To convert milligrams to grams, divide by 1000. So 500 mg = 0.5 g and 1000 mg = 1 g. This is exact - the SI prefix "milli" means 1/1000 by definition.
- Exact: 1 mg = 0.001 g - defined by the SI prefix "milli" = 1/1000.
- 500 mg = 0.5 g. 1000 mg = 1 g. 250 mg = 0.25 g.
- Move the decimal three places left to convert mg to g.
- Common medication doses: ibuprofen 200–400 mg, paracetamol 500–1000 mg.
How to Use This Converter
Type any milligrams value in the mg field and the grams result appears instantly. You can also type in the g field to convert back to mg. The conversion is exact - divide by 1000.
How Do You Convert Milligrams to Grams?
Divide milligrams by 1000. The SI prefix "milli" means 1/1000, so 1 milligram = 0.001 gram by definition. Move the decimal point three places to the left.
$$\text{g} = \text{mg} \div 1000$$
Worked examples: 100 mg = 0.1 g. 200 mg = 0.2 g. 250 mg = 0.25 g. 400 mg = 0.4 g. 500 mg = 0.5 g. 1000 mg = 1 g. 2000 mg = 2 g.
How Do You Convert Grams to Milligrams?
Multiply grams by 1000. See the dedicated grams to milligrams converter for a grams-first reference table.
$$\text{mg} = \text{g} \times 1000$$
Worked examples: 0.5 g = 500 mg. 1 g = 1000 mg. 2.5 g = 2500 mg.
Milligrams to Grams Reference Table
Common medication doses and laboratory measurements converted from mg to grams:
| Milligrams (mg) | Grams (g) | Common context |
|---|---|---|
| 50 mg | 0.05 g | Low-dose aspirin |
| 100 mg | 0.1 g | - |
| 200 mg | 0.2 g | Ibuprofen tablet |
| 250 mg | 0.25 g | Amoxicillin 250 mg |
| 400 mg | 0.4 g | Ibuprofen standard dose |
| 500 mg | 0.5 g | Paracetamol tablet |
| 600 mg | 0.6 g | Ibuprofen max single dose |
| 1000 mg | 1 g | Paracetamol max single dose |
| 1500 mg | 1.5 g | - |
| 2000 mg | 2 g | Metformin 1000 mg twice daily |
| 4000 mg | 4 g | Paracetamol max daily dose |
When Do You Need to Convert mg to Grams?
- Medication dosing - drug doses are in mg; pharmacy scales and dispensing records may require grams.
- Nutritional labels - vitamins and minerals are listed in mg; daily intake totals may be reported in grams.
- Chemistry and lab - reagent quantities in milligrams need to be expressed in grams for formula calculations.
- Precious metals and gems - small weights in mg need conversion to grams for weighing and valuation.
Frequently Asked Questions
How many grams is 500 mg?
500 mg = 0.5 g. Divide 500 by 1000. This is the weight of a standard paracetamol or acetaminophen tablet.
How do you convert mg to grams?
Divide by 1000, or move the decimal three places left. For 750 mg: 750 ÷ 1000 = 0.75 g. Exact - no rounding needed.
How many grams is 1000 mg?
1000 mg = 1 g exactly. This is the most common anchor point: 1 gram = 1000 milligrams by definition.