Pet Medication Dose Calculator
Most pet medications are dosed by body weight. This calculator takes the animal's weight, the prescribed dose in mg per kilogram, and (for liquids) the product concentration in mg per mL, and returns the total dose in mg and the volume to draw up. The dose per kilogram is whatever your veterinarian prescribes: this tool supplies no dosing figures of its own and is not a substitute for professional veterinary advice.
Dose formula
Total dose (mg) = weight (kg) * dose (mg/kg)
Volume (mL) = total dose / concentration (mg/mL)
Daily dose (mg) = total dose * doses per day
The dose per kilogram and frequency come from the prescription. The concentration is printed on the product label.
Worked example
A 10 kg dog prescribed 5 mg/kg of a 50 mg/mL liquid, given twice daily: total dose = 10 * 5 = 50.00 mg per administration. Volume = 50 / 50 = 1.00 mL. Daily dose = 50 * 2 = 100.00 mg.
Pet medication dose: frequently asked questions
How is a weight-based pet dose calculated?
Multiply the animal's body weight in kilograms by the prescribed dose in mg per kilogram. Total dose (mg) = weight (kg) * dose (mg/kg). To convert to a liquid volume, divide the total dose by the concentration of the product in mg per mL.
Where do I find the dose per kilogram?
The dose per kilogram comes from your veterinarian's prescription or the product label for that specific animal and condition. This calculator does not supply a dose: you enter the prescribed figure. Doses vary by species, drug and indication.
Is this a substitute for veterinary advice?
No. Always follow the dose, frequency and route prescribed by a licensed veterinarian. Some drugs safe in one species are toxic in another. This tool performs the arithmetic of converting a prescribed mg/kg dose into a total dose and a volume.
Official sources
- U.S. Food and Drug Administration: Animal and Veterinary (approved animal drug oversight).
- The dose and volume relationships follow from the definitions of dose per unit mass and concentration.
Reviewed by the CalculatorHub team, edited by James Graham, 19 June 2026. See our methodology.