broadcast10.12.191.255
first host10.12.128.1
last host10.12.191.254
subnet mask255.255.192.0
wildcard0.0.63.255
addresses16,384
usable hosts16,382
classA
ipcalc 10.12.128.0/18
address00001010.00001100.10000000.00000000
subnet mask11111111.11111111.11000000.00000000
network00001010.00001100.10000000.00000000
broadcast00001010.00001100.10111111.11111111
green = network part, grey = host part
hex0x0a0c8000
decimal168591360
reverse dns0.128.12.10.in-addr.arpa
ipv4-mapped::ffff:a0c:8000
/18 split into /25 · 128 subnets
close ×| # | network | host range | broadcast |
|---|---|---|---|
| 1 | 10.12.128.0/25 | 10.12.128.1 – 10.12.128.126 | 10.12.128.127 |
| 2 | 10.12.128.128/25 | 10.12.128.129 – 10.12.128.254 | 10.12.128.255 |
| 3 | 10.12.129.0/25 | 10.12.129.1 – 10.12.129.126 | 10.12.129.127 |
| 4 | 10.12.129.128/25 | 10.12.129.129 – 10.12.129.254 | 10.12.129.255 |
| 5 | 10.12.130.0/25 | 10.12.130.1 – 10.12.130.126 | 10.12.130.127 |
| 6 | 10.12.130.128/25 | 10.12.130.129 – 10.12.130.254 | 10.12.130.255 |
| 7 | 10.12.131.0/25 | 10.12.131.1 – 10.12.131.126 | 10.12.131.127 |
| 8 | 10.12.131.128/25 | 10.12.131.129 – 10.12.131.254 | 10.12.131.255 |
| 9 | 10.12.132.0/25 | 10.12.132.1 – 10.12.132.126 | 10.12.132.127 |
| 10 | 10.12.132.128/25 | 10.12.132.129 – 10.12.132.254 | 10.12.132.255 |
| 11 | 10.12.133.0/25 | 10.12.133.1 – 10.12.133.126 | 10.12.133.127 |
| 12 | 10.12.133.128/25 | 10.12.133.129 – 10.12.133.254 | 10.12.133.255 |
| 13 | 10.12.134.0/25 | 10.12.134.1 – 10.12.134.126 | 10.12.134.127 |
| 14 | 10.12.134.128/25 | 10.12.134.129 – 10.12.134.254 | 10.12.134.255 |
| 15 | 10.12.135.0/25 | 10.12.135.1 – 10.12.135.126 | 10.12.135.127 |
| 16 | 10.12.135.128/25 | 10.12.135.129 – 10.12.135.254 | 10.12.135.255 |
| 17 | 10.12.136.0/25 | 10.12.136.1 – 10.12.136.126 | 10.12.136.127 |
| 18 | 10.12.136.128/25 | 10.12.136.129 – 10.12.136.254 | 10.12.136.255 |
| 19 | 10.12.137.0/25 | 10.12.137.1 – 10.12.137.126 | 10.12.137.127 |
| 20 | 10.12.137.128/25 | 10.12.137.129 – 10.12.137.254 | 10.12.137.255 |
| 21 | 10.12.138.0/25 | 10.12.138.1 – 10.12.138.126 | 10.12.138.127 |
| 22 | 10.12.138.128/25 | 10.12.138.129 – 10.12.138.254 | 10.12.138.255 |
| 23 | 10.12.139.0/25 | 10.12.139.1 – 10.12.139.126 | 10.12.139.127 |
| 24 | 10.12.139.128/25 | 10.12.139.129 – 10.12.139.254 | 10.12.139.255 |
| 25 | 10.12.140.0/25 | 10.12.140.1 – 10.12.140.126 | 10.12.140.127 |
| 26 | 10.12.140.128/25 | 10.12.140.129 – 10.12.140.254 | 10.12.140.255 |
| 27 | 10.12.141.0/25 | 10.12.141.1 – 10.12.141.126 | 10.12.141.127 |
| 28 | 10.12.141.128/25 | 10.12.141.129 – 10.12.141.254 | 10.12.141.255 |
| 29 | 10.12.142.0/25 | 10.12.142.1 – 10.12.142.126 | 10.12.142.127 |
| 30 | 10.12.142.128/25 | 10.12.142.129 – 10.12.142.254 | 10.12.142.255 |
| 31 | 10.12.143.0/25 | 10.12.143.1 – 10.12.143.126 | 10.12.143.127 |
| 32 | 10.12.143.128/25 | 10.12.143.129 – 10.12.143.254 | 10.12.143.255 |
| 33 | 10.12.144.0/25 | 10.12.144.1 – 10.12.144.126 | 10.12.144.127 |
| 34 | 10.12.144.128/25 | 10.12.144.129 – 10.12.144.254 | 10.12.144.255 |
| 35 | 10.12.145.0/25 | 10.12.145.1 – 10.12.145.126 | 10.12.145.127 |
| 36 | 10.12.145.128/25 | 10.12.145.129 – 10.12.145.254 | 10.12.145.255 |
| 37 | 10.12.146.0/25 | 10.12.146.1 – 10.12.146.126 | 10.12.146.127 |
| 38 | 10.12.146.128/25 | 10.12.146.129 – 10.12.146.254 | 10.12.146.255 |
| 39 | 10.12.147.0/25 | 10.12.147.1 – 10.12.147.126 | 10.12.147.127 |
| 40 | 10.12.147.128/25 | 10.12.147.129 – 10.12.147.254 | 10.12.147.255 |
| 41 | 10.12.148.0/25 | 10.12.148.1 – 10.12.148.126 | 10.12.148.127 |
| 42 | 10.12.148.128/25 | 10.12.148.129 – 10.12.148.254 | 10.12.148.255 |
| 43 | 10.12.149.0/25 | 10.12.149.1 – 10.12.149.126 | 10.12.149.127 |
| 44 | 10.12.149.128/25 | 10.12.149.129 – 10.12.149.254 | 10.12.149.255 |
| 45 | 10.12.150.0/25 | 10.12.150.1 – 10.12.150.126 | 10.12.150.127 |
| 46 | 10.12.150.128/25 | 10.12.150.129 – 10.12.150.254 | 10.12.150.255 |
| 47 | 10.12.151.0/25 | 10.12.151.1 – 10.12.151.126 | 10.12.151.127 |
| 48 | 10.12.151.128/25 | 10.12.151.129 – 10.12.151.254 | 10.12.151.255 |
| 49 | 10.12.152.0/25 | 10.12.152.1 – 10.12.152.126 | 10.12.152.127 |
| 50 | 10.12.152.128/25 | 10.12.152.129 – 10.12.152.254 | 10.12.152.255 |
| 51 | 10.12.153.0/25 | 10.12.153.1 – 10.12.153.126 | 10.12.153.127 |
| 52 | 10.12.153.128/25 | 10.12.153.129 – 10.12.153.254 | 10.12.153.255 |
| 53 | 10.12.154.0/25 | 10.12.154.1 – 10.12.154.126 | 10.12.154.127 |
| 54 | 10.12.154.128/25 | 10.12.154.129 – 10.12.154.254 | 10.12.154.255 |
| 55 | 10.12.155.0/25 | 10.12.155.1 – 10.12.155.126 | 10.12.155.127 |
| 56 | 10.12.155.128/25 | 10.12.155.129 – 10.12.155.254 | 10.12.155.255 |
| 57 | 10.12.156.0/25 | 10.12.156.1 – 10.12.156.126 | 10.12.156.127 |
| 58 | 10.12.156.128/25 | 10.12.156.129 – 10.12.156.254 | 10.12.156.255 |
| 59 | 10.12.157.0/25 | 10.12.157.1 – 10.12.157.126 | 10.12.157.127 |
| 60 | 10.12.157.128/25 | 10.12.157.129 – 10.12.157.254 | 10.12.157.255 |
| 61 | 10.12.158.0/25 | 10.12.158.1 – 10.12.158.126 | 10.12.158.127 |
| 62 | 10.12.158.128/25 | 10.12.158.129 – 10.12.158.254 | 10.12.158.255 |
| 63 | 10.12.159.0/25 | 10.12.159.1 – 10.12.159.126 | 10.12.159.127 |
| 64 | 10.12.159.128/25 | 10.12.159.129 – 10.12.159.254 | 10.12.159.255 |
| 65 | 10.12.160.0/25 | 10.12.160.1 – 10.12.160.126 | 10.12.160.127 |
| 66 | 10.12.160.128/25 | 10.12.160.129 – 10.12.160.254 | 10.12.160.255 |
| 67 | 10.12.161.0/25 | 10.12.161.1 – 10.12.161.126 | 10.12.161.127 |
| 68 | 10.12.161.128/25 | 10.12.161.129 – 10.12.161.254 | 10.12.161.255 |
| 69 | 10.12.162.0/25 | 10.12.162.1 – 10.12.162.126 | 10.12.162.127 |
| 70 | 10.12.162.128/25 | 10.12.162.129 – 10.12.162.254 | 10.12.162.255 |
| 71 | 10.12.163.0/25 | 10.12.163.1 – 10.12.163.126 | 10.12.163.127 |
| 72 | 10.12.163.128/25 | 10.12.163.129 – 10.12.163.254 | 10.12.163.255 |
| 73 | 10.12.164.0/25 | 10.12.164.1 – 10.12.164.126 | 10.12.164.127 |
| 74 | 10.12.164.128/25 | 10.12.164.129 – 10.12.164.254 | 10.12.164.255 |
| 75 | 10.12.165.0/25 | 10.12.165.1 – 10.12.165.126 | 10.12.165.127 |
| 76 | 10.12.165.128/25 | 10.12.165.129 – 10.12.165.254 | 10.12.165.255 |
| 77 | 10.12.166.0/25 | 10.12.166.1 – 10.12.166.126 | 10.12.166.127 |
| 78 | 10.12.166.128/25 | 10.12.166.129 – 10.12.166.254 | 10.12.166.255 |
| 79 | 10.12.167.0/25 | 10.12.167.1 – 10.12.167.126 | 10.12.167.127 |
| 80 | 10.12.167.128/25 | 10.12.167.129 – 10.12.167.254 | 10.12.167.255 |
| 81 | 10.12.168.0/25 | 10.12.168.1 – 10.12.168.126 | 10.12.168.127 |
| 82 | 10.12.168.128/25 | 10.12.168.129 – 10.12.168.254 | 10.12.168.255 |
| 83 | 10.12.169.0/25 | 10.12.169.1 – 10.12.169.126 | 10.12.169.127 |
| 84 | 10.12.169.128/25 | 10.12.169.129 – 10.12.169.254 | 10.12.169.255 |
| 85 | 10.12.170.0/25 | 10.12.170.1 – 10.12.170.126 | 10.12.170.127 |
| 86 | 10.12.170.128/25 | 10.12.170.129 – 10.12.170.254 | 10.12.170.255 |
| 87 | 10.12.171.0/25 | 10.12.171.1 – 10.12.171.126 | 10.12.171.127 |
| 88 | 10.12.171.128/25 | 10.12.171.129 – 10.12.171.254 | 10.12.171.255 |
| 89 | 10.12.172.0/25 | 10.12.172.1 – 10.12.172.126 | 10.12.172.127 |
| 90 | 10.12.172.128/25 | 10.12.172.129 – 10.12.172.254 | 10.12.172.255 |
| 91 | 10.12.173.0/25 | 10.12.173.1 – 10.12.173.126 | 10.12.173.127 |
| 92 | 10.12.173.128/25 | 10.12.173.129 – 10.12.173.254 | 10.12.173.255 |
| 93 | 10.12.174.0/25 | 10.12.174.1 – 10.12.174.126 | 10.12.174.127 |
| 94 | 10.12.174.128/25 | 10.12.174.129 – 10.12.174.254 | 10.12.174.255 |
| 95 | 10.12.175.0/25 | 10.12.175.1 – 10.12.175.126 | 10.12.175.127 |
| 96 | 10.12.175.128/25 | 10.12.175.129 – 10.12.175.254 | 10.12.175.255 |
| 97 | 10.12.176.0/25 | 10.12.176.1 – 10.12.176.126 | 10.12.176.127 |
| 98 | 10.12.176.128/25 | 10.12.176.129 – 10.12.176.254 | 10.12.176.255 |
| 99 | 10.12.177.0/25 | 10.12.177.1 – 10.12.177.126 | 10.12.177.127 |
| 100 | 10.12.177.128/25 | 10.12.177.129 – 10.12.177.254 | 10.12.177.255 |
| 101 | 10.12.178.0/25 | 10.12.178.1 – 10.12.178.126 | 10.12.178.127 |
| 102 | 10.12.178.128/25 | 10.12.178.129 – 10.12.178.254 | 10.12.178.255 |
| 103 | 10.12.179.0/25 | 10.12.179.1 – 10.12.179.126 | 10.12.179.127 |
| 104 | 10.12.179.128/25 | 10.12.179.129 – 10.12.179.254 | 10.12.179.255 |
| 105 | 10.12.180.0/25 | 10.12.180.1 – 10.12.180.126 | 10.12.180.127 |
| 106 | 10.12.180.128/25 | 10.12.180.129 – 10.12.180.254 | 10.12.180.255 |
| 107 | 10.12.181.0/25 | 10.12.181.1 – 10.12.181.126 | 10.12.181.127 |
| 108 | 10.12.181.128/25 | 10.12.181.129 – 10.12.181.254 | 10.12.181.255 |
| 109 | 10.12.182.0/25 | 10.12.182.1 – 10.12.182.126 | 10.12.182.127 |
| 110 | 10.12.182.128/25 | 10.12.182.129 – 10.12.182.254 | 10.12.182.255 |
| 111 | 10.12.183.0/25 | 10.12.183.1 – 10.12.183.126 | 10.12.183.127 |
| 112 | 10.12.183.128/25 | 10.12.183.129 – 10.12.183.254 | 10.12.183.255 |
| 113 | 10.12.184.0/25 | 10.12.184.1 – 10.12.184.126 | 10.12.184.127 |
| 114 | 10.12.184.128/25 | 10.12.184.129 – 10.12.184.254 | 10.12.184.255 |
| 115 | 10.12.185.0/25 | 10.12.185.1 – 10.12.185.126 | 10.12.185.127 |
| 116 | 10.12.185.128/25 | 10.12.185.129 – 10.12.185.254 | 10.12.185.255 |
| 117 | 10.12.186.0/25 | 10.12.186.1 – 10.12.186.126 | 10.12.186.127 |
| 118 | 10.12.186.128/25 | 10.12.186.129 – 10.12.186.254 | 10.12.186.255 |
| 119 | 10.12.187.0/25 | 10.12.187.1 – 10.12.187.126 | 10.12.187.127 |
| 120 | 10.12.187.128/25 | 10.12.187.129 – 10.12.187.254 | 10.12.187.255 |
| 121 | 10.12.188.0/25 | 10.12.188.1 – 10.12.188.126 | 10.12.188.127 |
| 122 | 10.12.188.128/25 | 10.12.188.129 – 10.12.188.254 | 10.12.188.255 |
| 123 | 10.12.189.0/25 | 10.12.189.1 – 10.12.189.126 | 10.12.189.127 |
| 124 | 10.12.189.128/25 | 10.12.189.129 – 10.12.189.254 | 10.12.189.255 |
| 125 | 10.12.190.0/25 | 10.12.190.1 – 10.12.190.126 | 10.12.190.127 |
| 126 | 10.12.190.128/25 | 10.12.190.129 – 10.12.190.254 | 10.12.190.255 |
| 127 | 10.12.191.0/25 | 10.12.191.1 – 10.12.191.126 | 10.12.191.127 |
| 128 | 10.12.191.128/25 | 10.12.191.129 – 10.12.191.254 | 10.12.191.255 |
01 / table
IPv4 CIDR prefix table.
Click a prefix longer than your network to split it into subnets.
| prefix | subnet mask | addresses | hosts | in your /18 |
|---|---|---|---|---|
| /0 | 0.0.0.0 | 4,294,967,296 | 4,294,967,294 | - |
| /1 | 128.0.0.0 | 2,147,483,648 | 2,147,483,646 | - |
| /2 | 192.0.0.0 | 1,073,741,824 | 1,073,741,822 | - |
| /3 | 224.0.0.0 | 536,870,912 | 536,870,910 | - |
| /4 | 240.0.0.0 | 268,435,456 | 268,435,454 | - |
| /5 | 248.0.0.0 | 134,217,728 | 134,217,726 | - |
| /6 | 252.0.0.0 | 67,108,864 | 67,108,862 | - |
| /7 | 254.0.0.0 | 33,554,432 | 33,554,430 | - |
| /8 | 255.0.0.0 | 16,777,216 | 16,777,214 | - |
| /9 | 255.128.0.0 | 8,388,608 | 8,388,606 | - |
| /10 | 255.192.0.0 | 4,194,304 | 4,194,302 | - |
| /11 | 255.224.0.0 | 2,097,152 | 2,097,150 | - |
| /12 | 255.240.0.0 | 1,048,576 | 1,048,574 | - |
| /13 | 255.248.0.0 | 524,288 | 524,286 | - |
| /14 | 255.252.0.0 | 262,144 | 262,142 | - |
| /15 | 255.254.0.0 | 131,072 | 131,070 | - |
| /16 | 255.255.0.0 | 65,536 | 65,534 | - |
| /17 | 255.255.128.0 | 32,768 | 32,766 | - |
| /18 | 255.255.192.0 | 16,384 | 16,382 | 1 |
| /19 | 255.255.224.0 | 8,192 | 8,190 | 2 split → |
| /20 | 255.255.240.0 | 4,096 | 4,094 | 4 split → |
| /21 | 255.255.248.0 | 2,048 | 2,046 | 8 split → |
| /22 | 255.255.252.0 | 1,024 | 1,022 | 16 split → |
| /23 | 255.255.254.0 | 512 | 510 | 32 split → |
| /24 | 255.255.255.0 | 256 | 254 | 64 split → |
| /25 | 255.255.255.128 | 128 | 126 | 128 split → |
| /26 | 255.255.255.192 | 64 | 62 | 256 split → |
| /27 | 255.255.255.224 | 32 | 30 | 512 split → |
| /28 | 255.255.255.240 | 16 | 14 | 1,024 split → |
| /29 | 255.255.255.248 | 8 | 6 | 2,048 split → |
| /30 | 255.255.255.252 | 4 | 2 | 4,096 split → |
| /31 | 255.255.255.254 | 2 | 2 | 8,192 split → |
| /32 | 255.255.255.255 | 1 | 1 | 16,384 split → |
02 / faq
About this calculator.
How do I use this subnet calculator?
▼
Type an IP address followed by a prefix, like 192.168.1.10/24, or by a subnet mask, like 192.168.1.10 255.255.255.0. Without a prefix it uses /24. Click a row in the table to split the network into smaller subnets.
Why are usable hosts always 2 fewer?
▼
The first address in a subnet is the network address and the last is the broadcast address, so neither can go to a device. The exceptions are /31 (point-to-point links, RFC 3021) and /32 (a single address), which use every address.
Can I use it from a terminal?
▼
Yes. curl 'ipku.in/en/tools/ipv4-subnet-calculator?q=192.168.1.10/24' returns the result as plain text.