Gram (g)

Definition

One thousandth of a kilogram (10⁻³ kg) in the SI.

History

The gram was the original base of the metric system set out in 1795, defined as the mass of one cubic centimeter of water at the melting point of ice, before the larger kilogram was chosen as the SI base unit. It is now simply one thousandth of a kilogram.

Where it is used

Grams are the everyday metric unit for small masses: recipe ingredients, nutrition labels, medicine doses and postage.

Typical uses include recipe and food weights, nutrition labels, postage.

Conversion pages

These pages convert gram to or from another unit in weight.

• Gram to ounce

Other Weight units

• Kilogram (kg)
• Pound (lb)
• Ounce (oz)
• Stone (st)
• Milligram (mg)
• Microgram (mcg)
• Tonne (t)

Sources

• BIPM SI BIPM, The International System of Units (SI), 9th ed. (2019) · Dataset reviewed Nov 11, 2026