Mg to G Converter
Mg to g is a divide by 1,000 job. There are 1,000 milligrams (mg) in one gram (g), so 500 mg is 0.5 g and 1,000 mg is 1 g. Type milligrams or grams below and the other box fills in.
500 ÷ 1,000 = 0.5. Exact math, no rounding.
Paste this code into your page. It shows the converter with one plain credit link.
Common mg to g values
- 1 mg = 0.001 g
- 10 mg = 0.01 g
- 50 mg = 0.05 g
- 100 mg = 0.1 g
- 250 mg = 0.25 g
- 500 mg = 0.5 g
- 1,000 mg = 1 g
- 1,500 mg = 1.5 g
- 5,000 mg = 5 g
Number conversions only, not amounts to take. See the full printable chart.
How to convert mg to g
- Start with the number in milligrams.
- Divide by 1,000. The decimal point moves three places to the left.
- Write the unit as g.
| Milligrams (mg) | Divide by 1,000 | Grams (g) |
|---|---|---|
| 5 | 5 ÷ 1,000 | 0.005 |
| 80 | 80 ÷ 1,000 | 0.08 |
| 250 | 250 ÷ 1,000 | 0.25 |
| 2,000 | 2,000 ÷ 1,000 | 2 |
| 12,500 | 12,500 ÷ 1,000 | 12.5 |
If the answer has fewer digits than you need, add zeros in front. 5 mg turns into 0.005 g, with two zeros after the point.
How to convert g to mg
Go the other way and you multiply by 1,000. So 0.2 g × 1,000 = 200 mg, and 3 g × 1,000 = 3,000 mg. The converter above works both ways. Type in the grams box to see it.
The metric mass ladder
NIST, the US measurement lab, lists the metric units of mass in tens. Here are the steps that matter most on labels and recipes:
| Unit | Short form | Same as |
|---|---|---|
| kilogram | kg | 1,000 g |
| gram | g | 1,000 mg |
| milligram | mg | 1,000 mcg |
| microgram | mcg | 1,000 ng |
Every step is 1,000. So 1 g is 1,000 mg, and also 1,000,000 mcg. For the smaller steps, use the mg to mcg converter or read mg vs mcg. For nanograms, see ng to mcg.
Watch the capital letters
Unit symbols are case sensitive. A small "mg" is a milligram. NIST lists a capital "Mg" as a megagram, which is a metric ton, or 1,000 kg. That is a billion times more than a milligram. Most labels use the small letters, but it is worth a glance.
A gram is mass, and so is a milligram. A milliliter (mL) is volume. You cannot switch mg to mL with this converter. The page on mg vs mL explains why.
Questions
How many mg are in a gram?
There are 1,000 mg in one gram. A milligram is one thousandth of a gram.
How do you convert g to mg?
Multiply the grams by 1,000. For example, 0.75 g × 1,000 = 750 mg.
What is 1,000 mg in grams?
1,000 mg is exactly 1 g.
What is 500 mg in grams?
500 mg is 0.5 g, because 500 ÷ 1,000 = 0.5.
How many grams is 250 mg?
250 mg is 0.25 g, because 250 ÷ 1,000 = 0.25.
Sources
- The International System of Units (SI), NIST Special Publication 330, 2019 edition, Table 7 SI prefixes and Table 8 non-SI units such as the liter, National Institute of Standards and Technology (NIST), doi:10.6028/NIST.SP.330-2019, read 2026-10-04
- SI Units: Mass, National Institute of Standards and Technology (NIST), read 2026-10-04
- Metric (SI) Prefixes, National Institute of Standards and Technology (NIST), read 2026-10-04