IPv6 Calculator

Enter an address and prefix — full and compressed form, network address, address range, contained /64s, reverse DNS and the type follow immediately.

Notes

Runs in your browser. The calculation happens entirely on your device. Nothing you type is transmitted, stored or analysed.
Compression per RFC 5952. The longest run of zeros is collapsed to ::, everything in lower case.
Very large numbers. Address counts beyond what is sensible to print are shown as a power of ten, e.g. 2^64.