CIDR

CIDR Range Converter

Convert CIDR blocks and IP ranges

IP & Routing
πŸ”’ 100% client-side β€” your data never leaves this page
English version/Chinese version
Page mode
Input

Quick CTA

Paste a CIDR or IP range first to convert between CIDR and range immediately; edge cases stay in Deep.

Output
Network conversion result will appear here
πŸ”’ 100% client-side

Next step workflow

Split this block into smaller subnetsMerge adjacent CIDR resultsInspect host and mask details
Page reading mode

Quick keeps the summary, direct answers, and next steps so you can validate fit and get a result faster.

About this tool

Convert IPv4 CIDR blocks into network/broadcast/host ranges and convert start-end IP ranges into minimal CIDR block lists. This is useful for firewall allowlists, cloud security group setup, route table design, and subnet audits. Output includes subnet mask, total addresses, usable hosts, and compact CIDR blocks. Everything runs locally in your browser.

Suggested Workflow

Network ACL Change Checklist Before Production Rollout

Plan CIDR boundaries, verify host ranges, and reduce firewall mistakes in change windows.

Direct Answers

Why convert between CIDR and IP ranges?

Because network plans and firewall rules often switch between block notation and explicit start-end ranges.

Can one range become multiple CIDR blocks?

Yes. Many arbitrary ranges require several CIDR blocks to represent them efficiently.