MG to Grams Converter
Convert milligrams to grams — a thousand to the gram, the conversion of doses and supplements. Results update as you type; exact factors shown.
One milligram is 0.001 grams — see the exact factor, not a rounded rule of thumb.
How the mg to grams converter works
Mass converts through the kilogram. The avoirdupois pound has been exactly 0.45359237 kg since 1959, so an ounce is 28.349523125 g and a stone (14 lb) is 6.35029318 kg. A US short ton is 2,000 lb; an imperial long ton is 2,240 lb; a metric tonne is 1,000 kg.
Australia is fully metric under the National Measurement Act 1960; imperial units appear only in trade with the US and in older documents.
Common mass conversions
| From | To | Units |
|---|---|---|
| 1 mg | 0.001 g | milligram to grams |
| 10 mg | 0.01 g | milligrams to grams |
| 50 mg | 0.05 g | milligrams to grams |
| 100 mg | 0.1 g | milligrams to grams |
| 250 mg | 0.25 g | milligrams to grams |
| 500 mg | 0.5 g | milligrams to grams |
| 750 mg | 0.75 g | milligrams to grams |
| 1,000 mg | 1 g | milligrams to grams |
| 2,000 mg | 2 g | milligrams to grams |
| 5,000 mg | 5 g | milligrams to grams |
| 10,000 mg | 10 g | milligrams to grams |
| 100,000 mg | 100 g | milligrams to grams |
Units in this converter and their exact factors
| Unit | Symbol | One unit in kilograms |
|---|---|---|
| milligram | mg | 0.000001 kilogram |
| gram | g | 0.001 kilogram |
| kilogram | kg | 1 kilogram |
| tonne (metric ton) | t | 1,000 kilogram |
| ounce | oz | 0.0283495231 kilogram |
| pound | lb | 0.45359237 kilogram |
| stone | st | 6.35029318 kilogram |
| US ton (short) | US ton | 907.18474 kilogram |
| imperial ton (long) | long ton | 1,016.0469088 kilogram |
FAQFrequently asked questions about mass conversion
How many mg in a gram?
A thousand.
What is 500 mg in grams?
0.5 g.
Why are doses in mg?
Because active ingredients are small; a 500 mg tablet is half a gram of medicine plus filler.
What is a microgram?
A thousandth of a milligram — used for vitamins D and B12.
Where these figures come from
- BIPM — The International System of Units (SI Brochure, 9th edition) — definitions of the base and derived units.
- NIST Special Publication 811 — Guide for the Use of the International System of Units — the exact conversion factors used here.
- National Measurement Institute (NMI) — Australia's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.