NETWORK UTILITY

Subnet Calculator

Calculate an IPv4 subnet locally in your browser—network address, broadcast, mask, wildcard and host range.

IPv4 Subnet CalculatorBrowser-only

Static example

192.168.1.25/24 belongs to network 192.168.1.0/24, whose broadcast address is 192.168.1.255. Private examples are safe for learning; the calculator runs entirely in your browser.

What this calculator does

It converts IPv4 CIDR notation into network boundaries, subnet mask, wildcard mask, address count and usable-host range. No entered address is sent to our server.

Why CIDR matters

Classless Inter-Domain Routing uses a prefix length such as /24 to describe how many leading bits identify the network. A longer prefix creates a smaller address block; a shorter prefix creates a larger one.

Operational note

For /31 point-to-point networks and /32 host routes, the traditional network/broadcast host rules differ. The calculator reports both addresses as usable for /31 and the single address for /32.

How to read the subnet result

The network address is the first address in the calculated block and identifies the subnet itself. The broadcast address is the last address under traditional IPv4 subnetting. The subnet mask and CIDR prefix describe the same boundary in different notation, while the wildcard mask is the inverse mask commonly seen in network rules and access-control configuration.

When is a subnet calculator useful?

It is useful when designing LANs, reviewing firewall rules, checking whether two IPv4 addresses belong to the same network, interpreting cloud-network CIDR blocks or validating documentation. Because the arithmetic runs locally in your browser, private RFC1918 addresses can be calculated without sending them to the server.

Why usable hosts can differ from total addresses

Traditional IPv4 subnets reserve the network and broadcast addresses, so a /24 has 256 total addresses but normally 254 traditional host addresses. /31 point-to-point networks and /32 host routes are special cases, which the calculator handles separately.