PEBC Calculations Questions: Types, Formulas and Worked Steps
Updated · 7 min read
As at 12 Oct 2026, PEBC lists calculations among the themes its Part I forms are built around, and you work them with only the on-screen calculator and the formula sheet PEBC provides (pebc.ca FAQ and Part I (MCQ) page). Expect dose, renal function, infusion, concentration and biostatistics questions, each with four numeric options.
The types to expect
| Type | What you calculate | Key formula |
|---|---|---|
| Weight-based dose | mg per dose or per day | dose = mg/kg × weight (kg) |
| Body size | BSA, ideal and adjusted body weight | Mosteller; Devine; AdjBW = IBW + 0.4 × (TBW − IBW) |
| Renal function | creatinine clearance, then dose adjustment | Cockcroft-Gault (SI) |
| Infusions | mL/h and drops/min | mL/h = volume ÷ hours; drops/min = mL/min × drop factor |
| Concentrations and dilutions | strength, final volume | C1 × V1 = C2 × V2 |
| Electrolytes | mmol or mEq | mmol = mg ÷ molar mass |
| Days' supply and quantity | units to dispense | quantity = dose × frequency × days |
| Biostatistics | ARR, NNT, RR, OR, sensitivity | NNT = 1 ÷ ARR |
Worked examples
Creatinine clearance (Cockcroft-Gault, SI)
A 70 year old man weighs 60 kg; serum creatinine 110 µmol/L.
CrCl = (140 − 70) × 60 × 1.23 ÷ 110 = 46.96, about 47 mL/min.
For a woman, multiply by 0.85: about 40 mL/min.
Infusion rate
1,000 mL to run over 8 hours with a 15 drops/mL set.
Rate = 1,000 ÷ 8 = 125 mL/h = 2.08 mL/min.
Drops = 2.08 × 15 = 31 drops/min.
Number needed to treat
Event rate 12% on control, 8% on treatment.
ARR = 12% − 8% = 4% = 0.04.
NNT = 1 ÷ 0.04 = 25 (round up).
Body surface area (Mosteller)
Height 170 cm, weight 70 kg.
BSA = √(170 × 70 ÷ 3600) = √3.31 = 1.82 m².
How to work them on the clock
- Write the units at every step; most wrong options come from a missed conversion (lb to kg, mg to g, hours to minutes).
- Check which weight the question wants: actual, ideal or adjusted.
- Estimate first, then calculate: an answer ten times too big is usually a decimal slip.
- Use the calculator's memory for multi-step questions rather than re-typing.
Sources
- PEBC, Qualifying Examination Part I (MCQ), pebc.ca (checked 12 Oct 2026)
- PEBC, Pharmacist Qualifying Examination Blueprint, Ver. 03-2026 (as of May 2026), pebc.ca (checked 12 Oct 2026)
- PEBC, Examination Design and Style, pebc.ca; PEBC sample questions PDF (Sept 2026) (checked 12 Oct 2026)
PEBC can change its format, fees and dates. Confirm on pebc.ca before you apply.
Frequently asked questions
Does the PEBC MCQ have calculations?
Yes. PEBC lists calculations among the themes each form is built around; you get an on-screen calculator and a formula sheet.
Which Cockcroft-Gault formula is used in Canada?
In SI units: CrCl (mL/min) = (140 − age) × weight (kg) × 1.23 ÷ SCr (µmol/L), multiplied by 0.85 for females.
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