40 calculations. Free-entry answers. 2 hours. 3 minutes per question. No MCQ options to eliminate. No partial credit.
Common calculation types: IV infusion rates (ml/hr, drops/min), dose per kg (paediatric, weight-based), renal/hepatic dose adjustments, dilutions and concentrations, displacement values, BMI and BSA calculations, quantity to supply calculations.
BNF integration: Many questions require extracting data from BNF-style entries — drug strengths, formulation concentrations, dosing schedules. The maths is straightforward; finding the correct data to put into the calculation is where candidates make errors.
Rounding and significant figures: A correct calculation with wrong rounding is wrong. Understand conventions for different answer types.
Practice strategy: 10 timed calculations daily from week 1 of revision. Increase to 20/day from week 5. Strict timing — 3 minutes per question, no calculator review time.
Common errors: Unit conversion mistakes (mg to g, ml to L). Decimal point errors. Not reading the question stem fully — missing critical information like "calculate the DAILY dose" vs "calculate the SINGLE dose."
iatroX's GPhC Q-bank includes calculation-based questions within the adaptive framework — ensuring daily calculation practice is part of your personalised revision schedule.