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IPv4 subnet calculator
Size your next IPv4 block in seconds. Enter any address and prefix to see host counts, network ranges and masks.
/24
/8/16/24/32
Total addresses
256
Usable hosts
254
Equivalent to 1 × /24 block — the smallest size routable on the public internet.
203.0.113.0/24
- Network address
- 203.0.113.0
- Broadcast address
- 203.0.113.255
- First usable host
- 203.0.113.1
- Last usable host
- 203.0.113.254
- Subnet mask
- 255.255.255.0
- Wildcard mask
- 0.0.0.255
IPv4 CIDR reference: /8 to /24
The most commonly traded block sizes on the IPv4 market. A /24 (256 addresses) is the smallest prefix generally accepted in the global BGP routing table.
| Prefix | Addresses | Subnet mask | /24 blocks |
|---|---|---|---|
| /8 | 16,777,216 | 255.0.0.0 | 65,536 |
| /9 | 8,388,608 | 255.128.0.0 | 32,768 |
| /10 | 4,194,304 | 255.192.0.0 | 16,384 |
| /11 | 2,097,152 | 255.224.0.0 | 8,192 |
| /12 | 1,048,576 | 255.240.0.0 | 4,096 |
| /13 | 524,288 | 255.248.0.0 | 2,048 |
| /14 | 262,144 | 255.252.0.0 | 1,024 |
| /15 | 131,072 | 255.254.0.0 | 512 |
| /16 | 65,536 | 255.255.0.0 | 256 |
| /17 | 32,768 | 255.255.128.0 | 128 |
| /18 | 16,384 | 255.255.192.0 | 64 |
| /19 | 8,192 | 255.255.224.0 | 32 |
| /20 | 4,096 | 255.255.240.0 | 16 |
| /21 | 2,048 | 255.255.248.0 | 8 |
| /22 | 1,024 | 255.255.252.0 | 4 |
| /23 | 512 | 255.255.254.0 | 2 |
| /24 | 256 | 255.255.255.0 | 1 |
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