Developer Utility
CIDR Range Calculator Tool
Calculate start and end IP ranges from IPv4 or IPv6 CIDR blocks.
Language: TextUtility: ParseUtility: InspectUtility: Convert
Family: IPv6 Input: 2001:db8::/64 Prefix: /64 Range start: 2001:db8:: Range end: 2001:db8::ffff:ffff:ffff:ffff Total addresses: 18446744073709551616
What This Tool Does
Compute network start and end addresses for IPv4 and IPv6 CIDR blocks.
Use it to inspect or transform input quickly, then carry validated output into code, tests, or API requests.
Common Use Cases
- Review allocation boundaries before firewall or route changes.
- Verify cloud CIDR assignments quickly.
- Generate clear range notes for handoff documentation.
Common Pitfalls
- Very large prefixes can represent huge ranges that still require policy controls.
- Incorrect prefix lengths produce misleading boundaries.
FAQ
Does this support both IPv4 and IPv6?
Yes, CIDR ranges are calculated for either family.
Is host usability included?
The tool focuses on start/end range boundaries; subnet tool covers host semantics.
Does this tool send data to a backend?
Most tools process input client-side in your browser unless explicitly noted.