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Milligrams to Grams

Convert milligrams (mg) to grams (g). 1 mg = 0.001 g (and 1 g = 1000 mg). It all runs locally in your browser.

=
Grams (g) 0.001

Milligrams to Grams table

MilligramsGrams
0.5 mg0.0005 g
1 mg0.001 g
2 mg0.002 g
3 mg0.003 g
5 mg0.005 g
10 mg0.01 g
25 mg0.025 g
50 mg0.05 g
100 mg0.1 g

Where this conversion shows up

Medicine, supplements and nutrition, where doses are printed in milligrams but totals get discussed in grams — and where a factor-of-1000 slip is the classic dangerous error.

Worked example

A strong coffee has about 95 mg of caffeine, so the widely cited 400 mg daily ceiling is 0.4 g, or roughly four cups. A 500 mg paracetamol tablet is half a gram.

Rounding and precision

No rounding needed — it is a straight shift of the decimal point three places. The risk here is not precision, it is misreading mg for g on a label or a prescription.

How to convert

To convert milligrams to grams, multiply by 0.001. Need other units? Use the full Unit Converter.

FAQ

How many grams in a milligram?

1 milligram equals 0.001 grams (g).

How do I convert milligrams to grams?

Multiply the milligrams value by 0.001. For example, 5 mg = 0.005 g.

How many mg in a gram?

1,000 mg. To convert milligrams to grams, divide by 1,000; to go the other way, multiply by 1,000.

Is 500mg the same as 0.5g?

Yes, exactly. They are two ways of writing the same quantity — which is why labels sometimes use one and packaging the other.

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