How this calculator works
The international avoirdupois pound has been defined as exactly 0.45359237 kg since the 1959 agreement on the yard and the pound. That makes one pound exactly 453.59237 g. Because grams are the smaller unit, the conversion multiplies rather than divides, and a small change in pounds produces a noticeable change in grams. The ounce row is useful because many North American recipes give a weight in pounds and ounces.
Formula
g = lb x 453.59237. lb = g / 453.59237. One pound is 16 ounces, so 1 oz = 453.59237 / 16 = 28.349523125 g.
Worked example
1 lb = 453.592 g. 0.5 lb = 226.796 g. 2 lb = 907.185 g. 10 lb = 4,535.92 g. 1 oz = 28.3495 g.
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Frequently asked questions
Why is a pound 453.59237 grams?
The 1959 international agreement defined the pound as exactly 0.45359237 kg, which is 453.59237 g. The figure is a definition, not a measurement, so it has no uncertainty.
How many grams are in an ounce?
An avoirdupois ounce is 28.349523125 g, one sixteenth of a pound. A troy ounce is different, at 31.1034768 g, and is used for precious metals.
Can I enter pounds and ounces together?
This page takes one value at a time. Convert the pounds to grams, then convert the ounces separately and add the two results, or enter the total in pounds as a decimal such as 2.5 lb.
Is a pound a force or a mass?
The pound in this conversion is the avoirdupois pound of mass. The pound-force is a different unit used for force, and it appears in pressure units such as psi. The two share a name but not a dimension.