A grain is exactly 64.79891 milligrams.
Grains to Micrograms Converter — gr to ug
Convert Grain (gr) to Microgram (ug) using the exact conversion factor (1 grain = 64,798.91 microgram). See the formula, worked examples, and conversion table.
Grains to Micrograms 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.
Microgram is 0.000001 gram units.
Result = input x 6.479891e-5 / 1e-9.
Mass uses the kilogram as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Grains to Micrograms
Weight conversions between Grain and Microgram 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 microgram is 0.000001 gram units.
Formula
micrograms = grains × 64798.91
This factor comes from each unit's defined relationship to the category's base unit: 1 grain equals 0.00006479891 base units, and 1 microgram equals 1e-9 base units, so dividing one by the other gives the direct grain-to-microgram factor of 64798.91.
Simple example
1 gr × 64798.91 = 64,798.91 ug
1 grain = 64,798.91 micrograms.
Real-world example
50 gr × 64798.91 = 3,239,945.5 ug
50 grains = 3,239,945.5 micrograms.
Conversion table
| Grain (gr) | Microgram (ug) |
|---|---|
| 1 gr | 64,798.91 ug |
| 5 gr | 323,994.55 ug |
| 10 gr | 647,989.1 ug |
| 25 gr | 1,619,972.75 ug |
| 50 gr | 3,239,945.5 ug |
| 100 gr | 6,479,891 ug |
Reverse conversion: Microgram to Grain
1 ug × 0.00001543235835 = 0.0000154324 gr
1 microgram = 0.0000154324 grains.
grains = micrograms × 0.0000154323583529
For a page dedicated to this direction, see Microgram to Grain.
Understanding the Grain (gr)
A grain is exactly 64.79891 milligrams.
Understanding the Microgram (ug)
Microgram is 0.000001 gram units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many micrograms are in 1 grain?
1 grain equals 64,798.91 micrograms, using the exact defined conversion factor rather than an estimate.
How do I convert grain to microgram?
Multiply the grain value by 64798.91. The converter above does this instantly to whatever precision you set.
How do I convert microgram back to grain?
Use the reverse factor: 1 microgram equals 0.0000154324 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 microgram?
Microgram (ug) is a unit of mass/weight.
Is the grain to microgram conversion exact?
Yes. Both grain and microgram are defined by fixed standards rather than physical artifacts, so the factor of 64798.91 used above is exact to as many digits as you choose to display.