IPv4 Subnet Calculator

Calculate an IPv4 network address, broadcast address, subnet mask, host range, wildcard mask, and address count from CIDR notation.

An IPv4 subnet calculator turns an address and CIDR prefix, such as 192.168.1.10/24, into the network boundaries used by routers, firewalls, cloud networks, and local devices.

Enter an IPv4 address with a prefix from /0 to /32. The calculator runs in your browser and shows the network address, broadcast address, typical usable host range, subnet mask, wildcard mask, and total address count.

What CIDR notation means

The number after the slash tells you how many leading bits belong to the network. A /24 prefix leaves 8 host bits, producing 256 total IPv4 addresses.

Network and broadcast addresses

The network address is the first address in a subnet. In traditional IPv4 subnets, the broadcast address is the last address and sends traffic to all hosts on that subnet.

Usable host ranges

For prefixes from /0 through /30, the traditional usable range excludes the network and broadcast addresses. /31 is commonly used on point-to-point links, and /32 identifies one address.

Subnet masks and wildcard masks

A subnet mask marks the network bits with ones. A wildcard mask is its inverse and is often used in access-control and routing configuration.

Frequently Asked Questions

What is a /24 subnet mask?

A /24 corresponds to 255.255.255.0 and contains 256 total IPv4 addresses.

How many usable hosts are in a /28?

A traditional /28 has 16 total addresses and 14 usable host addresses.

Does this calculator support IPv6?

This version focuses on IPv4 CIDR calculations.