ROMAN UNIT

MODERN APPROXIMATION

MODERN ENGLISH / METRIC ROMAN UNITS

Mille passus

Roman Mile

1618 yds / 1480 m Equivalent to 1000 passus

Passus

Roman Yard

4' 10 ¼" or about 1.5 m Equivalent to 5 pedes

Pes (pl. pedes)

Roman Foot

About 11.5" or 29.4 cm Equivalent to 12 unciae

Uncia (pl. unciae)

Roman Inch

.96 inch or 2.5 cm

Stadium (pl. stadia)

Roman Nautical Unit

125 passus

Actus

Roman Land Unit

120 pedes

Pedes quadrans

Roman Square Foot

1 pes x 1 pes

Actus quadrans

-

Roughly 1/3 Acre 14,400 pedes quadrans

Jugerum (pl. jugera)

Roman Acre

5/8 acre or 2530 sq. m 28,800 pedes quadrans sq ft

Heredium (pl. heredia)

-

1.25 acres / 5060 sq. m 2 Jugera

Centuria (pl. centuriae)

Area a Century of Legionnaires covered

125 Acres / 506,000 sq. m 100 heredia

Hemina (pl. heminae)

Roman Pint

About .57 pints or .273 liters

Sextarius (pl. sextarii)

Roman Quart

1.14 Pints or .546 liters  2 heminae

Congius (pl. congii)

Roman Gallon

About .85 gals or 3.2 liters 12 heminae

Amphora (pl. amphorae)

-

About 6.75 gals or 25.8 liters 8 congii

Modius (pl. modii)

Dry or liquid measure

About 2 ½ gals 16 sextarii

Uncia

Roman Ounce

1 ounce or 28g

Libra (pl. librae)

Roman Pound

¾ pound or 335.9g 12 unciae