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)10.4.187.0/25
network10.4.187.0/25
broadcast10.4.187.127
first host10.4.187.1
last host10.4.187.126
subnet mask255.255.255.128
wildcard0.0.0.127
addresses128
usable hosts126
classA
ipcalc 10.4.187.0/25
address00001010.00000100.10111011.00000000
subnet mask11111111.11111111.11111111.10000000
network00001010.00000100.10111011.00000000
broadcast00001010.00000100.10111011.01111111
green = network part, grey = host part
hex0x0a04bb00
decimal168082176
reverse dns0.187.4.10.in-addr.arpa
ipv4-mapped::ffff:a04:bb00
/25 split into /30 · 32 subnets
close ×| # | network | host range | broadcast |
|---|---|---|---|
| 1 | 10.4.187.0/30 | 10.4.187.1 – 10.4.187.2 | 10.4.187.3 |
| 2 | 10.4.187.4/30 | 10.4.187.5 – 10.4.187.6 | 10.4.187.7 |
| 3 | 10.4.187.8/30 | 10.4.187.9 – 10.4.187.10 | 10.4.187.11 |
| 4 | 10.4.187.12/30 | 10.4.187.13 – 10.4.187.14 | 10.4.187.15 |
| 5 | 10.4.187.16/30 | 10.4.187.17 – 10.4.187.18 | 10.4.187.19 |
| 6 | 10.4.187.20/30 | 10.4.187.21 – 10.4.187.22 | 10.4.187.23 |
| 7 | 10.4.187.24/30 | 10.4.187.25 – 10.4.187.26 | 10.4.187.27 |
| 8 | 10.4.187.28/30 | 10.4.187.29 – 10.4.187.30 | 10.4.187.31 |
| 9 | 10.4.187.32/30 | 10.4.187.33 – 10.4.187.34 | 10.4.187.35 |
| 10 | 10.4.187.36/30 | 10.4.187.37 – 10.4.187.38 | 10.4.187.39 |
| 11 | 10.4.187.40/30 | 10.4.187.41 – 10.4.187.42 | 10.4.187.43 |
| 12 | 10.4.187.44/30 | 10.4.187.45 – 10.4.187.46 | 10.4.187.47 |
| 13 | 10.4.187.48/30 | 10.4.187.49 – 10.4.187.50 | 10.4.187.51 |
| 14 | 10.4.187.52/30 | 10.4.187.53 – 10.4.187.54 | 10.4.187.55 |
| 15 | 10.4.187.56/30 | 10.4.187.57 – 10.4.187.58 | 10.4.187.59 |
| 16 | 10.4.187.60/30 | 10.4.187.61 – 10.4.187.62 | 10.4.187.63 |
| 17 | 10.4.187.64/30 | 10.4.187.65 – 10.4.187.66 | 10.4.187.67 |
| 18 | 10.4.187.68/30 | 10.4.187.69 – 10.4.187.70 | 10.4.187.71 |
| 19 | 10.4.187.72/30 | 10.4.187.73 – 10.4.187.74 | 10.4.187.75 |
| 20 | 10.4.187.76/30 | 10.4.187.77 – 10.4.187.78 | 10.4.187.79 |
| 21 | 10.4.187.80/30 | 10.4.187.81 – 10.4.187.82 | 10.4.187.83 |
| 22 | 10.4.187.84/30 | 10.4.187.85 – 10.4.187.86 | 10.4.187.87 |
| 23 | 10.4.187.88/30 | 10.4.187.89 – 10.4.187.90 | 10.4.187.91 |
| 24 | 10.4.187.92/30 | 10.4.187.93 – 10.4.187.94 | 10.4.187.95 |
| 25 | 10.4.187.96/30 | 10.4.187.97 – 10.4.187.98 | 10.4.187.99 |
| 26 | 10.4.187.100/30 | 10.4.187.101 – 10.4.187.102 | 10.4.187.103 |
| 27 | 10.4.187.104/30 | 10.4.187.105 – 10.4.187.106 | 10.4.187.107 |
| 28 | 10.4.187.108/30 | 10.4.187.109 – 10.4.187.110 | 10.4.187.111 |
| 29 | 10.4.187.112/30 | 10.4.187.113 – 10.4.187.114 | 10.4.187.115 |
| 30 | 10.4.187.116/30 | 10.4.187.117 – 10.4.187.118 | 10.4.187.119 |
| 31 | 10.4.187.120/30 | 10.4.187.121 – 10.4.187.122 | 10.4.187.123 |
| 32 | 10.4.187.124/30 | 10.4.187.125 – 10.4.187.126 | 10.4.187.127 |
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 /25 |
|---|---|---|---|---|
| /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 | - |
| /19 | 255.255.224.0 | 8,192 | 8,190 | - |
| /20 | 255.255.240.0 | 4,096 | 4,094 | - |
| /21 | 255.255.248.0 | 2,048 | 2,046 | - |
| /22 | 255.255.252.0 | 1,024 | 1,022 | - |
| /23 | 255.255.254.0 | 512 | 510 | - |
| /24 | 255.255.255.0 | 256 | 254 | - |
| /25 | 255.255.255.128 | 128 | 126 | 1 |
| /26 | 255.255.255.192 | 64 | 62 | 2 split → |
| /27 | 255.255.255.224 | 32 | 30 | 4 split → |
| /28 | 255.255.255.240 | 16 | 14 | 8 split → |
| /29 | 255.255.255.248 | 8 | 6 | 16 split → |
| /30 | 255.255.255.252 | 4 | 2 | 32 split → |
| /31 | 255.255.255.254 | 2 | 2 | 64 split → |
| /32 | 255.255.255.255 | 1 | 1 | 128 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.