Subnet Calculator
Calculates network address, broadcast address and host range from an IP and CIDR.
Lilu Baba's Subnet Calculator works out the full subnet details — network address, broadcast address, mask and usable host range — from any IPv4 address and CIDR prefix.
How to use this tool
- Enter an IPv4 address and its CIDR prefix.
- Network address, broadcast address, subnet mask and usable host range update instantly.
FAQ
Subnet Calculator — frequently asked questions
A number (0-32) indicating how many leading bits of the 32-bit IPv4 address are the network portion — e.g. /24 means a 255.255.255.0 mask.
The first address in a subnet is the network address and the last is the broadcast address — neither can be assigned to a host (except in /31 and /32 subnets).