To estimate how many coins of a certain
type were struck you need to know (a) how many dies were used for that
type and (b) how many coins were struck on
average from each die.
As Altamura has said
Warren Esty has published several articles which deal with formulae estimating the number of dies, and a (somewhat) simplified summary of these and other formulae can be found here:
https://www.glebecoins.org/paleos/Notes/Estimating_Die_Numbers/estimating_die_numbers.htmlWe only have rough guesses as to how many coins were produced by ancient dies, but we do know from preserved English
mint records that in
medieval times roughly 30,000 to 35,000 silver pennies were struck from the
obverse dies (with a lot less from the
reverse dies).
Ancient coins however generally have higher relief than
medieval pennies, which means they require more
work to produce, and hence more die wear, which in turn suggests that ancient
denarii dies (for example) might have struck say 10,000 to 20,000 coins
per die, with probably significantly lower figures for high relief coins like Greek tetradrachms.
Ross G.