A free study tool from MedTestBank.com, nursing test banks for the textbooks your program uses.Visit MedTestBank.com
MedTestBankDosage Calculation for Nursing

Weight-based dosage calculation practice problems

Dosage calculation practice for nursing students: solve unlimited new problems below with instant checking, or work through the 15 problems with answers further down.

Unlimited new problems

New problems every time. Your score stays on this device.

Loading a problem…

Formula to use

Weight (kg) = weight (lb) ÷ 2.2

Dose = dose per kg × weight in kg

Dose per dose = daily dose ÷ number of doses per day

Open the weight-based dosage (mg/kg) calculator to check your own numbers step by step.

15 practice problems with answers

Solve each problem on paper first, then open the answer to compare every step.

  1. Order: ceftriaxone 50 mg/kg IV once daily. The child weighs 50 lb. How many mg will you give? Round the weight in kg to the tenth first.

    Show the answer
    1. Convert: 50 lb ÷ 2.2 = 22.7 kg.
    2. Dose = 50 mg/kg × 22.7 kg = 1,135 mg, rounded to 1,135 mg.

    Answer: 1,135 mg

  2. Order: ceftriaxone 50 mg/kg IV once daily. The child weighs 20 kg. How many mg will you give?

    Show the answer
    1. Dose = 50 mg/kg × 20 kg = 1,000 mg, rounded to 1,000 mg.

    Answer: 1,000 mg

  3. Order: ibuprofen 10 mg/kg PO every 8 hours as needed for fever. The child weighs 22.9 kg. How many mg will you give?

    Show the answer
    1. Dose = 10 mg/kg × 22.9 kg = 229 mg, rounded to 229 mg.

    Answer: 229 mg

  4. Order: dexamethasone 0.6 mg/kg PO once for croup. The child weighs 23.7 kg. How many mg will you give?

    Show the answer
    1. Dose = 0.6 mg/kg × 23.7 kg = 14.22 mg, rounded to 14.2 mg.

    Answer: 14.2 mg

  5. Order: ceftriaxone 50 mg/kg IV once daily. The child weighs 39 lb. How many mg will you give? Round the weight in kg to the tenth first.

    Show the answer
    1. Convert: 39 lb ÷ 2.2 = 17.7 kg.
    2. Dose = 50 mg/kg × 17.7 kg = 885 mg, rounded to 885 mg.

    Answer: 885 mg

  6. Order: heparin 80 units/kg IV bolus. The patient weighs 84 kg. How many units will you give?

    Show the answer
    1. Dose = 80 units/kg × 84 kg = 6,720 units, rounded to 6,720 units.

    Answer: 6,720 units

  7. Order: ibuprofen 10 mg/kg PO every 8 hours as needed for fever. The child weighs 14.7 kg. How many mg will you give?

    Show the answer
    1. Dose = 10 mg/kg × 14.7 kg = 147 mg, rounded to 147 mg.

    Answer: 147 mg

  8. Order: acetaminophen 15 mg/kg PO every 6 hours as needed for fever. The child weighs 20.2 kg. How many mg will you give?

    Show the answer
    1. Dose = 15 mg/kg × 20.2 kg = 303 mg, rounded to 303 mg.

    Answer: 303 mg

  9. Order: ceftriaxone 50 mg/kg IV once daily. The child weighs 10.5 kg. How many mg will you give?

    Show the answer
    1. Dose = 50 mg/kg × 10.5 kg = 525 mg, rounded to 525 mg.

    Answer: 525 mg

  10. Order: dexamethasone 0.6 mg/kg PO once for croup. The child weighs 22 lb. How many mg will you give? Round the weight in kg to the tenth first.

    Show the answer
    1. Convert: 22 lb ÷ 2.2 = 10 kg.
    2. Dose = 0.6 mg/kg × 10 kg = 6 mg, rounded to 6 mg.

    Answer: 6 mg

  11. Order: ibuprofen 10 mg/kg PO every 8 hours as needed for fever. The child weighs 61 lb. How many mg will you give? Round the weight in kg to the tenth first.

    Show the answer
    1. Convert: 61 lb ÷ 2.2 = 27.7 kg.
    2. Dose = 10 mg/kg × 27.7 kg = 277 mg, rounded to 277 mg.

    Answer: 277 mg

  12. Order: ceftriaxone 50 mg/kg IV once daily. The child weighs 21.2 kg. How many mg will you give?

    Show the answer
    1. Dose = 50 mg/kg × 21.2 kg = 1,060 mg, rounded to 1,060 mg.

    Answer: 1,060 mg

  13. Order: ibuprofen 10 mg/kg PO every 8 hours as needed for fever. The child weighs 25.1 kg. How many mg will you give?

    Show the answer
    1. Dose = 10 mg/kg × 25.1 kg = 251 mg, rounded to 251 mg.

    Answer: 251 mg

  14. Order: vancomycin 15 mg/kg IV every 12 hours. The patient weighs 172 lb. How many mg will you give? Round the weight in kg to the tenth first.

    Show the answer
    1. Convert: 172 lb ÷ 2.2 = 78.2 kg.
    2. Dose = 15 mg/kg × 78.2 kg = 1,173 mg, rounded to 1,173 mg.
    3. In practice, the pharmacy usually rounds vancomycin doses (often to the nearest 250 mg) and adjusts them to drug levels.

    Answer: 1,173 mg

  15. Order: vancomycin 15 mg/kg IV every 12 hours. The patient weighs 81.5 kg. How many mg will you give?

    Show the answer
    1. Dose = 15 mg/kg × 81.5 kg = 1,222.5 mg, rounded to 1,222.5 mg.
    2. In practice, the pharmacy usually rounds vancomycin doses (often to the nearest 250 mg) and adjusts them to drug levels.

    Answer: 1,222.5 mg