mg/kg to mL Calculator
Convert an ordered dose in mg/kg into a measurable volume in mL using medication concentration (mg/mL).
Enter the ordered dose per kilogram. Commas accepted if needed.
Use kilograms (kg). Double-check paediatric weights.
Concentration in mg per mL. Leave blank if using the label helper below.
How mg/kg to mL Conversion Works
A mg/kg order means the dose depends on patient weight. First, multiply the ordered dose (mg/kg) by the patient’s weight (kg) to calculate the total dose in mg.
Once you know the total mg, you convert it to a measurable volume by dividing by the medication concentration (mg/mL). If the label is written as “mg per X mL” (e.g., 250 mg per 5 mL), convert it to mg/mL first by dividing mg by mL.
Formula
Worked Examples
Example 1: Order 10 mg/kg. Weight 70 kg. Concentration 50 mg/mL. How many mL?
mL = 700 ÷ 50 = 14 mL
Total dose = 10 mg/kg × 70 kg = 700 mg
Volume = 700 mg ÷ 50 mg/mL = 14 mL
Example 2: Order 15 mg/kg. Weight 18 kg. Label 250 mg in 5 mL. How many mL?
Total mg = 15 × 18 = 270 mg
mL = 270 ÷ 50 = 5.4 mL
Concentration = 250 mg ÷ 5 mL = 50 mg/mL
Total dose = 15 mg/kg × 18 kg = 270 mg
Volume = 270 mg ÷ 50 mg/mL = 5.4 mL
Example 3: Order 2.5 mg/kg. Weight 18 kg. Concentration 40 mg/mL. How many mL?
mL = 45 ÷ 40 = 1.125 mL
Rounded (2 decimals) = 1.13 mL
Total dose = 2.5 mg/kg × 18 kg = 45 mg
Volume = 45 mg ÷ 40 mg/mL = 1.125 mL
When This Calculator Is Used
- •Weight-based dosing (mg/kg), especially paediatrics
- •Converting a total calculated dose (mg) to a measurable volume (mL)
- •Converting “mg per X mL” labels into mg/mL before calculation
- •Medication preparation checks and double-checking arithmetic
Clinical safety note: Always confirm the ordered dose, patient weight (kg), product concentration, and local protocols. This calculator supports calculation checking but does not replace clinical judgement.
Related Calculators
Frequently Asked Questions
Clinical reminder: Always follow local protocols and consult medication information sheets. These examples are for calculation practice only.
References & Sources
This calculator follows standard medication calculation methods used in nursing and prescribing education, including weight-based dosing (mg/kg) and dose-to-volume conversion (mg/mL).