angstrom astronomical unit chain centimetre decametre decimetre fathom femtometre foot hectometre inch kilometre light year metre milli- inch mile (statute mile) millimetre nautical mile nanometre parsec picometre micro- inch micrometre (micron) yard centigram hundred weight (UK) hundred pounds (cwt)/ hundred weight (US) decagram decigram decitonne gram grain hectogram kilogram kilotonne pound milligram megagram ounce stone (UK) tonne (metric ton) ton (UK) or longton (US) ton (US) or short ton (UK/US) troy ounce or apothecaries' ounce year tropical year day hour kilosecond minute millisecond nanosecond second microsecond centimetre per second foot per minute foot per second inch per second kilometre per hour knot metre per minute metre per second mile per hour millimetre per second