How do I find the concentration of my medication?

The concentration is listed on the medication label. It's typically expressed as mg/mL (e.g., 100mg/mL) or mg per volume (e.g., 250mg/5mL). For the latter, divide by the volume to get mg/mL: 250mg/5mL = 50mg/mL.

Why can't I just use water density to convert mg to mL?

Using water density (1g/mL) only works for pure water. Medications have different densities and, more importantly, contain varying amounts of active ingredient per volume. The concentration tells you exactly how much drug is in each mL.

What if my medication concentration is in mg/5mL format?

Divide the mg by 5 to get the mg/mL concentration. For example, if your medication is 250mg/5mL, the concentration is 250÷5 = 50mg/mL. Enter 50 in the concentration field.

General Dose Math

mg to mL Conversion Calculator

Convert between milligrams (mg) and milliliters (mL) using medication concentration. Essential for liquid medication dosing.

mg ↔ mL Calculator

Convert between milligrams (mg) and milliliters (mL) using medication concentration. Essential for liquid medication dosing.

Conversion Type

Dose AmountThe dose you need to give (in mg)

ConcentrationMedication strength (e.g., 100mg/mL)

mg/mL

This calculator provides mathematical estimates only. Always verify dosages with a qualified healthcare professional before administering any medication.

Important Disclaimer

This calculator provides estimates for informational purposes only. Always consult a healthcare professional before making medical decisions.

About This Calculator

Converting between milligrams (mg) and milliliters (mL) is one of the most common calculations in medication administration. This calculator uses the medication's concentration to accurately convert between dose (mg) and volume (mL). Unlike density-based conversions, this method accounts for the actual drug content in the solution.

How It Works

Enter the dose you need to give in milligrams and the concentration of your medication (found on the label, e.g., '100mg/mL' or '250mg/5mL'). The calculator uses the formula: Volume (mL) = Dose (mg) ÷ Concentration (mg/mL). For concentrations given as mg/5mL, first convert to mg/mL by dividing by 5.

Frequently Asked Questions

Milligrams (mg) measure the mass or weight of a substance (the actual drug content), while milliliters (mL) measure volume (the amount of liquid). To convert between them, you need to know the concentration of the medication.

Clinical Review

Dr. Igor I. Bussel, MD

Board-Certified Ophthalmologist

Dr. Igor I. Bussel is a board-certified ophthalmologist and fellowship-trained surgeon affiliated with the University of California, Irvine (UCI), the Gavin Herbert Eye Institute, and the UCI School of Medicine.

Last Updated: 2025-01-05

Sources & Guidelines

Drug Calculations for Nurses - A Step-by-Step Approach

Medically Reviewed

Evidence-Based

Updated 2025-01-05

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References

Drug Calculations for Nurses - A Step-by-Step Approach

Reviewed by: Clinical Review Team (PharmD, RPh)

Last updated: 2025-01-05