The general rules
- Do not round in the middle of a calculation: keep every digit and round the final answer only.
- Round up when the next digit is 5 or more, down when it is 4 or less.
- Always follow your program's or your facility's rules when they differ from these common conventions.
By type of answer
| Answer | Round to | Example |
|---|---|---|
| Tablets | Whole tablet, or half tablet only if scored | 1.5 tablets of a scored tablet |
| Capsules | Whole capsule (never split) | 2 capsules |
| mL, 1 mL or more | Tenth | 7.48 mL → 7.5 mL |
| mL, less than 1 mL | Hundredth (1 mL syringe) | 0.256 mL → 0.26 mL |
| Drops per minute | Whole drop | 31.25 → 31 gtt/min |
| Pump rate | Tenth (or whole number if required) | 83.33 → 83.3 mL/hr |
| Weight | Tenth of a kg | 20.45 kg → 20.5 kg |
| BSA | Hundredth | 1.791 m² → 1.79 m² |
| Temperature | Tenth | 38.55 °C → 38.6 °C |
Leading and trailing zeros
Always write a zero before a decimal point (0.5 mg, never .5 mg): a missed decimal point turns the dose into 5 mg.
Never write a zero after a whole number (5 mg, never 5.0 mg): a missed decimal point turns it into 50 mg. Both rules are on The Joint Commission's official Do Not Use list.
Frequently asked questions
Do you round mL to the tenth or the hundredth?
To the tenth when the volume is 1 mL or more, to the hundredth when it is less than 1 mL, which is measured with a 1 mL syringe.
Do you round in the middle of a dosage calculation?
No. Rounding intermediate steps can change the final answer. Round only the final answer, except when the problem tells you to round the weight first.