mg to mL Calculator

Convert milligrams to milliliters based on density. Essential for liquid medications and solutions.

mg
Do you know the density?
Volume
0.5000 mL
Mass
500 mg
Density
1.0000 g/mL
Volume
0.5000 mL

For water, 1 mL = 1 g = 1000 mg.

Converting mg to mL

Milligrams (mg) measure mass while milliliters (mL) measure volume. To convert between them, you need to know the density or concentration.

For pure substances

Volume (mL)=Mass (mg)Density (g/mL)×1000\text{Volume (mL)} = \frac{\text{Mass (mg)}}{\text{Density (g/mL)} \times 1000}

For liquid medications

Volume (mL)=Dose (mg)Concentration (mg/mL)\text{Volume (mL)} = \frac{\text{Dose (mg)}}{\text{Concentration (mg/mL)}}

Water conversion

For water at room temperature:

  • Density = 1 g/mL
  • 1 mL = 1 g = 1000 mg

So for water: mg ÷ 1000 = mL

Common medication concentrations

MedicationCommon Concentration
Acetaminophen liquid160 mg/5 mL (32 mg/mL)
Ibuprofen liquid100 mg/5 mL (20 mg/mL)
Amoxicillin250 mg/5 mL (50 mg/mL)
Benadryl12.5 mg/5 mL (2.5 mg/mL)

Example calculation

Problem: How many mL of liquid ibuprofen (100 mg/5 mL) for a 150 mg dose?

Concentration=100 mg5 mL=20 mg/mLVolume=150 mg20 mg/mL=7.5 mL\begin{aligned} \text{Concentration} &= \frac{100 \text{ mg}}{5 \text{ mL}} = 20 \text{ mg/mL} \\[0.5em] \text{Volume} &= \frac{150 \text{ mg}}{20 \text{ mg/mL}} = 7.5 \text{ mL} \end{aligned}

Important notes

  • Always check medication labels for concentration
  • Different formulations of the same drug may have different concentrations
  • Consult a healthcare provider for dosing questions
  • Use proper measuring devices (not household spoons)