mg to g Conversion Chart (and g to mg) for Nursing
Shows the work. Every example is computed with the formula and numbered steps. For study and exam practice, not for patient care.
Antibiotic orders are often in grams while labels and syringes are in milligrams, or the other way round. One gram is 1,000 milligrams.
Rule: 1 g = 1,000 mg. To go from mg to g, divide by 1,000. To go from g to mg, multiply by 1,000.
For any other amount, use the Unit converter calculator: it shows the factor and each step.
mg to g
| mg | g |
|---|---|
| 1 | 0.001 |
| 5 | 0.005 |
| 10 | 0.01 |
| 50 | 0.05 |
| 100 | 0.1 |
| 125 | 0.125 |
| 250 | 0.25 |
| 300 | 0.3 |
| 325 | 0.325 |
| 500 | 0.5 |
| 650 | 0.65 |
| 750 | 0.75 |
| 1,000 | 1 |
| 1,500 | 1.5 |
| 2,000 | 2 |
g to mg
| g | mg |
|---|---|
| 0.01 | 10 |
| 0.05 | 50 |
| 0.1 | 100 |
| 0.125 | 125 |
| 0.25 | 250 |
| 0.5 | 500 |
| 0.75 | 750 |
| 1 | 1,000 |
| 1.5 | 1,500 |
| 2 | 2,000 |
| 2.5 | 2,500 |
| 3 | 3,000 |
| 4 | 4,000 |
| 5 | 5,000 |
Good to know
- Write a leading zero for amounts under 1 (0.5 g), never a trailing zero (2 g, not 2.0 g).
- Convert to the label's unit first, then calculate the volume or tablet count.
Worked example
Metoprolol tartrate 100 mg PO is ordered. Express the dose in grams.
- Value
- 100 mg
- To
- g
Formula Multiply or divide by the conversion factor.
- 1 g = 1,000 mg, so divide by 1,000.
- 100 ÷ 1,000 = 0.1 g.
- 0.1 g is exact, so no rounding is needed.
Answer 0.1 g
FAQ
How many mg are in 1 g?
1,000.
How do you convert mg to g?
Divide the milligrams by 1,000, which moves the decimal point three places to the left.
Terms on this page: Leading and trailing zeros, Concentration
Sources
- List of Error-Prone Abbreviations, Symbols, and Dose Designations — Institute for Safe Medication Practices (ISMP)
- Clinical Calculations: With Applications to General and Specialty Areas (Kee, Marshall, et al.) — Elsevier
- Calculate with Confidence (Morris) — Elsevier