Milligrams to Grams
Type a value in either box to convert between milligrams and grams. The factor is 0.001.
| Milligrams | Grams |
|---|---|
| 1 mg | 0.001 g |
| 2 mg | 0.002 g |
| 3 mg | 0.003 g |
| 5 mg | 0.005 g |
| 10 mg | 0.01 g |
| 25 mg | 0.025 g |
| 50 mg | 0.05 g |
| 100 mg | 0.1 g |
How to use
- Enter a value in the Milligrams field.
- The Grams figure appears immediately — no button to press.
- Typing in the Grams field converts back to Milligrams the same way.
- Use the reference table for the values that come up most often.
Milligrams to Grams formula
Converting milligrams to grams is a single multiplication by 0.001.
g = mg × 0.001
Put another way, one milligram is exactly 1/1,000 of a gram.
Why this factor: the milligram and the gram are both defined against the kilogram, so dividing one definition by the other gives 0.001 directly. Both definitions are set out in full below.
To go the other way, divide by 0.001 — or use the Grams to Milligrams converter, which is the same calculation reversed.
Worked example
Start with 25 mg. Multiply by 0.001 to get 0.025 g.
25 mg × 0.001 = 0.025 g
The converter above does this for any value you type, in either direction.
What is a milligram?
A milligram is one thousandth of a gram — the standard unit for drug doses and micronutrients.
Definition: Exactly 1×10⁻⁶ kilogram by SI prefix definition.
Where it is used: Medication dosages, vitamin and mineral content, and analytical chemistry.
What is a gram?
A gram is one thousandth of a kilogram, the everyday unit for food and small-object mass.
Definition: Exactly 0.001 kilogram by SI prefix definition.
Where it is used: Nutrition labels, recipes, postal rates, and laboratory weighing.
Milligrams vs Grams
The milligram and the gram belong to the same family of units, so converting between them is usually a matter of shifting a decimal point or applying a small whole-number factor.
Frequently asked questions
How many grams are in a milligram?
One milligram equals 0.001 grams.
What is the formula to convert milligrams to grams?
Multiply the number of milligrams by 0.001. To reverse it, divide by 0.001 instead.
How do I convert grams back to milligrams?
Divide by 0.001, which is the same as multiplying by 1000.
How many grams are in 10 milligrams?
10 mg works out to 0.01 g.
How is the milligram defined?
Exactly 1×10⁻⁶ kilogram by SI prefix definition.