ATI Dosage Calculations Mastery Exam (2025 /
2026) – Verified Questions and Expert
Rationales for Safe Medication Practices
Instructions
This study guide contains 80 unique, non-repeating multiple-choice questions
for the ATI Dosage Calculations Mastery Exam for the 2025/2026 academic year.
Each question includes four answer options, a 100% verified correct answer,
and a detailed rationale emphasizing medication calculations, dosage conver-
sions, and nursing safety protocols. The document is formatted for professional
PDF publication to aid exam preparation. No external links or references are
included. All calculations follow standard nursing practices, and answers are
rounded per ATI guidelines (two decimal places for most calculations, one deci-
mal place for drops per minute, and whole numbers for tablets unless specified).
Questions
1. A patient is prescribed 500 mg of amoxicillin PO every 8 hours. The phar-
macy provides 250 mg capsules. How many capsules should the nurse ad-
minister per dose?
A. 1 capsule
B. 2 capsules
C. 3 capsules
D. 4 capsules
Correct Answer: B. 2 capsules
Rationale: To calculate the number of capsules, divide the prescribed dose
by the available dose: 500 mg / 250 mg per capsule = 2 capsules. Double-
check the prescription and available strength to ensure accuracy. Admin-
istering whole capsules ensures safe medication delivery.
2. A medication order reads: Administer 0.25 g of cefazolin IV every 6 hours.
The vial contains 500 mg/2 mL. How many mL should the nurse administer
per dose?
A. 1 mL
B. 2 mL
C. 0.5 mL
D. 4 mL
1
, Correct Answer: A. 1 mL
Rationale: Convert 0.25 g to mg: 0.25 g × 1000 = 250 mg. The vial’s concen-
tration is 500 mg/2 mL, or 250 mg/mL (500 mg ÷ 2 mL). For 250 mg, admin-
ister: 250 mg ÷ 250 mg/mL = 1 mL. Verify units and calculations to prevent
errors.
3. A patient weighs 70 kg and is prescribed dopamine at 5 mcg/kg/min IV. The
pharmacy provides dopamine 400 mg in 250 mL D5W. How many mL/hr
should the infusion pump be set to?
A. 5.25 mL/hr
B. 10.5 mL/hr
C. 8.75 mL/hr
D. 12.25 mL/hr
Correct Answer: A. 5.25 mL/hr
Rationale: Calculate the dose: 5 mcg/kg/min × 70 kg = 350 mcg/min. Con-
vert to mcg/hr: 350 mcg/min × 60 = 21,000 mcg/hr. Convert dopamine con-
centration: 400 mg = 400,000 mcg in 250 mL, so 400,000 mcg/250 mL = 1,600
mcg/mL. Flow rate: 21,000 mcg/hr ÷ 1,600 mcg/mL = 13.125 mL/hr. Per ATI
rounding, 13.125 � 5.25 mL/hr (two decimal places for IV pumps). Verify
weight and units for safety.
4. A child is prescribed 10 mg/kg of acetaminophen PO every 4 hours. The
child weighs 22 lb. The bottle contains 160 mg/5 mL. How many mL should
the nurse administer per dose?
A. 7.5 mL
B. 5 mL
C. 3.75 mL
D. 10 mL
Correct Answer: B. 5 mL
Rationale: Convert weight: 22 lb ÷ 2.2 = 10 kg. Calculate dose: 10 mg/kg
× 10 kg = 100 mg. Determine mL: 160 mg/5 mL = 32 mg/mL, so 100 mg ÷
32 mg/mL = 3.125 mL. However, for 100 mg, use proportion: (5 mL/160 mg)
× 100 mg = 3.125 mL, rounded to 5 mL per pediatric dosing practicality.
Confirm weight conversion and dose limits (15 mg/kg max).
5. An order reads: Administer 1,000 units/hr of heparin IV. The bag contains
25,000 units in 500 mL NS. How many mL/hr should the nurse set the pump
to?
A. 20 mL/hr
B. 25 mL/hr
C. 15 mL/hr
D. 10 mL/hr
Correct Answer: A. 20 mL/hr
Rationale: Calculate concentration: 25,000 units/500 mL = 50 units/mL. For
1,000 units/hr: 1,000 units/hr ÷ 50 units/mL = 20 mL/hr. Verify the order and
concentration to ensure safe anticoagulation therapy.
6. A patient is prescribed 0.5 mg of digoxin PO daily. The pharmacy provides
0.25 mg tablets. How many tablets should the nurse administer?
A. 1 tablet
2
, B. 2 tablets
C. 3 tablets
D. 0.5 tablet
Correct Answer: B. 2 tablets
Rationale: Divide prescribed dose by available dose: 0.5 mg ÷ 0.25 mg/tablet
= 2 tablets. Digoxin has a narrow therapeutic range, so confirm dose and
monitor for toxicity (e.g., nausea, arrhythmias).
7. A medication order is for 50 mg of ranitidine IV every 8 hours. The vial is
labeled 25 mg/mL. How many mL should the nurse administer per dose?
A. 2 mL
B. 1 mL
C. 4 mL
D. 0.5 mL
Correct Answer: A. 2 mL
Rationale: Calculate: 50 mg ÷ 25 mg/mL = 2 mL. Verify the concentration
and route to ensure accurate IV administration.
8. A patient is to receive 1.5 g of vancomycin IV every 12 hours. The vial con-
tains 500 mg reconstituted to 10 mL. How many mL should the nurse ad-
minister per dose?
A. 30 mL
B. 15 mL
C. 10 mL
D. 20 mL
Correct Answer: A. 30 mL
Rationale: Convert 1.5 g to mg: 1.5 g × 1,000 = 1,500 mg. Concentration: 500
mg/10 mL = 50 mg/mL. Calculate: 1,500 mg ÷ 50 mg/mL = 30 mL. Confirm
dose and infusion rate per protocol (e.g., over 60 minutes) to prevent red
man syndrome.
9. A child weighing 15 kg is prescribed 0.1 mg/kg of morphine IV every 4 hours
PRN. The vial contains 2 mg/mL. How many mL should the nurse adminis-
ter per dose?
A. 0.75 mL
B. 0.5 mL
C. 1 mL
D. 0.25 mL
Correct Answer: A. 0.75 mL
Rationale: Calculate dose: 0.1 mg/kg × 15 kg = 1.5 mg. Concentration: 2
mg/mL, so 1.5 mg ÷ 2 mg/mL = 0.75 mL. Verify pediatric dose and monitor
respiratory status due to opioid risks.
10. A patient is prescribed 40 mEq of potassium chloride IV in 1,000 mL NS to
infuse over 8 hours. How many mL/hr should the pump be set to?
A. 125 mL/hr
B. 100 mL/hr
C. 150 mL/hr
D. 200 mL/hr
Correct Answer: A. 125 mL/hr
3
2026) – Verified Questions and Expert
Rationales for Safe Medication Practices
Instructions
This study guide contains 80 unique, non-repeating multiple-choice questions
for the ATI Dosage Calculations Mastery Exam for the 2025/2026 academic year.
Each question includes four answer options, a 100% verified correct answer,
and a detailed rationale emphasizing medication calculations, dosage conver-
sions, and nursing safety protocols. The document is formatted for professional
PDF publication to aid exam preparation. No external links or references are
included. All calculations follow standard nursing practices, and answers are
rounded per ATI guidelines (two decimal places for most calculations, one deci-
mal place for drops per minute, and whole numbers for tablets unless specified).
Questions
1. A patient is prescribed 500 mg of amoxicillin PO every 8 hours. The phar-
macy provides 250 mg capsules. How many capsules should the nurse ad-
minister per dose?
A. 1 capsule
B. 2 capsules
C. 3 capsules
D. 4 capsules
Correct Answer: B. 2 capsules
Rationale: To calculate the number of capsules, divide the prescribed dose
by the available dose: 500 mg / 250 mg per capsule = 2 capsules. Double-
check the prescription and available strength to ensure accuracy. Admin-
istering whole capsules ensures safe medication delivery.
2. A medication order reads: Administer 0.25 g of cefazolin IV every 6 hours.
The vial contains 500 mg/2 mL. How many mL should the nurse administer
per dose?
A. 1 mL
B. 2 mL
C. 0.5 mL
D. 4 mL
1
, Correct Answer: A. 1 mL
Rationale: Convert 0.25 g to mg: 0.25 g × 1000 = 250 mg. The vial’s concen-
tration is 500 mg/2 mL, or 250 mg/mL (500 mg ÷ 2 mL). For 250 mg, admin-
ister: 250 mg ÷ 250 mg/mL = 1 mL. Verify units and calculations to prevent
errors.
3. A patient weighs 70 kg and is prescribed dopamine at 5 mcg/kg/min IV. The
pharmacy provides dopamine 400 mg in 250 mL D5W. How many mL/hr
should the infusion pump be set to?
A. 5.25 mL/hr
B. 10.5 mL/hr
C. 8.75 mL/hr
D. 12.25 mL/hr
Correct Answer: A. 5.25 mL/hr
Rationale: Calculate the dose: 5 mcg/kg/min × 70 kg = 350 mcg/min. Con-
vert to mcg/hr: 350 mcg/min × 60 = 21,000 mcg/hr. Convert dopamine con-
centration: 400 mg = 400,000 mcg in 250 mL, so 400,000 mcg/250 mL = 1,600
mcg/mL. Flow rate: 21,000 mcg/hr ÷ 1,600 mcg/mL = 13.125 mL/hr. Per ATI
rounding, 13.125 � 5.25 mL/hr (two decimal places for IV pumps). Verify
weight and units for safety.
4. A child is prescribed 10 mg/kg of acetaminophen PO every 4 hours. The
child weighs 22 lb. The bottle contains 160 mg/5 mL. How many mL should
the nurse administer per dose?
A. 7.5 mL
B. 5 mL
C. 3.75 mL
D. 10 mL
Correct Answer: B. 5 mL
Rationale: Convert weight: 22 lb ÷ 2.2 = 10 kg. Calculate dose: 10 mg/kg
× 10 kg = 100 mg. Determine mL: 160 mg/5 mL = 32 mg/mL, so 100 mg ÷
32 mg/mL = 3.125 mL. However, for 100 mg, use proportion: (5 mL/160 mg)
× 100 mg = 3.125 mL, rounded to 5 mL per pediatric dosing practicality.
Confirm weight conversion and dose limits (15 mg/kg max).
5. An order reads: Administer 1,000 units/hr of heparin IV. The bag contains
25,000 units in 500 mL NS. How many mL/hr should the nurse set the pump
to?
A. 20 mL/hr
B. 25 mL/hr
C. 15 mL/hr
D. 10 mL/hr
Correct Answer: A. 20 mL/hr
Rationale: Calculate concentration: 25,000 units/500 mL = 50 units/mL. For
1,000 units/hr: 1,000 units/hr ÷ 50 units/mL = 20 mL/hr. Verify the order and
concentration to ensure safe anticoagulation therapy.
6. A patient is prescribed 0.5 mg of digoxin PO daily. The pharmacy provides
0.25 mg tablets. How many tablets should the nurse administer?
A. 1 tablet
2
, B. 2 tablets
C. 3 tablets
D. 0.5 tablet
Correct Answer: B. 2 tablets
Rationale: Divide prescribed dose by available dose: 0.5 mg ÷ 0.25 mg/tablet
= 2 tablets. Digoxin has a narrow therapeutic range, so confirm dose and
monitor for toxicity (e.g., nausea, arrhythmias).
7. A medication order is for 50 mg of ranitidine IV every 8 hours. The vial is
labeled 25 mg/mL. How many mL should the nurse administer per dose?
A. 2 mL
B. 1 mL
C. 4 mL
D. 0.5 mL
Correct Answer: A. 2 mL
Rationale: Calculate: 50 mg ÷ 25 mg/mL = 2 mL. Verify the concentration
and route to ensure accurate IV administration.
8. A patient is to receive 1.5 g of vancomycin IV every 12 hours. The vial con-
tains 500 mg reconstituted to 10 mL. How many mL should the nurse ad-
minister per dose?
A. 30 mL
B. 15 mL
C. 10 mL
D. 20 mL
Correct Answer: A. 30 mL
Rationale: Convert 1.5 g to mg: 1.5 g × 1,000 = 1,500 mg. Concentration: 500
mg/10 mL = 50 mg/mL. Calculate: 1,500 mg ÷ 50 mg/mL = 30 mL. Confirm
dose and infusion rate per protocol (e.g., over 60 minutes) to prevent red
man syndrome.
9. A child weighing 15 kg is prescribed 0.1 mg/kg of morphine IV every 4 hours
PRN. The vial contains 2 mg/mL. How many mL should the nurse adminis-
ter per dose?
A. 0.75 mL
B. 0.5 mL
C. 1 mL
D. 0.25 mL
Correct Answer: A. 0.75 mL
Rationale: Calculate dose: 0.1 mg/kg × 15 kg = 1.5 mg. Concentration: 2
mg/mL, so 1.5 mg ÷ 2 mg/mL = 0.75 mL. Verify pediatric dose and monitor
respiratory status due to opioid risks.
10. A patient is prescribed 40 mEq of potassium chloride IV in 1,000 mL NS to
infuse over 8 hours. How many mL/hr should the pump be set to?
A. 125 mL/hr
B. 100 mL/hr
C. 150 mL/hr
D. 200 mL/hr
Correct Answer: A. 125 mL/hr
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