Free resources · Practice
Dosage calculation practice
Seven calculation skills, unlimited problems, graded instantly. Every solution shows the setup, how the units cancel and why the answer is rounded the way it is — because the method is the thing worth learning.
These are practice problems for exam preparation. Every number in them is generated by CARE for teaching purposes — nothing here is a real order and nothing here is a clinical dosing tool. Do not use this page to work out a dose for a real patient: use your facility's policy, the actual order, and an independent double-check where your policy requires one.
Worked example: learn the method
Ungraded teaching example with different numbers from the practice exercise. For study only, not clinical use.
An order reads 200 mg. The medication is supplied as 200 mg per 5 mL. How many millilitres supply the ordered dose?
(Desired dose ÷ dose on hand) × volume on hand = millilitres to give
- Set up the ratio: 200 mg ÷ 200 mg = 1
- Multiply by the supplied volume: 1 × 5 mL = 5 mL
- Units cancel: mg ÷ mg cancels, leaving mL — the unit you were asked for.
Example result: 5 mL. Round to the nearest tenth of a millilitre.
Common mistake to avoid: Keep the supplied volume in the ratio. A label expressed per several millilitres is not a strength per one millilitre.
Printable dosage formulas · Unit conversions
Choose a skill
Tablets and capsules
How many tablets to give when the ordered dose and the tablet strength differ.
Example: An order reads 750 mg. The medication is available as 500 mg tablets. How many tablets supply the ordered dose?
Practised by: RN · PN · MA
Practise this skillLiquid oral doses
How many millilitres of a liquid medication supply the ordered dose.
Example: An order reads 125 mg. The medication is supplied as 125 mg per 15 mL. How many millilitres supply the ordered dose?
Practised by: RN · PN · MA
Practise this skillMetric conversions
Converting between grams, milligrams and micrograms before you calculate.
Example: Convert 1000 mcg to mg.
Practised by: RN · PN · MA
Practise this skillWeight-based doses
Doses ordered per kilogram, including converting a weight given in pounds.
Example: A dose is ordered at 2 mg/kg. The person weighs 188 lb. What total dose does that order call for?
Practised by: RN · PN
Practise this skillIV pump rate (mL/hr)
Setting an infusion pump when a volume must run over a given time.
Example: 1000 mL is to infuse over 4 hours. What rate should the pump be set to?
Practised by: RN · PN
Practise this skillDrip rate (gtt/min)
Counting drops per minute for gravity tubing with a known drop factor.
Example: 50 mL is to infuse over 240 minutes using tubing with a drop factor of 60 gtt/mL. What is the drip rate?
Practised by: RN · PN
Practise this skillInfusion time
How long an infusion will take at a set rate.
Example: 900 mL is infusing at 150 mL/hr. How many hours will the infusion take?
Practised by: RN · PN
Practise this skillPractising for a specific exam?
Dosage questions appear inside real exam practice too, mixed with everything else and scored the way the rest of your practice is. Our NCLEX-RN and NCLEX-PN banks carry medication-calculation items in context, with rationales.