How to Calculate a Veterinary Drug Dose
Step-by-step explanation of the standard veterinary dose calculation: dose rate × body weight = total dose, then total dose ÷ concentration = volume.
A veterinary dose calculation has two steps. First, a dose rate expressed per kilogram of body weight is multiplied by the animal's body weight in kilograms to obtain the total dose. Second, the total dose is divided by the concentration of the product on hand to obtain the volume to draw up.
Step 1 — total dose total dose (mg) = dose rate (mg/kg) × body weight (kg)
Step 2 — volume volume (mL) = total dose (mg) ÷ concentration (mg/mL)
Units must match. If the dose rate is given in mg/kg but the concentration is in mcg/mL, convert one of them first so both use the same base unit (mg or mcg).
This is a mathematical procedure. It does not tell you whether a given drug is appropriate for a given patient, whether the dose rate you selected is correct, or whether the route is appropriate. Those decisions require veterinary judgment and a current, verified reference.
Educational use only
Educational calculation only. This result does not determine whether the medication or dose is appropriate for an individual animal. Verify clinical decisions with a qualified veterinarian.