20 grams to milligrams
20,000 mg
20 g = 20,000 mg.
milligrams
20,000mg
20 g = 20,000 mg
In short
How many milligrams is 20 grams?
20 g = 20,000 mg. 1 gram = 1,000.000000 milligrams, so the working is 20 × 1,000.000000 = 20,000.
The working
The factor below is an exact definition rather than a measurement, so nothing is approximated in the arithmetic. The only rounding on this page happens where a number is displayed.
1 gram = 1,000.000000 milligrams 20 × 1,000.000000 = 20,000
How much precision do you need?
Each row is the same answer cut at a different number of decimals, with what that choice costs you. Pick the shortest row whose error is smaller than whatever you are measuring with.
| Rounded to | Answer (mg) | Off by |
|---|---|---|
| Whole number | 20,000 | exact |
| 1 decimal | 20,000.0 | exact |
| 2 decimals | 20,000.00 | exact |
Round trip: take 20,000 mg back the other way and you land on 20.0000 g — a drift of 0.0000 g. That gap is the rounding, not the conversion.
Frequently asked questions
What is 20 grams in milligrams?
20 grams is 20,000 milligrams. 1 gram = 1,000.000000 milligrams, so the working is 20 × 1,000.000000 = 20,000.
How accurate is 20,000 mg?
Rounding to 20,000 mg and converting straight back gives 20.0000 g, a drift of 0.0000 g from the 20 you started with. The factor itself is exact; every bit of that difference comes from the rounding, not the conversion.
Nearby values
Any value at all
Grams to Milligrams Converter
Convert g to mg — and why a trailing zero is banned on a prescription.
Open the grams to milligrams converter →