Earth measurements Earth measurements were the standard units of measure used in the United Federation of Planets . Length . Meter . A meter ( m ) was the fundamental SI unit of length , defined as the distance traveled by light in a vacuum in 1 / 299 , 792 , 458 second . In the Imperial units system , 1 foot ≡ 0 . 3048 m . Nanometer . A nanometer ( nm ) was an SI unit of length equal to one billionth of a meter ( 1 m ) . 1 nm ≈ 0 . 00000000003937 inches . Millimeter . A millimeter ( mm ) was an SI unit of length equal to 1 / 1 , 000 of a meter . 1 mm ≈ 0 . 03937 inches . Centimeter . A centimeter ( cm ) was an SI unit of length equal to 1 / 100 of a meter . 1 cm ≈ 0 . 3937 inches . " Lucille Harewood ' s height was given in centimeters on her medical status display at Royal Children ' s Hospital in an alternate reality 2259 . ( ) " In 2374 , Odo tricked Miles O ' Brien and Julian Bashir into believing that they were still a couple of centimetres shorter than normal after being shrunk and regrown again . ( ) Kilometer . A kilometer ( km ) was an SI unit of length equal to one thousand meters . 1 km ≈ 0 . 62137 miles . Micron . A micron was another name for micrometer ( µm ) , an SI unit of length equal to 1 millionth of a meter ( 1 m ) . 1 mil ≡ 25 . 4 μm . The absorption depth of osmium alloy was at least twenty - thousand particle s per micron . ( ) Mile . A mile ( mi ) was originally one thousand paces , or 5 , 000 Roman feet ( ∼4 , 850 Imperial feet ) . A later British reform changed the mile to 5 , 280 Imperial feet so that it would equal eight furlongs . 1 mi ≡ 1 . 609344 km . Nautical mile . A nautical mile was based on the length of one minute of arc of a great circle . 1 nautical mile ≡ 1 , 852 m ( ∼6 , 076 . 12 ft ) Foot . A foot ( ft , plural feet ) was an Imperial unit of length equal to twelve inches , or one third of a yard . 1 ft ≡ 0 . 3048 m . Inch . An inch ( in ) was originally based on the width of the average man ' s thumb , or the length of three barley - corns . It was later redefined based on SI units . 1 in ≡ 2 . 54 cm . A passage from Alice ' s Adventures in Wonderland described Alice being only ten inches high . ( ) Light year . One light year was the distance that light traveled in one Earth year . It was approximately equal to 9 . 46 meters , or 5 . 88 miles . Mass . Kilogram . A kilogram ( kg ) was the fundamental SI unit of mass . In the Imperial units system , 1 pound ≡ 0 . 45359237 kg . " Lucille Harewood ' s weight was given in kilograms on her medical status display at Royal Children ' s Hospital in an alternate reality 2259 . " ( ) Gram . A gram ( g ) was an SI unit of mass equal to 1 / 1 , 000 of a kilogram . 1 ounce ≡ 28 . 349523125 g . Milligram . A milligram ( mg ) was an SI unit of mass equal to 1 / 1 , 000 of a gram . Time . See : Time measurements Volume . Liter . A liter ( L or l ) was a derived SI unit of volume , equal to 1 / 1 , 000 cubic meters ( 1 cubic decimeter ) . In the Imperial units system , 1 gallon ≡ 4 . 54609 L ( ∼277 . 42 cubic inches ) . In the US system , 1 gallon ≡ 231 cubic inches ≡ 3 . 785411784 L . Milliliter . A milliliter ( ml ) was an SI unit of volume equal to 1 / 1 , 000 of a liter . In the Imperial system , 1 fluid ounce ≡ 28 . 4130625 ml . In the US system , 1 fluid ounce ≡ 29 . 5735295625 ml . cc . A cc ( cubic centimeter , official cm ) was a measure of volume equal to one cubic centimeter ( cm ) , which was also equal to one milliliter ( ml ) . The cc was a common term for milliliters used in measuring the dosage of liquid medicines by volume . 1 cubic inch ≡ 16 . 387064 ml ≡ 16 . 387064 cc . Cubic meter . When the crew was forced to take shelter in the ship ' s catwalk , T ' Pol allowed Doctor Phlox fifteen cubic meters of space for his medical supply . Phlox later discussed this with T ' Pol and she allowed him five more cubic meters to what Phlox answered , " " my Edosian slug s thank you . " " ( ) During a sensor sweep of the neutral zone , the found 25 particles of dust per cubic meter . ( ) Units . Gross . A gross was equal to a dozen dozen .