If the weight of an anvil is marked on it, there are four or more possible methods. The most common on old English and some European anvils is the Old English Hundredweight system
of hundredweights (112 pounds), quarter hundredweights (28 pounds) and pounds. More modern English anvils may be marked in whole and fractional hundred weights such as "1¼ Cwt". Many European anvils are marked in kilograms but Swedish export anvils were once marked in pounds. Old German anvils were marked in the "pfund" (486 to 510 grams)
. Forged Ameican anvils are marked in pounds and old cast American anvils in tens (18 = ~180 pounds). It is highly possible that other traditional units were used in other parts of the world if they manufactured anvils.