Dosage Practice

HESI Dosage Calculation Practice: What's on It and How to Prepare

The HESI dosage calculations exam tests the same math every nursing program teaches: unit conversions, oral and injectable doses, weight-based doses and IV rates, each with one exact numeric answer. Most programs set a pass mark of 90% or higher, so there is little room for rounding slips.

How to prepare

  1. 1 Know the textbook conversions cold: 1 kg = 2.2 lb, 1 tsp = 5 mL, 1 g = 1,000 mg, 1 mg = 1,000 mcg.
  2. 2 Read the rounding instruction on every question before you calculate. Tenths, hundredths and whole numbers are all used.
  3. 3 Use one method you trust, dimensional analysis or desired-over-have, and write the set-up down even on a computer exam.
  4. 4 Practice under time. Fast, correct arithmetic comes from repetition, not from reading about it.

Worked Examples

Example 1

Ordered: 0.5 g by mouth. Available: 250 mg tablets. How many tablets?

  1. 0.5 g = 500 mg.
  2. 500 ÷ 250 = 2 tablets.

Answer: 2 tablets

Example 2

Order: 500 mL over 4 hours by gravity, drop factor 20 gtt/mL. Drops per minute?

  1. 4 hours = 240 minutes.
  2. 500 × 20 ÷ 240 = 41.67, rounded to 42.

Answer: 42 gtt/min

Try five free problems

One exact answer, rounded as asked, no partial credit. No sign-up needed.

Problem 1 of 5No sign-up needed

Convert 250 mcg to mg.

exact answer, no rounding needed

mg

Common Mistakes

  • Losing points on rounding, not on math

    The arithmetic is right and the answer is still marked wrong because it was rounded to the wrong place, or written as 5.0. Practice the rounding rules until they are reflex.

  • Converting the weight wrong

    Pounds divided by 2.2, rounded to tenths, before anything else. A weight error carries into every later step.

  • Rushing the question

    Per dose or per day? mL/hr or gtt/min? Underline what is asked before calculating.

Questions Students Ask

How many questions are on the HESI dosage calculation exam?

It varies by program; check with your school. Whatever the number, every question is a short calculation with a single numeric answer.

What score do I need?

Your program sets it. 90% is common and some require 100%. Our mock exam uses 100% so that any pass mark feels achievable.

Is this site affiliated with HESI or Elsevier?

No. HESI is a registered trademark of Elsevier. We prepare students for the math it tests; we have no connection with the company.

Practice until it feels easy

Work through the lessons with fresh numbers every time. The practice round and the first five problems of lesson 1 are free.

See all lessons