“This they shall give, every one that passeth among them that are numbered, half a shekel after the shekel of the sanctuary: (a shekel is twenty gerahs:) an half shekel shall be the offering of the Lord.” Exodus 30:13
It is uncertain what exactly a shekel was, but this is the calculation of its value: the sanctuary shekel was defined as 20 gerahs. A gerah has been traditionally measured as 1/50 of an ounce, or 0.6 gram. The sanctuary shekel would then equal 0.4 of an ounce of gold (20 times 1/50 of an ounce), or 12 grams. Based on a price of $46.43 USD per gram, the approximate value of a sanctuary shekel would be $557.16, in today’s market as of the date of this writing.
An important distinction is that the standard shekel and the sanctuary shekel were two different weights. This is the reason the shekel in Exodus 30:13 is defined as a particular kind of shekel called “the shekel of the sanctuary.” This shekel was defined by weights kept in the tabernacle as the standard.
A standard shekel weighed 11.5 grams. Later, a “shekel” would also refer to a coin. God condemns the use of a false shekel: “Saying, When will the new moon be gone, that we may sell corn? and the sabbath, that we may set forth wheat, making the ephah small, and the shekel great, and falsifying the balances by deceit?” Amos 8:5
Throughout the Old Testament, the shekel was used to weigh gold (Genesis 24:22), cinnamon (Exodus 30:23), hair (2 Samuel 14:26), iron (2 Samuel 17:7), myrrh (Exodus 30:23), and food rations (Ezekiel 4:10).
Outside of the Books of Moses, only one passage mentions the sanctuary shekel. “And the shekel shall be twenty gerahs: twenty shekels, five and twenty shekels, fifteen shekels, shall be your maneh.” Ezekiel 45:12
Though not mentioned explicitly as the sanctuary shekel, the same amount is referenced. This is the same section of Scripture in which Ezekiel prophesies regarding the future Jewish temple (often referred to as the Millennial Temple).
The sanctuary shekel differed from both the shekel and the common weight. Approximations can be made to give an idea of the value of a sanctuary shekel, but uncertainty remains regarding the exact weight. The important thing is that there was a standard system of weights and measures, and God’s people paid a tax during the census under Moses. This tax was used to provide for the needs of the tabernacle and its leaders.