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)172.16.12.0/24
network172.16.12.0/24
broadcast172.16.12.255
first host172.16.12.1
last host172.16.12.254
subnet mask255.255.255.0
wildcard0.0.0.255
addresses256
usable hosts254
classB
ipcalc 172.16.12.0/24
address10101100.00010000.00001100.00000000
subnet mask11111111.11111111.11111111.00000000
network10101100.00010000.00001100.00000000
broadcast10101100.00010000.00001100.11111111
green = network part, grey = host part
hex0xac100c00
decimal2886732800
reverse dns0.12.16.172.in-addr.arpa
ipv4-mapped::ffff:ac10:c00
/24 split into /30 · 64 subnets
close ×| # | network | host range | broadcast |
|---|---|---|---|
| 1 | 172.16.12.0/30 | 172.16.12.1 – 172.16.12.2 | 172.16.12.3 |
| 2 | 172.16.12.4/30 | 172.16.12.5 – 172.16.12.6 | 172.16.12.7 |
| 3 | 172.16.12.8/30 | 172.16.12.9 – 172.16.12.10 | 172.16.12.11 |
| 4 | 172.16.12.12/30 | 172.16.12.13 – 172.16.12.14 | 172.16.12.15 |
| 5 | 172.16.12.16/30 | 172.16.12.17 – 172.16.12.18 | 172.16.12.19 |
| 6 | 172.16.12.20/30 | 172.16.12.21 – 172.16.12.22 | 172.16.12.23 |
| 7 | 172.16.12.24/30 | 172.16.12.25 – 172.16.12.26 | 172.16.12.27 |
| 8 | 172.16.12.28/30 | 172.16.12.29 – 172.16.12.30 | 172.16.12.31 |
| 9 | 172.16.12.32/30 | 172.16.12.33 – 172.16.12.34 | 172.16.12.35 |
| 10 | 172.16.12.36/30 | 172.16.12.37 – 172.16.12.38 | 172.16.12.39 |
| 11 | 172.16.12.40/30 | 172.16.12.41 – 172.16.12.42 | 172.16.12.43 |
| 12 | 172.16.12.44/30 | 172.16.12.45 – 172.16.12.46 | 172.16.12.47 |
| 13 | 172.16.12.48/30 | 172.16.12.49 – 172.16.12.50 | 172.16.12.51 |
| 14 | 172.16.12.52/30 | 172.16.12.53 – 172.16.12.54 | 172.16.12.55 |
| 15 | 172.16.12.56/30 | 172.16.12.57 – 172.16.12.58 | 172.16.12.59 |
| 16 | 172.16.12.60/30 | 172.16.12.61 – 172.16.12.62 | 172.16.12.63 |
| 17 | 172.16.12.64/30 | 172.16.12.65 – 172.16.12.66 | 172.16.12.67 |
| 18 | 172.16.12.68/30 | 172.16.12.69 – 172.16.12.70 | 172.16.12.71 |
| 19 | 172.16.12.72/30 | 172.16.12.73 – 172.16.12.74 | 172.16.12.75 |
| 20 | 172.16.12.76/30 | 172.16.12.77 – 172.16.12.78 | 172.16.12.79 |
| 21 | 172.16.12.80/30 | 172.16.12.81 – 172.16.12.82 | 172.16.12.83 |
| 22 | 172.16.12.84/30 | 172.16.12.85 – 172.16.12.86 | 172.16.12.87 |
| 23 | 172.16.12.88/30 | 172.16.12.89 – 172.16.12.90 | 172.16.12.91 |
| 24 | 172.16.12.92/30 | 172.16.12.93 – 172.16.12.94 | 172.16.12.95 |
| 25 | 172.16.12.96/30 | 172.16.12.97 – 172.16.12.98 | 172.16.12.99 |
| 26 | 172.16.12.100/30 | 172.16.12.101 – 172.16.12.102 | 172.16.12.103 |
| 27 | 172.16.12.104/30 | 172.16.12.105 – 172.16.12.106 | 172.16.12.107 |
| 28 | 172.16.12.108/30 | 172.16.12.109 – 172.16.12.110 | 172.16.12.111 |
| 29 | 172.16.12.112/30 | 172.16.12.113 – 172.16.12.114 | 172.16.12.115 |
| 30 | 172.16.12.116/30 | 172.16.12.117 – 172.16.12.118 | 172.16.12.119 |
| 31 | 172.16.12.120/30 | 172.16.12.121 – 172.16.12.122 | 172.16.12.123 |
| 32 | 172.16.12.124/30 | 172.16.12.125 – 172.16.12.126 | 172.16.12.127 |
| 33 | 172.16.12.128/30 | 172.16.12.129 – 172.16.12.130 | 172.16.12.131 |
| 34 | 172.16.12.132/30 | 172.16.12.133 – 172.16.12.134 | 172.16.12.135 |
| 35 | 172.16.12.136/30 | 172.16.12.137 – 172.16.12.138 | 172.16.12.139 |
| 36 | 172.16.12.140/30 | 172.16.12.141 – 172.16.12.142 | 172.16.12.143 |
| 37 | 172.16.12.144/30 | 172.16.12.145 – 172.16.12.146 | 172.16.12.147 |
| 38 | 172.16.12.148/30 | 172.16.12.149 – 172.16.12.150 | 172.16.12.151 |
| 39 | 172.16.12.152/30 | 172.16.12.153 – 172.16.12.154 | 172.16.12.155 |
| 40 | 172.16.12.156/30 | 172.16.12.157 – 172.16.12.158 | 172.16.12.159 |
| 41 | 172.16.12.160/30 | 172.16.12.161 – 172.16.12.162 | 172.16.12.163 |
| 42 | 172.16.12.164/30 | 172.16.12.165 – 172.16.12.166 | 172.16.12.167 |
| 43 | 172.16.12.168/30 | 172.16.12.169 – 172.16.12.170 | 172.16.12.171 |
| 44 | 172.16.12.172/30 | 172.16.12.173 – 172.16.12.174 | 172.16.12.175 |
| 45 | 172.16.12.176/30 | 172.16.12.177 – 172.16.12.178 | 172.16.12.179 |
| 46 | 172.16.12.180/30 | 172.16.12.181 – 172.16.12.182 | 172.16.12.183 |
| 47 | 172.16.12.184/30 | 172.16.12.185 – 172.16.12.186 | 172.16.12.187 |
| 48 | 172.16.12.188/30 | 172.16.12.189 – 172.16.12.190 | 172.16.12.191 |
| 49 | 172.16.12.192/30 | 172.16.12.193 – 172.16.12.194 | 172.16.12.195 |
| 50 | 172.16.12.196/30 | 172.16.12.197 – 172.16.12.198 | 172.16.12.199 |
| 51 | 172.16.12.200/30 | 172.16.12.201 – 172.16.12.202 | 172.16.12.203 |
| 52 | 172.16.12.204/30 | 172.16.12.205 – 172.16.12.206 | 172.16.12.207 |
| 53 | 172.16.12.208/30 | 172.16.12.209 – 172.16.12.210 | 172.16.12.211 |
| 54 | 172.16.12.212/30 | 172.16.12.213 – 172.16.12.214 | 172.16.12.215 |
| 55 | 172.16.12.216/30 | 172.16.12.217 – 172.16.12.218 | 172.16.12.219 |
| 56 | 172.16.12.220/30 | 172.16.12.221 – 172.16.12.222 | 172.16.12.223 |
| 57 | 172.16.12.224/30 | 172.16.12.225 – 172.16.12.226 | 172.16.12.227 |
| 58 | 172.16.12.228/30 | 172.16.12.229 – 172.16.12.230 | 172.16.12.231 |
| 59 | 172.16.12.232/30 | 172.16.12.233 – 172.16.12.234 | 172.16.12.235 |
| 60 | 172.16.12.236/30 | 172.16.12.237 – 172.16.12.238 | 172.16.12.239 |
| 61 | 172.16.12.240/30 | 172.16.12.241 – 172.16.12.242 | 172.16.12.243 |
| 62 | 172.16.12.244/30 | 172.16.12.245 – 172.16.12.246 | 172.16.12.247 |
| 63 | 172.16.12.248/30 | 172.16.12.249 – 172.16.12.250 | 172.16.12.251 |
| 64 | 172.16.12.252/30 | 172.16.12.253 – 172.16.12.254 | 172.16.12.255 |
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 /24 |
|---|---|---|---|---|
| /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 | 1 |
| /25 | 255.255.255.128 | 128 | 126 | 2 split → |
| /26 | 255.255.255.192 | 64 | 62 | 4 split → |
| /27 | 255.255.255.224 | 32 | 30 | 8 split → |
| /28 | 255.255.255.240 | 16 | 14 | 16 split → |
| /29 | 255.255.255.248 | 8 | 6 | 32 split → |
| /30 | 255.255.255.252 | 4 | 2 | 64 split → |
| /31 | 255.255.255.254 | 2 | 2 | 128 split → |
| /32 | 255.255.255.255 | 1 | 1 | 256 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.