Roman System of Weights and Measures
ROMAN UNIT MODERN APPROXIMATION MODERN ENGLISH / METRIC ROMAN UNITS
Linear Distance
Mille passus Passus Pes (pl. pedes) Uncia (pl. unciae) Stadium (pl. stadia) Actus Roman Mile Roman Yard Roman Foot Roman Inch Roman Nautical Unit Roman Land Unit 1618 yds / 1480 m Equivalent to 1000 passus 4' 10 ¼" or about 1.5 m Equivalent to 5 pedes About 11.5" or 29.4 cm Equivalent to 12 unciae .96 inch or 2.5 cm 125 passus 120 pedes
Area
Pedes quadrans Actus quadrans Jugerum (pl. jugera) Heredium (pl. heredia) Centuria (pl. centuriae) Roman Square Foot Roman Acre Area a Century of Legionnaires covered 1 pes x 1 pes Roughly 1/3 Acre 14,400 pedes quadrans 5/8 acre or 2530 sq. m 28,800 pedes quadrans sq ft 1.25 acres / 5060 sq. m 2 Jugera 125 Acres / 506,000 sq. m 100 heredia
Volume
Hemina (pl. heminae) Sextarius (pl. sextarii) Congius (pl. congii) Amphora (pl. amphorae) Modius (pl. modii) Roman Pint Roman Quart Roman Gallon Dry or liquid measure About .57 pints or .273 liters 1.14 Pints or .546 liters 2 heminae About .85 gals or 3.2 liters 12 heminae About 6.75 gals or 25.8 liters 8 congii About 2 ½ gals 16 sextarii
Weight
Uncia Libra (pl. librae) Roman Ounce Roman Pound 1 ounce or 28g ¾ pound or 335.9g 12 unciae