Dosage Calculation Practice: Free Unlimited Problems

Practice problems

Pick a problem type or mix them all. Type your answer and check it. Round only your final answer, the way each problem tells you.

The formulas

Convert to matching units first, then set up the problem. These six cover almost every calculation item.

Tablets, liquids and injections

(D ÷ H) × Q

D = dose ordered, H = dose on hand, Q = the tablets or mL that hold H.

IV pump rate

mL/hr = volume (mL) ÷ time (hr)

For a time in minutes: mL ÷ min × 60.

Gravity drip rate

gtt/min = (mL × gtt/mL) ÷ min

Drop factor is on the tubing: macrodrip 10, 15 or 20 gtt/mL; microdrip 60 gtt/mL.

Weight-based dose

dose = mg/kg × kg

Convert pounds to kilograms first: lb ÷ 2.2.

Heparin infusion

mL/hr = units/hr ÷ units/mL

Concentration = units in the bag ÷ mL in the bag. 25,000 units in 250 mL = 100 units/mL.

Dimensional analysis

order × (on hand ÷ unit) …

Line up conversion factors so every unit cancels except the one you want.

Conversions and rounding rules

Round only the final answer, and follow the problem's instructions. NCLEX calculation items say how to round.
Common conventions when no rule is given: mL to the tenth, drops to the whole number, scored tablets to the half tablet.
Always use a leading zero (0.5 mg) and never a trailing zero (5 mg, not 5.0 mg). Both errors can cause a tenfold overdose. They are on The Joint Commission's "Do Not Use" list and ISMP's error-prone abbreviations list.
Check whether your answer makes sense: more than 3 tablets or more than 3 mL in one IM injection is a reason to recheck.

1 g = 1,000 mg

1 mg = 1,000 mcg

1 L = 1,000 mL

1 kg = 2.2 lb

1 hr = 60 min

Keep going

Try 10 real NCLEX questionsFrom the Progress Note bank, each with a cited explanation. No account needed. Medication safety guideRights of administration, high-alert drugs and error prevention. IV therapy guideFluids, complications and what to do first.

Questions students ask

Is dosage calculation on the NCLEX?

Yes. The NCLEX-RN test plan lists performing calculations needed for medication administration under Pharmacological and Parenteral Therapies. Calculation items are usually fill-in-the-blank and tell you how to round.

What is the basic dosage calculation formula?

Desired over have, times quantity: (D ÷ H) × Q. D is the ordered dose, H is the dose on hand per unit, and Q is the volume or number of units that holds H. Convert D and H to the same unit first.

How do you calculate an IV drip rate in drops per minute?

Drops per minute = (total volume in mL × drop factor in gtt/mL) ÷ time in minutes. Round to the nearest whole drop, because you cannot count part of a drop.

When should I round in a dosage calculation?

Round only the final answer, and round the way the question tells you. Rounding in the middle of a problem can push the final answer outside the accepted value.

Sources

NCSBN. 2026 NCLEX-RN Test Plan (Pharmacological and Parenteral Therapies). nclex.com
The Joint Commission. Official "Do Not Use" List. jointcommission.org
Institute for Safe Medication Practices (ISMP, now part of ECRI). List of Error-Prone Abbreviations. ecri.org
Raschke RA, et al. The weight-based heparin dosing nomogram compared with a "standard care" nomogram. Ann Intern Med. 1993;119(9):874-881.

For study only. Problems use typical teaching values, not patient-specific orders. In practice, follow the prescriber's order, your facility's protocols and an independent double check for high-alert drugs such as heparin and insulin.