Text & Developer Tools
Subnet Calculator
Calculate IPv4 network, broadcast, host range, and split CIDR blocks locally.
IP addresses are processed locally in your browser. Nothing is uploaded.
IPv4 subnet calculator
Enter an IPv4 address with a CIDR prefix. Network, host range, and mask are computed locally.
Network
Broadcast
Subnet mask
Wildcard
First host
Last host
Addresses
Usable hosts
Split into equal subnets
VLSM planner
Allocate variable-length subnets from the current CIDR. Enter one requirement per line as name, host count.
| Name | Hosts | Subnet | Usable range |
|---|
How CIDR works
The prefix is the number of leading network bits. A /24 leaves 8 host bits, giving 256 addresses and 254 usable hosts. A /31 is used for point-to-point links and a /32 identifies one address.