THE TOOLKIT

Everyday utilities

Work with everyday numbers in a few clear steps. Each tool explains its inputs, results and limits before you start.

Convert Latin letters, digits and common punctuation to Morse code, or decode dot-dash symbols.

Convert numbers from 1 to 3999 into Roman numerals, or decode canonical Roman numerals.

Convert unsigned integers between decimal, binary and hexadecimal, or convert UTF-8 text to binary bytes and back.

Check the Gregorian leap-year rule and see the number of days in February and the year.

Calculate a percentage of a number, percentage change or symmetric percentage difference.

Check the local Luhn checksum of a 15-digit IMEI without sending the identifier to a server.

Calculate cost per GB, prorated data usage cost and fixed fees from your own plan prices.