About this utility
How to use IPv6 CIDR Calculator
Normalize IPv6 addresses and calculate network ranges, host counts, reverse DNS, and IPv4-mapped details.
What to provide
Enter an IPv6 address with an optional prefix, for example 2001:db8:85a3::8a2e:370:7334/64.
- Paste, type, or drag and drop a supported text file into the input area.
- Review the input and the clearly labeled output behavior.
- Select “Run tool” or press Ctrl/Command + Enter, then copy, download, or move the result back into the first input for another pass.
What the result means
Expanded/compressed forms, network boundaries, prefix, address count, scope, and reverse-DNS name.
Privacy and safety
This utility is loaded as browser code and processes your input only in this tab. OmniCastConverter has no upload endpoint and never stores your content, filenames, tokens, or secrets. Generated markup and code are shown as inert text and are never executed.
Limitations
- The tool performs address mathematics only; it does not test reachability, routing, ownership, or DNS delegation.
Try the included example
Select “Load example” at any time to restore this tested sample.
2001:db8:85a3::8a2e:370:7334/64