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)10.19.128.0/18
network10.19.128.0/18
broadcast10.19.191.255
first host10.19.128.1
last host10.19.191.254
subnet mask255.255.192.0
wildcard0.0.63.255
addresses16,384
usable hosts16,382
classA
ipcalc 10.19.128.0/18
address00001010.00010011.10000000.00000000
subnet mask11111111.11111111.11000000.00000000
network00001010.00010011.10000000.00000000
broadcast00001010.00010011.10111111.11111111
green = network part, grey = host part
hex0x0a138000
decimal169050112
reverse dns0.128.19.10.in-addr.arpa
ipv4-mapped::ffff:a13:8000
/18 split into /23 · 32 subnets
close ×| # | network | host range | broadcast |
|---|---|---|---|
| 1 | 10.19.128.0/23 | 10.19.128.1 – 10.19.129.254 | 10.19.129.255 |
| 2 | 10.19.130.0/23 | 10.19.130.1 – 10.19.131.254 | 10.19.131.255 |
| 3 | 10.19.132.0/23 | 10.19.132.1 – 10.19.133.254 | 10.19.133.255 |
| 4 | 10.19.134.0/23 | 10.19.134.1 – 10.19.135.254 | 10.19.135.255 |
| 5 | 10.19.136.0/23 | 10.19.136.1 – 10.19.137.254 | 10.19.137.255 |
| 6 | 10.19.138.0/23 | 10.19.138.1 – 10.19.139.254 | 10.19.139.255 |
| 7 | 10.19.140.0/23 | 10.19.140.1 – 10.19.141.254 | 10.19.141.255 |
| 8 | 10.19.142.0/23 | 10.19.142.1 – 10.19.143.254 | 10.19.143.255 |
| 9 | 10.19.144.0/23 | 10.19.144.1 – 10.19.145.254 | 10.19.145.255 |
| 10 | 10.19.146.0/23 | 10.19.146.1 – 10.19.147.254 | 10.19.147.255 |
| 11 | 10.19.148.0/23 | 10.19.148.1 – 10.19.149.254 | 10.19.149.255 |
| 12 | 10.19.150.0/23 | 10.19.150.1 – 10.19.151.254 | 10.19.151.255 |
| 13 | 10.19.152.0/23 | 10.19.152.1 – 10.19.153.254 | 10.19.153.255 |
| 14 | 10.19.154.0/23 | 10.19.154.1 – 10.19.155.254 | 10.19.155.255 |
| 15 | 10.19.156.0/23 | 10.19.156.1 – 10.19.157.254 | 10.19.157.255 |
| 16 | 10.19.158.0/23 | 10.19.158.1 – 10.19.159.254 | 10.19.159.255 |
| 17 | 10.19.160.0/23 | 10.19.160.1 – 10.19.161.254 | 10.19.161.255 |
| 18 | 10.19.162.0/23 | 10.19.162.1 – 10.19.163.254 | 10.19.163.255 |
| 19 | 10.19.164.0/23 | 10.19.164.1 – 10.19.165.254 | 10.19.165.255 |
| 20 | 10.19.166.0/23 | 10.19.166.1 – 10.19.167.254 | 10.19.167.255 |
| 21 | 10.19.168.0/23 | 10.19.168.1 – 10.19.169.254 | 10.19.169.255 |
| 22 | 10.19.170.0/23 | 10.19.170.1 – 10.19.171.254 | 10.19.171.255 |
| 23 | 10.19.172.0/23 | 10.19.172.1 – 10.19.173.254 | 10.19.173.255 |
| 24 | 10.19.174.0/23 | 10.19.174.1 – 10.19.175.254 | 10.19.175.255 |
| 25 | 10.19.176.0/23 | 10.19.176.1 – 10.19.177.254 | 10.19.177.255 |
| 26 | 10.19.178.0/23 | 10.19.178.1 – 10.19.179.254 | 10.19.179.255 |
| 27 | 10.19.180.0/23 | 10.19.180.1 – 10.19.181.254 | 10.19.181.255 |
| 28 | 10.19.182.0/23 | 10.19.182.1 – 10.19.183.254 | 10.19.183.255 |
| 29 | 10.19.184.0/23 | 10.19.184.1 – 10.19.185.254 | 10.19.185.255 |
| 30 | 10.19.186.0/23 | 10.19.186.1 – 10.19.187.254 | 10.19.187.255 |
| 31 | 10.19.188.0/23 | 10.19.188.1 – 10.19.189.254 | 10.19.189.255 |
| 32 | 10.19.190.0/23 | 10.19.190.1 – 10.19.191.254 | 10.19.191.255 |
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.