Tools
The two things candidates practise wrong
Almost nobody fails a dosage calculation on the arithmetic. They fail on a unit conversion they did in their head. And almost nobody misreads a lab value they were taught in the right units. These two tools exist because those are the two failures that are entirely preventable.
Dosage calculation drills
Eleven problem types, generated rather than stored, so the bank never runs out. Every answer comes with a line-by-line dimensional analysis showing where the units go.
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Lab values in SI units
Canadian reference ranges with conventional-unit equivalents, conversion factors, critical values, and the nursing action each abnormal result actually demands.
Open the reference →
Every calculation type on the exam
| Type | Formula | Where marks get lost |
|---|---|---|
| Tablet dosage | Tablets = Desired dose ÷ Available strength | Answering with a fraction of a tablet for an enteric-coated or extended-release form, which cannot be split. |
| Liquid dosage | Volume = (Desired ÷ Available) × Quantity | Forgetting that the available strength is per a stated volume, not per millilitre. |
| Weight-based dosage | Dose = Weight (kg) × Ordered dose per kg | Using a weight in pounds. Convert first: 1 kg = 2.2 lb. This is the single most common error on the exam. |
| IV flow rate (mL/hr) | mL/hr = Total volume (mL) ÷ Time (hr) | Leaving time in minutes when the pump wants hours. |
| IV drip rate (gtt/min) | gtt/min = (Volume mL × Drop factor gtt/mL) ÷ Time in minutes | Rounding drops to a decimal. Drops per minute are always whole numbers — you cannot count half a drop. |
| Infusion time | Time (hr) = Total volume (mL) ÷ Rate (mL/hr) | Reporting a decimal hour when the question asks for hours and minutes. |
| Unit conversion | 1 g = 1000 mg · 1 mg = 1000 mcg · 1 L = 1000 mL · 1 kg = 2.2 lb | Moving the decimal the wrong direction between mg and mcg. |
| Titration | mL/hr = (Dose × Weight × 60) ÷ Concentration (mcg/mL) | Dropping the ×60 that converts per-minute dosing into an hourly pump rate. |
| Reconstitution | Concentration = Total drug ÷ Final volume after reconstitution | Using the diluent volume as the final volume. The powder displaces fluid, so read the vial label. |
| Intake and output | Balance = Total intake − Total output | Forgetting that ice chips count as roughly half their volume, and gelatin counts as fluid. |
| Safe dose range | Safe range = Weight (kg) × low mg/kg → Weight (kg) × high mg/kg | Calculating the range correctly, then administering anyway. If the order is outside the range, the answer is to hold and clarify. |