Part 1 calculations is the most predictable failure point in the GPhC registration assessment. In June 2025, 16% of candidates failed Part 1 alone — and their entire sitting was wasted regardless of Part 2 performance. The calculation types are finite, the calculator is allowed, and practice directly translates to improved performance. The question is not whether to prepare specifically for Part 1 — it is how.
Two platforms dominate the calculations course space: Pharmacy Masterclass and Pre-Reg Shortcuts. Both offer structured calculation drilling. Both have loyal followings. But they take different approaches — and understanding the differences helps you choose the right one for your learning style.
Pharmacy Masterclass
Pharmacy Masterclass provides intensive calculation courses — typically structured as taught sessions (live or recorded) walking through each calculation type with worked examples and practice sets. The teaching is systematic, moving from basic dose calculations through to complex IV infusion rates, displacement values, and concentration expressions.
Strengths: The taught format is strong for trainees who struggle with calculations and need someone to walk through the method step by step. The systematic progression from simple to complex builds confidence. The worked examples are detailed.
Limitations: Taught courses are fixed in pace — you progress at the course speed, not your speed. If you already understand dose calculations but struggle with displacement values, you still sit through the dose calculation session. No adaptive targeting. Typically requires booking a specific session date. No ongoing access to an adaptive practice engine after the course ends.
Best for: Trainees who learn best from taught instruction and need the method explained before they can practise independently.
Pre-Reg Shortcuts
Pre-Reg Shortcuts offers calculation drilling within its broader Q-bank platform, supplemented by live sessions and calculation-specific revision content. The calculation practice is integrated into the overall exam preparation rather than isolated as a standalone course.
Strengths: Integration with the broader Q-bank means you can practise calculations alongside Part 2 content in a single platform. The live sessions provide interactive calculation teaching. The community element means you can ask questions and see where other trainees struggle.
Limitations: Calculation practice is part of a larger platform — if you only need Part 1 help, you are paying for the full platform. No adaptive difficulty within calculation types — you see the same mix regardless of which types you struggle with. Web-only.
Best for: Trainees who want calculations integrated into their overall revision platform rather than as a separate course.
The Gap Both Leave
Both approaches share a fundamental limitation: they are not adaptive to your individual calculation weaknesses. A course teaches every type at the same pace regardless of your proficiency. A static Q-bank serves calculation questions in rotation regardless of which types you get wrong.
iatroX addresses this directly. The Part 1 calculation engine tracks your accuracy and speed across each calculation type independently. If you are fast and accurate on IV infusion rates but consistently slow on displacement values, the engine concentrates your practice on displacement — with difficulty scaling as you improve within that specific type.
The performance dashboard shows accuracy AND speed by calculation type — because Part 1 is a time-pressure exam (40 questions, 120 minutes) where knowing the method is insufficient without the pace.
The Recommended Approach
If you need the method taught: Take a Pharmacy Masterclass or Pre-Reg Shortcuts course to learn the calculation methods. Then switch to iatroX for adaptive drilling that targets your specific weak calculation types under timed conditions.
If you already know the methods but need practice: Skip the course. Use iatroX directly — the adaptive engine will identify which types need work and concentrate practice there.
Start at iatrox.com/quiz-landing?exam=uk-gphc.