Leviticus 27:4

And if it be a female - The woman, at the same age, vowed unto the Lord, might be redeemed for thirty shekels, 4. 10s. sterling, a little more than one half of the value of the man; for this obvious reason, that a woman, if employed, could not be of so much use in the service of the sanctuary as the man, and was therefore of much less value.

The relative values of the persons appear to be regulated according to an estimate of the probable value of their future work:

Ages Male Female From a month to five years of age 5 shekels 3 shekels From five years to twenty of age 20 shekels 10 shekels From forty years to sixty of age 50 shekels 30 shekels Sixty years of age and older: 15 shekels 10 shekels

As regards the shekel of the sanctuary, see Exodus 38:24 note.

27:4 Thirty shekels — Less than the man's price, because she is inferior to him both in strength and serviceableness.