Q. How much is the amount of a prutah this days?

A. The value of a perutah according to the opinion of the Chazon Ish and Rav Chaim Noeh is 1/40 or .025 of a gram of silver, and according to the Masoro it is .0182 of a gram of silver (Masores Hashekel p.119, Be’er Chaim p. 207)
At today’s (Marcheshvan 5777) price of silver (about $0.55 U.S.D. per gram) it would result in $0.0125 or $0.0091, a bit more or less than a penny. (See question 1024 on this forum).

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a