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Dosage Unit Conversion Calculator

This conversion calculator handles the unit math nurses and pharmacy staff use every day: mass conversions (mg, mcg, g), mg↔mL using a concentration, percent solutions to mg/mL, and mEq↔mg using molecular weight and valence.

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Educational tool, not medical advice. Verify every dose against the prescription and your institutional protocol — a licensed clinician is responsible for the final dose.

Enter values to see your result.

How to Use the Calculator

  1. Select the type of conversion you need.
  2. Enter the value to convert.
  3. For mg↔mL provide the concentration; for mEq↔mg provide the molecular weight and valence.
  4. Read the converted value and the equation used.

When to Use This Calculator

  • Converting mg, mcg, and g
  • Converting mg to mL using a drug concentration
  • Percent solution to mg/mL and mEq↔mg

Frequently Asked Questions

How do I convert mg to mL?

Divide the dose in mg by the concentration in mg/mL. You must know the concentration — mg and mL are not interchangeable without it.

How do I convert a percent solution to mg/mL?

Multiply the percent by 10. A 2% solution is 2 × 10 = 20 mg/mL, because a percent solution is grams per 100 mL.

How do I convert mEq to mg?

mg = mEq × (molecular weight ÷ valence). For example, 1 mEq of potassium (MW 39, valence 1) equals 39 mg.

References & Guidelines

  • Standard pharmacology conversion tables.