A grain is exactly 64.79891 milligrams.
Grains to Grams Converter — gr to g
Convert Grain (gr) to Gram (g) using the exact conversion factor (1 grain = 0.06479891 gram). See the formula, worked examples, conversion table, history, and common uses.
Grains to Grams converter
Converter
Mass/Weight Converter
Convert SI mass, imperial weight, jewelry, atomic, and astronomy mass units.
Context values
Some unit families need one extra value for a physically accurate result.
A gram is one thousandth of a kilogram.
Result = input x 6.479891e-5 / 0.001.
Mass uses the kilogram as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Grains to Grams
Weight conversions between Grain and Gram come up constantly in everyday commerce, shipping, and cooking, since US packaging is usually labeled in pounds while most of the rest of the world uses kilograms. Specifically: A grain is exactly 64.79891 milligrams, and a gram is one thousandth of a kilogram.
Formula
grams = grains × 0.06479891
This factor comes from each unit's defined relationship to the category's base unit: 1 grain equals 0.00006479891 base units, and 1 gram equals 0.001 base units, so dividing one by the other gives the direct grain-to-gram factor of 0.06479891.
Simple example
1 gr × 0.06479891 = 0.06479891 g
1 grain = 0.06479891 grams.
Real-world example
50 gr × 0.06479891 = 3.2399455 g
50 grains = 3.2399455 grams.
Conversion table
| Grain (gr) | Gram (g) |
|---|---|
| 1 gr | 0.06479891 g |
| 5 gr | 0.32399455 g |
| 10 gr | 0.6479891 g |
| 25 gr | 1.61997275 g |
| 50 gr | 3.2399455 g |
| 100 gr | 6.479891 g |
Reverse conversion: Gram to Grain
0.06479891 g × 15.43235835 = 1 gr
0.06479891 grams = 1 grains.
grains = grams × 15.4323583529
For a page dedicated to this direction, see Gram to Grain.
Understanding the Grain (gr)
A grain is exactly 64.79891 milligrams.
Understanding the Gram
Gram (g) measures mass. A gram is one-thousandth of a kilogram, the SI base unit of mass. It is classified as a SI derived (metric prefix) unit.
Where it's used: Standard small-mass unit worldwide
Uses of the Gram today
- Cooking and nutrition labeling worldwide (including in the US, alongside ounces)
- Precious metal and small-item weighing
- Scientific and laboratory measurement
History of the Gram
Originally defined in 1795 as the mass of one cubic centimeter of water, the gram follows directly from the kilogram (1/1000 of it) under the modern SI system, inheriting the kilogram's various historical and current definitions.
Historical origin. Gram was not the invention of a single named person; it developed through the process described above.
Gram — sources
- BIPM — The kilogram (SI base unit) — Basis for the gram as 1/1000 of the kilogram.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many grams are in 1 grain?
1 grain equals 0.06479891 grams, using the exact defined conversion factor rather than an estimate.
How do I convert grain to gram?
Multiply the grain value by 0.06479891. The converter above does this instantly to whatever precision you set.
How do I convert gram back to grain?
Use the reverse factor: 1 gram equals 15.43235835 grains. You can also use the swap control in the converter above to flip the direction instantly.
What is a grain?
Grain (gr) is a unit of mass/weight.
What is a gram?
Gram (g) measures mass. A gram is one-thousandth of a kilogram, the SI base unit of mass. It is classified as a SI derived (metric prefix) unit.
Is the grain to gram conversion exact?
Yes. Both grain and gram are defined by fixed standards rather than physical artifacts, so the factor of 0.06479891 used above is exact to as many digits as you choose to display.