Conquer the most challenging part of the GPhC exam with our comprehensive calculation practice system. Learn proven methods, avoid common mistakes, and build speed and accuracy.
Master weight-based dosing, pediatric and geriatric calculations, and dose adjustments for special populations.
Practice percentage strength, parts per million, molarity, and complex dilution problems with multiple steps.
Learn profit and loss calculations, insurance reimbursements, markup and discount problems, and cost analysis.
Calculate drip rates, infusion times, and pump settings for various IV medications and fluids.
Solve complex mixture problems using alligation methods, including alcohol dilutions and ointment preparations.
Master trace concentration calculations including water quality, contamination levels, and analytical chemistry.
Practice converting between metric, imperial, and pharmaceutical units including temperature and pressure conversions.
Calculate bioavailability, bioequivalence, clearance, half-life, and steady-state concentrations.
Start with clear explanations of the underlying principles and when to use each calculation method.
Follow step-by-step worked examples that show you exactly how to approach each problem type.
Work through problems with hints and immediate feedback to reinforce your understanding.
Practice under time pressure to develop the speed and confidence needed for exam success.
"A patient weighing 70 kg requires a loading dose of digoxin at 10 micrograms/kg. The injection available contains 250 micrograms/ml. What volume should be administered?"
Total dose = 70 kg × 10 micrograms/kg = 700 micrograms
Volume = 700 micrograms ÷ 250 micrograms/ml = 2.8 ml
Always check units match throughout your calculation
First find total dose, then calculate volume needed
2.8 ml is a reasonable injection volume
Dose required ÷ Concentration = Volume
Mixing up mg and micrograms, or ml and L can lead to dangerous dosing errors.
Prevention:
Always write out units in every step and double-check conversions.
Misplacing decimal points can result in 10x or 100x dosing errors.
Prevention:
Use leading zeros (0.5 not .5) and avoid trailing zeros (5 not 5.0).
Using the wrong formula or mixing up numerator and denominator.
Prevention:
Memorize key formulas and practice identifying which one to use.
Dimensional Analysis
Set up calculations so units cancel out properly.
Estimation
Round numbers to check if your answer makes sense.
Show Your Work
Write out each step to catch errors and get partial credit.
Dose = (Weight × Dose per kg)
Volume = Dose Required ÷ Concentration
% w/v = (Weight of solute ÷ Volume of solution) × 100
C₁V₁ = C₂V₂
ppm = (mg of solute ÷ L of solution)
1 kg = 1000 g
1 g = 1000 mg
1 mg = 1000 micrograms
1 microgram = 1000 nanograms
1 L = 1000 ml
1 ml = 1000 microliters
1 pint = 568 ml
1 fl oz = 28.4 ml
1 hour = 60 minutes
1 day = 24 hours
1 week = 7 days
°C = (°F - 32) × 5/9
°F = (°C × 9/5) + 32
Printable PDF with all formulas and conversion factors
Timed calculation sessions to build speed and accuracy under pressure. Compete with other students and track improvement.
Detailed analytics showing your improvement across different calculation types. Identify weak areas and track mastery.
Structured learning paths that build from basic concepts to advanced problems. Perfect for systematic improvement.
Join thousands of students who've conquered their calculation fears and passed their GPhC exam
Start Calculation Practice350+ problems • Step-by-step solutions • Formula reference included