Subnet/CIDR Calculator

Calculate network, broadcast address, and host count by IP and mask.

Network192.168.1.0
Broadcast192.168.1.255
First host192.168.1.1
Last host192.168.1.254
Netmask255.255.255.0
Wildcard mask0.0.0.255
Usable hosts254
Total addresses256

The subnet calculator computes network parameters for an IP address in CIDR format (e.g., 192.168.1.0/24): network address, broadcast address, host range, and subnet mask. Useful for VLAN planning, router configuration, or address space allocation.

What is CIDR notation?

CIDR (Classless Inter-Domain Routing) records the netmask as the number of consecutive one-bits after the slash, e.g., /24 corresponds to the 255.255.255.0 mask.

Why is the number of usable hosts less than the total?

The first address of the subnet is reserved for the network address, and the last is for the broadcast address; therefore, they cannot be assigned to hosts.

Is IPv6 supported?

Currently, the calculator only works with IPv4; please use a separate tool for IPv6 conversion.