Subnet Calculator limitationsResults are mathematical calculations based solely on the entered IPv4 address and prefix.
The calculator does not inspect, validate or change a live router, VLAN, DHCP scope, firewall or network. Confirm addressing plans and reserved addresses against the actual environment before implementation.
Important: Do not rely on this result alone for purchasing, configuration, security, safety, compliance, contractual or fault-diagnosis decisions. Results can be incomplete, delayed, misleading or wrong. Verify important findings with the relevant provider, manufacturer documentation and an appropriate independent test or qualified professional.
Network diagnostics
IPv4 Subnet Calculator
Calculate an IPv4 network address, broadcast address, usable host range, subnet mask and wildcard mask. You can also convert an IP range into CIDR blocks or size a subnet for a required number of devices.
Results
0 calculations recorded
CIDR planning tools
Plan address ranges and subnet capacity
Convert an exact IPv4 range into the smallest possible set of CIDR blocks, or find the smallest traditional subnet that can support the number of usable devices you require.
IPv4 subnet reference table
Compare every IPv4 CIDR prefix with its subnet mask, total address capacity and usable address capacity. Traditional subnets exclude the network and broadcast addresses; /31 and /32 use the point-to-point and single-host exceptions shown below.
| CIDR prefix | Subnet mask | Total addresses | Usable addresses | Notes |
|---|---|---|---|---|
| /0 | 0.0.0.0 | 4,294,967,296 | 4,294,967,294 | Standard IPv4 subnet |
| /1 | 128.0.0.0 | 2,147,483,648 | 2,147,483,646 | Standard IPv4 subnet |
| /2 | 192.0.0.0 | 1,073,741,824 | 1,073,741,822 | Standard IPv4 subnet |
| /3 | 224.0.0.0 | 536,870,912 | 536,870,910 | Standard IPv4 subnet |
| /4 | 240.0.0.0 | 268,435,456 | 268,435,454 | Standard IPv4 subnet |
| /5 | 248.0.0.0 | 134,217,728 | 134,217,726 | Standard IPv4 subnet |
| /6 | 252.0.0.0 | 67,108,864 | 67,108,862 | Standard IPv4 subnet |
| /7 | 254.0.0.0 | 33,554,432 | 33,554,430 | Standard IPv4 subnet |
| /8 | 255.0.0.0 | 16,777,216 | 16,777,214 | Standard IPv4 subnet |
| /9 | 255.128.0.0 | 8,388,608 | 8,388,606 | Standard IPv4 subnet |
| /10 | 255.192.0.0 | 4,194,304 | 4,194,302 | Standard IPv4 subnet |
| /11 | 255.224.0.0 | 2,097,152 | 2,097,150 | Standard IPv4 subnet |
| /12 | 255.240.0.0 | 1,048,576 | 1,048,574 | Standard IPv4 subnet |
| /13 | 255.248.0.0 | 524,288 | 524,286 | Standard IPv4 subnet |
| /14 | 255.252.0.0 | 262,144 | 262,142 | Standard IPv4 subnet |
| /15 | 255.254.0.0 | 131,072 | 131,070 | Standard IPv4 subnet |
| /16 | 255.255.0.0 | 65,536 | 65,534 | Standard IPv4 subnet |
| /17 | 255.255.128.0 | 32,768 | 32,766 | Standard IPv4 subnet |
| /18 | 255.255.192.0 | 16,384 | 16,382 | Standard IPv4 subnet |
| /19 | 255.255.224.0 | 8,192 | 8,190 | Standard IPv4 subnet |
| /20 | 255.255.240.0 | 4,096 | 4,094 | Standard IPv4 subnet |
| /21 | 255.255.248.0 | 2,048 | 2,046 | Standard IPv4 subnet |
| /22 | 255.255.252.0 | 1,024 | 1,022 | Standard IPv4 subnet |
| /23 | 255.255.254.0 | 512 | 510 | Standard IPv4 subnet |
| /24 | 255.255.255.0 | 256 | 254 | Common small network |
| /25 | 255.255.255.128 | 128 | 126 | Standard IPv4 subnet |
| /26 | 255.255.255.192 | 64 | 62 | Standard IPv4 subnet |
| /27 | 255.255.255.224 | 32 | 30 | Standard IPv4 subnet |
| /28 | 255.255.255.240 | 16 | 14 | Standard IPv4 subnet |
| /29 | 255.255.255.248 | 8 | 6 | Standard IPv4 subnet |
| /30 | 255.255.255.252 | 4 | 2 | Standard IPv4 subnet |
| /31 | 255.255.255.254 | 2 | 2 | Point-to-point subnet |
| /32 | 255.255.255.255 | 1 | 1 | Single-host route |