The base Roman unit of weight was libra (Roman pound) that contained 12 uncias. Modern estimates of the libra ranges from 322 to 329 grams with 328.9 grams an accepted figure. The base unit for coins was as that used to be 12 uncias initially and then gradually reduced to only half an uncia. Another silver coin was called denarius equal to 10 asses (from Latin dēnī - containing ten), it was later recalibrated to contain 16 asses or four sestertii. A literal meaning of each unit is given in parentheses.
libra (Roman pound, balance) | |
deunx (11⁄12 libra, less a twelfth) | |
dextans (10⁄12 libra, less a sixth) | |
dodrans (9⁄12 libra, less a fourth) | |
bes (8⁄12 libra, two of an as) | |
septunx (7⁄12 libra, seven-twelfths) | |
semis (6⁄12 libra, a half) | |
quincunx (5⁄12 libra, five-twelfths) | |
triens (4⁄12 libra, a third) | |
quadrans (1⁄4 libra, a fourth) | |
teruncius (3⁄12 libra, triple twelfth) | |
sextans (2⁄12 libra, a sixth) | |
sescuncia (1⁄8 libra, 1½ twelfths) | |
uncia (Roman ounce, a twelfth) | |
semuncia (½ uncia, half-twelfth) | |
duella (⅓ uncia, little double [sixths]) | |
sicilicus (¼ uncia, little sickle) | |
sextula (1⁄6 uncia, little sixth) | |
drachma (1⁄8 uncia, from Greek unit δραχμή) | |
semisextula (1⁄12 uncia, half-little sixth) | |
scrupulum (1⁄24 uncia, small pebble) | |
obolus (1⁄48 uncia, from Greek unit ὀβολός 'metal spit') | |
siliqua (1⁄144 uncia, carat, carob seed) | |
Units:
libra (Roman pound, balance)
/
deunx (11⁄12 libra, less a twelfth)
/
dextans (10⁄12 libra, less a sixth)
/
dodrans (9⁄12 libra, less a fourth)
/
bes (8⁄12 libra, two of an as)
/
septunx (7⁄12 libra, seven-twelfths)
/
semis (6⁄12 libra, a half)
/
quincunx (5⁄12 libra, five-twelfths)
/
triens (4⁄12 libra, a third)
/
quadrans (1⁄4 libra, a fourth)
/
teruncius (3⁄12 libra, triple twelfth)
/
sextans (2⁄12 libra, a sixth)
/
sescuncia (1⁄8 libra, 1½ twelfths)
/
uncia (Roman ounce, a twelfth)
/
semuncia (½ uncia, half-twelfth)
/
duella (⅓ uncia, little double [sixths])
/
sicilicus (¼ uncia, little sickle)
/
sextula (1⁄6 uncia, little sixth)
/
drachma (1⁄8 uncia, from Greek unit δραχμή)
/
semisextula (1⁄12 uncia, half-little sixth)
/
scrupulum (1⁄24 uncia, small pebble)
/
obolus (1⁄48 uncia, from Greek unit ὀβολός 'metal spit')
/
siliqua (1⁄144 uncia, carat, carob seed)