Skip to main content
Veterinary DrugCalculator

mg/kg Calculator

Convert a body-weight based dose rate in mg/kg into a total dose in milligrams. Enter the patient weight and the intended dose rate, and the calculator returns the total mg to draw up. A common use is turning a labeled mg/kg dose into a mg value that you then convert to mL using the product concentration.

What this calculator does

  • Multiplies a mg/kg dose rate by the animal weight in kg.
  • Returns a total dose in mg.
  • Accepts both kg and lb inputs, and converts lb to kg first.
  • Does not verify that the dose rate is clinically appropriate.

Formula

total dose (mg) = dose rate (mg/kg) x body weight (kg)

If weight is in pounds:
body weight (kg) = weight (lb) x 0.45359237

Worked example

A 10 kg dog with a 5 mg/kg dose rate:

5 x 10 = 50 mg total

To convert this 50 mg into a volume, use the mg to mL calculator with the concentration on the product label.

Common mistakes

  • Mixing up lb and kg. Always check the unit on the scale.
  • Using a concentration value in place of the dose rate.
  • Assuming the calculated mg is clinically correct when it only reflects the numbers you entered.