Milligrams = grams × 1,000
Milli represents one thousandth. A milligram is one thousandth of a gram, so each gram contains exactly one thousand milligrams.
Grams to Milligrams Converter
1 gram equals exactly 1,000 milligrams. Multiply grams by 1,000 to convert g to mg.
This page converts units of mass only. It does not provide medication, supplement or dosing advice.
Grams to Milligrams Converter
Enter a non-negative gram amount.
Grams to Milligrams Converter
The conversion factor is fixed. Displayed results are rounded for readability.
Use the calculator for any amount. The chart provides quick reference values.
Swipe horizontally to view every column
| Grams | Milligrams (mg) |
|---|---|
| 0.001 g | 1 mg |
| 0.01 g | 10 mg |
| 0.1 g | 100 mg |
| 0.5 g | 500 mg |
| 1 g | 1,000 mg |
| 2 g | 2,000 mg |
| 5 g | 5,000 mg |
| 10 g | 10,000 mg |
| 25 g | 25,000 mg |
The arithmetic is simple, but unit errors can be serious when small quantities are involved. Always check that the source value is truly in grams before multiplying.
This calculator is intended for general unit conversion. Product labels, laboratory protocols and medical instructions should be followed exactly and checked by an appropriate professional.
Worked g to mg examples
These examples show the formula with common amounts.
0.5 grams to milligrams
0.5 × 1,000 = 500 mg.
2 grams to milligrams
2 grams is exactly 2,000 milligrams.
25 grams to milligrams
25 × 1,000 = 25,000 mg.
Method and source
How this conversion was checked
The conversion factor is fixed. Displayed results are rounded for readability. The calculator validates the input and applies the formula shown on this page.
Primary reference: National Institute of Standards and Technology
Conversion type: Fixed mass-to-mass factor
How many milligrams are in one gram?
There are exactly 1,000 milligrams in one gram.
How do I convert grams to milligrams?
Multiply the gram amount by 1,000.
Is 0.5 grams equal to 500 milligrams?
Yes. Half a gram is exactly 500 milligrams.
Is mg the same as mL?
No. Milligrams measure mass while milliliters measure volume.
Can this calculator be used for medication dosing?
It converts units only and does not replace a prescription, product label or professional dosing advice.
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