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)172.16.2.0/25
network172.16.2.0/25
broadcast172.16.2.127
first host172.16.2.1
last host172.16.2.126
subnet mask255.255.255.128
wildcard0.0.0.127
addresses128
usable hosts126
classB
ipcalc 172.16.2.0/25
address10101100.00010000.00000010.00000000
subnet mask11111111.11111111.11111111.10000000
network10101100.00010000.00000010.00000000
broadcast10101100.00010000.00000010.01111111
green = network part, grey = host part
hex0xac100200
decimal2886730240
reverse dns0.2.16.172.in-addr.arpa
ipv4-mapped::ffff:ac10:200
/25 split into /30 · 32 subnets
close ×| # | network | host range | broadcast |
|---|---|---|---|
| 1 | 172.16.2.0/30 | 172.16.2.1 – 172.16.2.2 | 172.16.2.3 |
| 2 | 172.16.2.4/30 | 172.16.2.5 – 172.16.2.6 | 172.16.2.7 |
| 3 | 172.16.2.8/30 | 172.16.2.9 – 172.16.2.10 | 172.16.2.11 |
| 4 | 172.16.2.12/30 | 172.16.2.13 – 172.16.2.14 | 172.16.2.15 |
| 5 | 172.16.2.16/30 | 172.16.2.17 – 172.16.2.18 | 172.16.2.19 |
| 6 | 172.16.2.20/30 | 172.16.2.21 – 172.16.2.22 | 172.16.2.23 |
| 7 | 172.16.2.24/30 | 172.16.2.25 – 172.16.2.26 | 172.16.2.27 |
| 8 | 172.16.2.28/30 | 172.16.2.29 – 172.16.2.30 | 172.16.2.31 |
| 9 | 172.16.2.32/30 | 172.16.2.33 – 172.16.2.34 | 172.16.2.35 |
| 10 | 172.16.2.36/30 | 172.16.2.37 – 172.16.2.38 | 172.16.2.39 |
| 11 | 172.16.2.40/30 | 172.16.2.41 – 172.16.2.42 | 172.16.2.43 |
| 12 | 172.16.2.44/30 | 172.16.2.45 – 172.16.2.46 | 172.16.2.47 |
| 13 | 172.16.2.48/30 | 172.16.2.49 – 172.16.2.50 | 172.16.2.51 |
| 14 | 172.16.2.52/30 | 172.16.2.53 – 172.16.2.54 | 172.16.2.55 |
| 15 | 172.16.2.56/30 | 172.16.2.57 – 172.16.2.58 | 172.16.2.59 |
| 16 | 172.16.2.60/30 | 172.16.2.61 – 172.16.2.62 | 172.16.2.63 |
| 17 | 172.16.2.64/30 | 172.16.2.65 – 172.16.2.66 | 172.16.2.67 |
| 18 | 172.16.2.68/30 | 172.16.2.69 – 172.16.2.70 | 172.16.2.71 |
| 19 | 172.16.2.72/30 | 172.16.2.73 – 172.16.2.74 | 172.16.2.75 |
| 20 | 172.16.2.76/30 | 172.16.2.77 – 172.16.2.78 | 172.16.2.79 |
| 21 | 172.16.2.80/30 | 172.16.2.81 – 172.16.2.82 | 172.16.2.83 |
| 22 | 172.16.2.84/30 | 172.16.2.85 – 172.16.2.86 | 172.16.2.87 |
| 23 | 172.16.2.88/30 | 172.16.2.89 – 172.16.2.90 | 172.16.2.91 |
| 24 | 172.16.2.92/30 | 172.16.2.93 – 172.16.2.94 | 172.16.2.95 |
| 25 | 172.16.2.96/30 | 172.16.2.97 – 172.16.2.98 | 172.16.2.99 |
| 26 | 172.16.2.100/30 | 172.16.2.101 – 172.16.2.102 | 172.16.2.103 |
| 27 | 172.16.2.104/30 | 172.16.2.105 – 172.16.2.106 | 172.16.2.107 |
| 28 | 172.16.2.108/30 | 172.16.2.109 – 172.16.2.110 | 172.16.2.111 |
| 29 | 172.16.2.112/30 | 172.16.2.113 – 172.16.2.114 | 172.16.2.115 |
| 30 | 172.16.2.116/30 | 172.16.2.117 – 172.16.2.118 | 172.16.2.119 |
| 31 | 172.16.2.120/30 | 172.16.2.121 – 172.16.2.122 | 172.16.2.123 |
| 32 | 172.16.2.124/30 | 172.16.2.125 – 172.16.2.126 | 172.16.2.127 |
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.