Convert grams to milligrams (and back) — with the full weight family, from milligrams to tonnes.
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Advanced options
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converted value
Converted
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Per-unit rate
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In grams
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All units
Common values
| 1 g | 1,000 mg |
| 0.5 g | 500 mg |
| 0.25 g | 250 mg |
| 2 g | 2,000 mg |
| 5 g | 5,000 mg |
| 0.1 g | 100 mg |
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How to use this tool
1
Enter a valueType any amount (fractions and decimals allowed).
2
Pick the unitsChoose the From and To units, or tap Swap to reverse the conversion.
3
Read every unit at onceThe result, the per-unit rate and the full unit family are shown together, live as you type.
4
Check the common valuesThe reference table covers the values people look up most, so you can sanity-check at a glance.
Formula & worked example
Milligrams = grams x 1,000. Exactly 1 g = 1,000 mg.
2 g = 2,000 mg. A 0.5 g dose is 500 mg, and 0.25 g is 250 mg.
Limitations — read this before you rely on it
Grams and milligrams measure mass. For medicines, always double-check the unit on the label — a 10x error between mg and g is a common and serious mistake.
Frequently asked questions
1,000 mg.
1 g = 1,000 mg.
2,000 mg.
Yes, exactly.
Multiply grams by 1,000.