Subnet (CIDR) Calculator
Calculate subnet information from an IP address and subnet mask.
IP address
Subnet mask
- Safe
- Processing runs on your device, so input/output is not sent anywhere.
Explanation
Based on the entered IPv4 address and subnet mask (CIDR), this tool calculates and displays the following information.
| IP range | Network start and end address |
|---|---|
| Address count | Number of IP addresses available within the specified subnet |
| Class | The class the IP address belongs to |
CIDR Subnet Mask Table
A list of subnet information based on CIDR notation for IPv4 addresses.
| Class | CIDR | Subnet mask | Address count |
|---|---|---|---|
| - | /1 | 128.0.0.0 | 2,147,483,648 |
| /2 | 192.0.0.0 | 1,073,741,824 | |
| /3 | 224.0.0.0 | 536,870,912 | |
| /4 | 240.0.0.0 | 268,435,456 | |
| /5 | 248.0.0.0 | 134,217,728 | |
| /6 | 252.0.0.0 | 67,108,864 | |
| /7 | 254.0.0.0 | 33,554,432 | |
| Class A | /8 | 255.0.0.0 | 16,777,216 |
| /9 | 255.128.0.0 | 8,388,608 | |
| /10 | 255.192.0.0 | 4,194,304 | |
| /11 | 255.224.0.0 | 2,097,152 | |
| /12 | 255.240.0.0 | 1,048,576 | |
| /13 | 255.248.0.0 | 524,288 | |
| /14 | 255.252.0.0 | 262,144 | |
| /15 | 255.254.0.0 | 131,072 | |
| Class B | /16 | 255.255.0.0 | 65,536 |
| /17 | 255.255.128.0 | 32,768 | |
| /18 | 255.255.192.0 | 16,384 | |
| /19 | 255.255.224.0 | 8,192 | |
| /20 | 255.255.240.0 | 4,096 | |
| /21 | 255.255.248.0 | 2,048 | |
| /22 | 255.255.252.0 | 1,024 | |
| /23 | 255.255.254.0 | 512 | |
| Class C | /24 | 255.255.255.0 | 256 |
| /25 | 255.255.255.128 | 128 | |
| /26 | 255.255.255.192 | 64 | |
| /27 | 255.255.255.224 | 32 | |
| /28 | 255.255.255.240 | 16 | |
| /29 | 255.255.255.248 | 8 | |
| /30 | 255.255.255.252 | 4 | |
| /31 | 255.255.255.254 | 2 | |
| /32 | 255.255.255.255 | 1 |