Roman units
Convert Roman length units with an explicitly selected 296 mm foot reference.
Historical units
Egyptian cubits
Convert royal and common cubits, palms, and digits using a named archaeological reference.
Ancient Greek units
Convert lengths using the Doric foot profile studied at Makyneia in western Greece.
Historical English measures
Convert rods, chains, furlongs, and other English lengths using a modern SI yard reference.
Roman numerals
Convert numbers 1–3999 and standard subtractive Roman numerals in either direction.
Julian / Gregorian dates
Convert the same civil day between explicitly selected Julian and Gregorian calendars.