Dosage Calculator

How Is Medication Dosage Calculated by Weight?

Weight-based dosing multiplies body weight by the prescribed amount per kilogram. The basic formula is dose in mg equals weight in kg multiplied by dosage in mg/kg. For pediatric antibiotics and common liquid formulations, see the Amoxicillin Pediatric Dosage Calculator.

Single Dose and Daily Total

Enter body weight in kilograms or pounds, the prescribed dosage in mg/kg or mcg/kg, and dosing frequency. The calculator returns a single-dose amount in milligrams and a daily total based on doses per day (once daily through every hour regimens). Always verify the result against the drug label, local formulary, and patient-specific factors such as renal function.

Liquid Medication Conversion

When a suspension concentration is known in mg/mL, liquid volume per dose equals the single dose in mg divided by concentration. For example, a 140 mg dose from a 250 mg/5 mL (50 mg/mL) suspension requires 2.8 mL. Leave concentration at zero to skip volume calculation when dispensing tablets or unknown formulations.