DevSecOps
CIDR Calculator
Enter any CIDR notation block and instantly get the full subnet breakdown: network address, broadcast address, first and last usable host, total host count, subnet mask, and wildcard mask. Built for network and cloud engineers.
No data is transmitted — everything runs locallyTool
About this tool
CIDR Calculator
The CIDR Calculator computes the full subnet breakdown for any CIDR block, including network address, broadcast, usable host range, subnet mask, and host count.
• Plan VPC subnet allocation for AWS, GCP, or Azure
• Calculate host capacity before provisioning a network segment
• Verify CIDR ranges before adding firewall rules
• Convert between subnet mask notation and prefix length
Affiliate disclosure
Developer-friendly cloud infrastructure. DigitalOcean provides cloud compute, networking, and managed databases with predictable pricing.
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FAQ
What does this tool tell you?
The CIDR Calculator computes the full subnet breakdown for any CIDR block, including network address, broadcast, usable host range, subnet mask, and host count.
What affects the result most?
Prefix length (/8 through /32). Network class (A/B/C — historical but still referenced). Host count = 2^(32-prefix) - 2 usable.
How should I use the result?
The calculation is deterministic — the same inputs always produce the same output — so the most useful workflow is to vary one input at a time and see which factor moves the result most. That tells you where to focus your attention before committing to a decision.
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