CIDR to IP Range Converter

Convert Any CIDR Block to Its Full IP Range

CIDR Block

IP Range

The IP range will appear here

Error

Please enter a valid CIDR block.

Understanding CIDR Ranges

Firewall Rules

Quickly determine the full range a firewall or ACL rule referencing a CIDR block will actually cover.

Network Planning

Calculate usable host counts when sizing a subnet for a new VLAN or cloud VPC.

Troubleshooting

Verify whether a specific IP address falls inside a documented CIDR range.

Client-Side Only

All calculation happens locally in your browser — no data is ever sent to a server.

Network, Broadcast, and Usable Range

Every IPv4 subnet reserves its first address for the network identifier and (except for /31 and /32) its last address for broadcast, leaving the addresses in between usable for hosts. This tool computes all of these boundaries automatically from a single CIDR notation input.

Key Takeaways

Full Boundary Detail: See network, broadcast, first/last usable, and total host counts in one result.
RFC-Correct Edge Cases: Handles /31 point-to-point links and /32 host routes per their special rules.
Client-Side Only: All calculation happens locally in your browser — no data is ever sent to a server.

CIDR to IP Range Converter - Free Online Tool