Pharmacy Calculators
Free calculators for NAPLEX prep and US pharmacy practice. Every calculation shows step-by-step workings so you can learn the method, not just get the answer.
Calculate the IV drip rate in drops per minute based on volume, infusion time, and drop factor.
mL
hours
drops/mL
Browse calculators
IV Drip Rate
Calculate intravenous drip rate in drops per minute given volume, infusion time, and the drop factor of the giving set.
Dose by Weight
Calculate weight-based doses (mg/kg or mcg/kg) for any patient. Includes total daily dose and per-dose breakdown.
Creatinine Clearance
Estimate creatinine clearance (CrCl) using the Cockcroft-Gault equation. Accepts mg/dL or µmol/L.
Infusion Rate
Calculate the pump rate in mL/hour for a weight-based infusion (e.g. dopamine, heparin, insulin, norepinephrine).
Dilution
Calculate how much stock solution to dilute to make a desired concentration and volume. USP-aligned.
Percentage Solutions
Convert between % w/v, % w/w, % v/v and absolute drug amounts. Solve any of weight, volume, or strength.
Pediatric Dosing
Weight-based pediatric dosing with Lexicomp / Micromedex cross-check. Supports mg/kg, mcg/kg, and per-day or per-dose regimens.
Unit Converter
Convert between mg, mcg, g, mL, L, kg, lb, mmol, and other common pharmacy units used in US practice and on the NAPLEX.
Want to practice NAPLEX calculations?
350+ exam-style calculation questions with detailed explanations, mapped to NABP NAPLEX competency Area 4.