The Part I reference sheet: seven formulas given, the rest to know
What the screen will give you on exam day, what it will not, and how to train with exactly the same tools.
Published on September 27, 2026 · 3 min read
On the day of Part I, the screen gives you two tools: a calculator and a reference sheet. At the test centre you also receive a dry-erase board and markers. That is all. The sheet carries only seven formulas, and that "only seven" changes how to prepare.
What the sheet gives
A legend defines four symbols — t½ the half-life, ke the elimination rate constant, D the dose, R0 the infusion rate — then come seven formulas in three families.
| Family | Formula |
|---|---|
| Pharmacokinetics | t½ = 0.693 ÷ ke |
| Css = R0 ÷ (ke × Vd) | |
| Cpk = D ÷ [Vd × (1 − e^(−ke × t))] | |
| Ct = C0 × e^(−ke × t) | |
| Creatinine clearance | CrCl (mL/min, male) = [(140 − age) × actual body weight (kg) × 1.2] ÷ serum creatinine (µmol/L) |
| CrCl (mL/min, female) = 0.85 × CrCl (male) | |
| Body mass index | BMI = weight (kg) ÷ height² (m²) |
Three details of this sheet matter in a calculation:
- The units are part of the formula. The constant 1.2 assumes creatinine in µmol/L and weight in kilograms: with other units, the result is wrong without looking wrong.
- The sheet says "actual body weight". If a case calls for another weight, knowing it is up to you: the sheet will not say.
- The decimal mark follows the language of the exam: 0.693 in English, 0,693 in French.
What it does not give
Everything else is known by heart. The calculation families the sheet leaves out, with the formula to know:
- Risk. Absolute risk reduction: ARR = control group risk − treated group risk. Relative risk: RR = treated group risk ÷ control group risk. Relative risk reduction: RRR = ARR ÷ control group risk, that is 1 − RR. Number needed to treat: NNT = 1 ÷ ARR, rounded up to the next whole number.
- Dilutions. C1 × V1 = C2 × V2, both concentrations in the same unit.
- Concentrations. A weight-in-volume percentage is a number of grams per 100 mL; a 1:1000 strength is 1 g per 1000 mL, that is 0.1%.
- Alligation. To prepare an intermediate concentration from a stronger and a weaker one: the share of the stronger is the gap between the target and the weaker, the share of the weaker is the gap between the stronger and the target.
- Loading dose. Volume of distribution × target concentration, divided by the bioavailability F when the route is not intravenous, and by the active fraction S when the drug is a salt.
This list is not exhaustive. It names what the sheet will not give back, so you do not find out on exam day.
Training with the tools of exam day
Training that provides more than the exam builds a reflex the exam does not reward. On RxSprint, three rules follow:
- The training sheet is the exam's sheet: the same seven formulas, in the same order, with the same legend, and nothing else, in the sprint as in the timed block.
- No stem supplies a formula. A question that opens with "Formula provided: NNT = 1 ÷ ARR" does not measure what the exam measures. Our stems give the data of the case, never the formula.
- The calculator computes in the order you press, like a desk calculator: 2 + 3 × 4 gives 20. Knowing it before the exam avoids a mistake that has nothing to do with pharmacy.
A calculation question then plays out in three steps: the formula, which you know or the sheet gives; the units, aligned before computing; the check, twenty seconds to verify the order of magnitude. A right but slow calculation, when it comes back, becomes a reflex to work on: the Réflexes series takes it up again until it fits the budget.