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)10.0.19.128/25
network10.0.19.128/25
broadcast10.0.19.255
first host10.0.19.129
last host10.0.19.254
subnet mask255.255.255.128
wildcard0.0.0.127
addresses128
usable hosts126
classA
ipcalc 10.0.19.128/25
address00001010.00000000.00010011.10000000
subnet mask11111111.11111111.11111111.10000000
network00001010.00000000.00010011.10000000
broadcast00001010.00000000.00010011.11111111
green = network part, grey = host part
hex0x0a001380
decimal167777152
reverse dns128.19.0.10.in-addr.arpa
ipv4-mapped::ffff:a00:1380
/25 split into /30 · 32 subnets
close ×| # | network | host range | broadcast |
|---|---|---|---|
| 1 | 10.0.19.128/30 | 10.0.19.129 – 10.0.19.130 | 10.0.19.131 |
| 2 | 10.0.19.132/30 | 10.0.19.133 – 10.0.19.134 | 10.0.19.135 |
| 3 | 10.0.19.136/30 | 10.0.19.137 – 10.0.19.138 | 10.0.19.139 |
| 4 | 10.0.19.140/30 | 10.0.19.141 – 10.0.19.142 | 10.0.19.143 |
| 5 | 10.0.19.144/30 | 10.0.19.145 – 10.0.19.146 | 10.0.19.147 |
| 6 | 10.0.19.148/30 | 10.0.19.149 – 10.0.19.150 | 10.0.19.151 |
| 7 | 10.0.19.152/30 | 10.0.19.153 – 10.0.19.154 | 10.0.19.155 |
| 8 | 10.0.19.156/30 | 10.0.19.157 – 10.0.19.158 | 10.0.19.159 |
| 9 | 10.0.19.160/30 | 10.0.19.161 – 10.0.19.162 | 10.0.19.163 |
| 10 | 10.0.19.164/30 | 10.0.19.165 – 10.0.19.166 | 10.0.19.167 |
| 11 | 10.0.19.168/30 | 10.0.19.169 – 10.0.19.170 | 10.0.19.171 |
| 12 | 10.0.19.172/30 | 10.0.19.173 – 10.0.19.174 | 10.0.19.175 |
| 13 | 10.0.19.176/30 | 10.0.19.177 – 10.0.19.178 | 10.0.19.179 |
| 14 | 10.0.19.180/30 | 10.0.19.181 – 10.0.19.182 | 10.0.19.183 |
| 15 | 10.0.19.184/30 | 10.0.19.185 – 10.0.19.186 | 10.0.19.187 |
| 16 | 10.0.19.188/30 | 10.0.19.189 – 10.0.19.190 | 10.0.19.191 |
| 17 | 10.0.19.192/30 | 10.0.19.193 – 10.0.19.194 | 10.0.19.195 |
| 18 | 10.0.19.196/30 | 10.0.19.197 – 10.0.19.198 | 10.0.19.199 |
| 19 | 10.0.19.200/30 | 10.0.19.201 – 10.0.19.202 | 10.0.19.203 |
| 20 | 10.0.19.204/30 | 10.0.19.205 – 10.0.19.206 | 10.0.19.207 |
| 21 | 10.0.19.208/30 | 10.0.19.209 – 10.0.19.210 | 10.0.19.211 |
| 22 | 10.0.19.212/30 | 10.0.19.213 – 10.0.19.214 | 10.0.19.215 |
| 23 | 10.0.19.216/30 | 10.0.19.217 – 10.0.19.218 | 10.0.19.219 |
| 24 | 10.0.19.220/30 | 10.0.19.221 – 10.0.19.222 | 10.0.19.223 |
| 25 | 10.0.19.224/30 | 10.0.19.225 – 10.0.19.226 | 10.0.19.227 |
| 26 | 10.0.19.228/30 | 10.0.19.229 – 10.0.19.230 | 10.0.19.231 |
| 27 | 10.0.19.232/30 | 10.0.19.233 – 10.0.19.234 | 10.0.19.235 |
| 28 | 10.0.19.236/30 | 10.0.19.237 – 10.0.19.238 | 10.0.19.239 |
| 29 | 10.0.19.240/30 | 10.0.19.241 – 10.0.19.242 | 10.0.19.243 |
| 30 | 10.0.19.244/30 | 10.0.19.245 – 10.0.19.246 | 10.0.19.247 |
| 31 | 10.0.19.248/30 | 10.0.19.249 – 10.0.19.250 | 10.0.19.251 |
| 32 | 10.0.19.252/30 | 10.0.19.253 – 10.0.19.254 | 10.0.19.255 |
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 /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.