mg to mL Calculator — Milligrams to Millilitres Converter
Convert a mass in milligrams (mg) to a volume in millilitres (mL). Because mass and volume are fundamentally different physical quantities, the density of the liquid is required. Choose a preset substance — water, saline, ethanol, milk, oil, honey, blood — or enter a custom density.
mg
Substance
mL = mg ÷ (density × 1,000) where 1 g = 1,000 mg, 1 mL = 1 cc
- 1
Convert mg to grams
1,000 ÷ 1000 = 1 - 2
Divide by density to get volume
1 ÷ 1 = 1mL = mass (g) ÷ density (g/mL); 1 mL = 1 cc exactly
How does this calculator work?
mL = mg ÷ (density_g/mL × 1,000). For water (1 g/mL): 1,000 mg = 1 mL. For ethanol (0.789 g/mL): 1,000 mg ≈ 1.267 mL. For honey (1.42 g/mL): 1,000 mg ≈ 0.704 mL. 1 mL = 1 cc exactly. Pick a substance preset or enter a custom density to get the volume.
Formula
How this is calculated
Milligrams (mg) measure mass — the amount of matter. Millilitres (mL) measure volume — the space occupied. The link between them is density (ρ = mass ÷ volume, in g/mL). Rearranging: volume (mL) = mass (g) ÷ density (g/mL). Since the input is in mg, the first step is to divide by 1,000 to convert to grams.
For pure water at 20 °C (density = 1.000 g/mL), the numbers coincide: 1,000 mg = 1 g = 1 mL. For denser substances like honey (≈ 1.42 g/mL), the same mass occupies less volume: 1,000 mg honey ≈ 0.704 mL. For less-dense substances like ethanol (0.789 g/mL), the same mass occupies more volume: 1,000 mg ethanol ≈ 1.267 mL.
In pharmaceuticals, this calculation is used when a drug dose is specified in mg and the volume to draw from a solution is needed. Note that for solutions expressed as "mg/mL", you divide the dose (mg) by the concentration (mg/mL) rather than by density — this calculator is for when the substance's physical density (not a drug concentration) is known.
Frequently asked questions
Not exactly. Density (g/mL) is a physical property of a pure substance. mg/mL (or g/L) is a concentration, describing how much solute is dissolved in a solution. For dilute aqueous solutions, the solution's density is close to water (1 g/mL), so "mg/mL" and "mg per cc" are nearly interchangeable. For highly concentrated solutions, use the solution's actual density.
If a solution has a concentration of C mg/mL and you need a dose of D mg, the volume to administer is D ÷ C mL. For example, 500 mg dose from a 250 mg/mL solution = 500 ÷ 250 = 2 mL. This calculator handles the case where density (not concentration) is known.
1 mg of water = 0.001 mL (not 1 mL). The common confusion is that 1 gram of water ≈ 1 mL. One milligram is one-thousandth of a gram, so 1 mg water = 0.001 g ÷ 1.000 g/mL = 0.001 mL. You would need 1,000 mg (1 g) of water to get 1 mL.
Also known as
TG we-Calculate Editorial Team. (2026). mg to mL Calculator — Milligrams to Millilitres Converter [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/mg-to-ml-calculator
TG we-Calculate Editorial Team. "mg to mL Calculator — Milligrams to Millilitres Converter." TG we-Calculate. 2026. https://we-calculate.com/calculator/mg-to-ml-calculator.
TG we-Calculate Editorial Team, "mg to mL Calculator — Milligrams to Millilitres Converter," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/mg-to-ml-calculator
@misc{wecalculate_mg_to_ml_calculator, title = {mg to mL Calculator — Milligrams to Millilitres Converter}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/mg-to-ml-calculator}}, year = {2026}, note = {TG we-Calculate} }
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