A subnet calculator takes an IP address and CIDR prefix length (like /24) and computes the network address, broadcast address, subnet mask, and total usable host addresses.
About this calculator
A subnet calculator takes an IP address and CIDR prefix length (like /24) and computes the network address, broadcast address, subnet mask, and total usable host addresses. Subnetting is a basic part of network design and IP address management.
It is useful for network engineers, system administrators, and anyone managing network infrastructure.
Common uses
- Find the network address and broadcast address for a subnet
- Calculate how many hosts fit in a /24 or /16 subnet
- Design IP address allocation for a network
- Troubleshoot IP addressing conflicts in a network
Frequently asked questions
How many hosts does a /24 subnet support?
A /24 subnet has 32 − 24 = 8 host bits, giving 2^8 = 256 total addresses. Subtracting the network address and broadcast address leaves 254 usable host addresses. Common subnets: /30 = 2 hosts, /29 = 6, /28 = 14, /27 = 30, /26 = 62, /25 = 126, /24 = 254, /23 = 510, /16 = 65,534.