Free Nursing Calculators
Fast, free dosage and IV calculators for nursing students and nurses. Enter your numbers and get the answer instantly — then practice the math on our free tests.
Drug Dosage Calculator
Desired ÷ Have × Quantity (the classic D/H × Q formula).
IV Drip Rate Calculator
(Volume × Drop factor) ÷ Time = gtt/min.
IV Infusion Time Calculator
Volume ÷ Rate = infusion time.
Weight-Based Dosage Calculator
Dose per kg × weight = total dose.
Tablets / Capsules Needed
Amount ordered ÷ strength available = number to give.
Practice dosage & med-math questions free
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Start free med-math practice →Nursing calculator FAQ
How do you calculate medication dosage?
Use the desired-over-have formula: Dose ordered ÷ Dose on hand × Quantity. For example, 500 mg ordered, 250 mg per tablet: 500 ÷ 250 × 1 = 2 tablets. Our free dosage calculator does this for you.
How do you calculate IV drip rate in gtt/min?
Multiply the volume (mL) by the drop factor (gtt/mL), then divide by the time in minutes: (Volume × Drop factor) ÷ Time = gtt/min. The IV drip-rate calculator above runs the formula instantly.
What is the formula for IV infusion time?
Divide the total volume by the hourly rate: Volume (mL) ÷ Rate (mL/hr) = time in hours. Multiply the decimal portion by 60 for the minutes.
How do you calculate a weight-based dose?
Multiply the prescribed dose per kilogram by the patient’s weight in kilograms: mg/kg × weight (kg) = total dose. If it is divided into several doses per day, divide the total by the number of doses.
Are these nursing calculators free?
Yes. Every calculator on this page is completely free with no signup. They are study and practice tools — always verify medication math against your facility policy and a second nurse where required.
These calculators are educational tools. Always confirm medication math against your facility policy, the order, and an independent double-check where required.