Convert Grams (g) to Milligrams (mg)
Grams to milligrams is the conversion behind almost every medicine label and nutrition table: 1 g = 1000 mg. A 0.5 g dose and a 500 mg tablet are the same thing written two ways.
Formula
1 g = 1000 mg
To convert g to mg, multiply the value by 1000.
Conversion Table
| Grams (g) | Milligrams (mg) |
|---|---|
| 0.01 g | 10 mg |
| 0.1 g | 100 mg |
| 0.5 g | 500 mg |
| 1 g | 1000 mg |
| 2 g | 2000 mg |
| 3 g | 3000 mg |
| 5 g | 5000 mg |
| 10 g | 10000 mg |
| 15 g | 15000 mg |
| 20 g | 20000 mg |
| 25 g | 25000 mg |
| 50 g | 50000 mg |
| 100 g | 100000 mg |
| 250 g | 250000 mg |
| 500 g | 500000 mg |
| 1000 g | 1000000 mg |
| 2500 g | 2500000 mg |
| 5000 g | 5000000 mg |
| 10000 g | 10000000 mg |
| 50000 g | 50000000 mg |
Common g to mg Examples
- 1 g = 1000 mg
- 5 g = 5000 mg
- 10 g = 10000 mg
- 25 g = 25000 mg
- 50 g = 50000 mg
- 100 g = 100000 mg
- 500 g = 500000 mg
- 1000 g = 1000000 mg
About g to mg
Milligrams take over whenever grams get too coarse: medication doses (a typical paracetamol tablet is 500 mg = 0.5 g), caffeine content (an espresso has about 60–80 mg), and sodium on nutrition labels (the common 2 g daily sodium guideline is 2,000 mg).
Because the factor is 1000, mistakes usually come from slipping a zero — and in dosing that matters. A reliable check: the milligram value must be 1000× the gram value, so 0.25 g must read 250 mg, never 25 or 2500.
Frequently Asked Questions
How many milligrams are in half a gram?
500 mg. Multiply grams by 1000: 0.5 × 1000 = 500.
Why are medicine doses written in mg instead of g?
Doses are usually well under a gram, and whole numbers like 250 mg are harder to misread than decimals like 0.25 g — a safety convention in pharmacology.
Can I convert large numbers of g to mg at once?
Yes. The same ratio 1000 applies to any value, whether it is a fraction or millions of g.
Is there a shortcut for converting g to mg?
The shortest route is the formula itself: 1 g = 1000 mg. Memorizing this single line covers every case.
How do g and mg compare in size?
Compare them through the ratio: 1 g equals 1000 mg, which shows directly which unit represents a larger amount of Weight & Mass.
What should I check before trusting a g to mg result?
Confirm the input value, the unit direction (g to mg, not the reverse), and that the formula 1 g = 1000 mg has been applied.
Why is the conversion factor between g and mg 1000?
It comes from the official definitions of both Weight & Mass units, which are anchored to internationally agreed reference standards.
What is a quick way to estimate g to mg?
Round 1000 to one or two significant digits and multiply mentally. Use the exact factor when accuracy matters.