Números 18:16

16 When they are a month old, you must redeem them at the redemption price set at five shekels That is, about 2 ounces or about 58 grams of silver, according to the sanctuary shekel, which weighs twenty gerahs.

16 And those that are to be redeemed of them from a month old shalt thou redeem, according to thine estimation, for the money of five shekels, after the shekel of the sanctuary (the same is twenty gerahs).