mg to ml Converter
For water, 500 mg is 0.5 ml. For a 250 mg/5 ml medicine, 500 mg is 10 ml. Milligrams measure mass and milliliters measure volume, so the conversion always depends on the substance's density or concentration. Enter the amount and the mg/ml value from your label, and this converter does the division for you. The density defaults to 1000 mg/ml, which is water.
Quick answer
ml = mg divided by the density in mg/ml.
1000 mg/ml is water. For medicine, use the label concentration, like 250 mg/5 ml = 50 mg/ml.
Result
0.5 ml
What this tells you
- •ml = mg divided by the density in mg/ml.
- •Water is 1000 mg/ml, so 1000 mg of water is exactly 1 ml.
- •Liquid medicines state a concentration, like 250 mg/5 ml, which is 50 mg/ml.
- •There is no single mg to ml factor that works for every substance.
How to Use
- 1Enter the amount you want to convert.
- 2Pick the direction, mg to ml or ml to mg.
- 3Enter the density or concentration in mg/ml from the label.
- 4Read the converted amount below.
How It Works
Formula
ml = mg / density (mg/ml)Divide the milligrams by the density in mg per ml to get milliliters, or multiply milliliters by the density to get milligrams. For a syrup labeled 250 mg per 5 ml, the concentration is 50 mg/ml, so a 125 mg dose is 125 divided by 50, which is 2.5 ml.
Calculation note: values are processed in the order shown above, using the current input units.
Worked Examples
Convert 500 mg of water to ml
Water is 1000 mg/ml, so divide 500 by 1000 to get 0.5 ml.
Dose 125 mg of a 50 mg/ml medicine
Divide 125 by the 50 mg/ml concentration to get 2.5 ml.
mg to ml at Common Densities
How 500 mg converts for different substances.
| Substance | Density (mg/ml) | 500 mg in ml |
|---|---|---|
| Water | 1,000 | 0.5 ml |
| Milk | 1,030 | 0.485 ml |
| Cooking oil | 920 | 0.543 ml |
| Honey | 1,420 | 0.352 ml |
| Medicine at 250 mg/5 ml | 50 | 10 ml |
Densities are typical estimates and vary with temperature and brand. Medicine concentrations come from the label.
Common mistakes
- Assuming 1 mg always equals 0.001 ml. That is only true for water and liquids with a similar density.
- Reading a 250 mg/5 ml label as 250 mg/ml. Divide first, since that label means 50 mg per ml.
- Confusing mg with mcg on supplement labels. They differ by a factor of 1000.