CIDR Subnet Calculator

Calculate network ranges, subnet masks, usable host IP addresses, and broadcast details instantly from any CIDR block.

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CIDR Notation Reference

1. Subnet Mask Mapping

The prefix length (e.g., /24) indicates how many bits are set to 1 in the 32-bit subnet mask, determining network size.

2. Usable Host Allocation

Total available addresses minus two reserved addresses (Network ID and Broadcast address) yield the total usable hosts.

Frequently Asked Questions (FAQ)

Classless Inter-Domain Routing (CIDR) is a method for allocating IP addresses and routing IP packets, combining an IP address with a slash and a decimal number indicating the routing prefix bits.

The first address in any subnet is reserved as the Network Identifier, and the final address is reserved as the Broadcast Address, leaving the remaining intermediate addresses for host configuration.

Yes. All subnet and bitwise calculations are executed completely client-side within your browser instance.