Part 1 is numerically unforgiving. 40 calculations with free-entry answers (not MCQ) in 2 hours. No partial credit. No elimination strategy. You must calculate the correct answer.
Calculation types: IV infusion rates, dose per kg, renal/hepatic dose adjustments, dilutions, concentration conversions, displacement values, BMI, BSA, quantity to supply.
Resources: Pre-Reg Shortcuts (dedicated Part 1 content, timed webinar sessions), Focus Pre-Reg (Part 1 calculations with BNF data practice), OnTrack (calculation questions), iatroX (calculation coverage within adaptive framework), pharmacy calculations textbooks (Rees/Smith, Ansel).
BNF integration: Many calculations require extracting dosing data from BNF entries — practise this specifically. Finding the right strength, formulation, and dosing schedule under time pressure is a separate skill from the maths.
Common failure pattern: Strong on Part 2 clinical knowledge, weak on Part 1 calculations. Must pass both on the same day. Do not neglect calculations because clinical feels more comfortable.
Strategy: Daily timed calculation practice from week 1 of revision — 10 questions per day initially, increasing to 20 per day from week 5.
iatroX's GPhC Q-bank covers calculation-based questions alongside clinical therapeutics — adaptive scheduling ensures calculations are not neglected.