ATI RN DOSAGE CALCULATION – 35 QUESTIONS STUDY
GUIDE
CORE DOMAINS
Basic Dosage Calculations: The D/H × Q Formula
Oral Medication Calculations: Tablets, Capsules, and Liquids
Injectable Medication Calculations: IM, SubQ, and IV Push
Intravenous Flow Rate Calculations: mL/hr and gtt/min
Weight-Based Dosage Calculations: mg/kg and mg/kg/day
Reconstitution and Dilution of Powdered Medications
Unit Conversions: Metric, Household, and Apothecary Systems
Safe Dosage Range Verification and High-Alert Medications
INTRODUCTION
This comprehensive study guide is designed to prepare nursing students
for the ATI RN Dosage Calculation Proctored Assessment. It presents 35
exam-style questions covering the core content areas tested on the ATI
dosage calculation exam, including the D/H × Q formula, oral and injectable
medication calculations, IV flow rates, weight-based dosing, and
reconstitution. Each question is followed by a detailed, step-by-step
rationale applying ATI methodology and the six rights of safe medication
administration. Emphasis is placed on dimensional analysis, ratio-
proportion, and the Desired/Have formula to build calculation fluency and
clinical judgment for safe nursing practice.
SECTION ONE: QUESTIONS 1–35
1. A postoperative patient reports incisional pain rated 7/10. The
provider orders acetaminophen 650 mg PO every 6 hours PRN. The
pharmacy stocks acetaminophen 325 mg tablets. How many tablets
should the nurse administer per dose?
A. 1 tablet
B. 1.5 tablets
C. 2 tablets
D. 3 tablets
, C. 2 tablets
RATIONALE: Using the Desired/Have × Quantity formula: 650 mg ÷
325 mg × 1 tablet = 2 tablets. Option A reflects administering only one
tablet (underdose); option D reflects doubling the dose (overdose). ATI
methodology requires verifying the 24-hour total stays within the
acetaminophen safe maximum of 4 g/day; 650 mg q6h = 2.6 g/day, well
within the limit.
2. A provider orders amoxicillin 500 mg PO. The pharmacy supplies
amoxicillin oral suspension 250 mg/5 mL. How many mL should the
nurse draw up in the oral syringe?
A. 5 mL
B. 10 mL
C. 2.5 mL
D. 15 mL
B. 10 mL
RATIONALE: D/H × Q = 500 mg ÷ 250 mg × 5 mL = 10 mL. Option A is
the volume per 250 mg dose (underdose), option C reverses the ratio (250
÷ 500 × 5 = 2.5), and option D doubles the calculation. Per ATI oral-liquid
convention, mL answers are rounded to the nearest tenth; here 10 mL is
exact.
3. An 82-year-old patient with atrial fibrillation and heart failure is
prescribed digoxin 0.25 mg PO daily. The pharmacy stocks digoxin
0.125 mg tablets. How many tablets should the nurse administer?
A. 0.5 tablet
B. 1 tablet
C. 1.5 tablets
D. 2 tablets
D. 2 tablets
RATIONALE: D/H × Q = 0.25 mg ÷ 0.125 mg × 1 tablet = 2 tablets.
Digoxin is a high-alert medication with a narrow therapeutic index. The
GUIDE
CORE DOMAINS
Basic Dosage Calculations: The D/H × Q Formula
Oral Medication Calculations: Tablets, Capsules, and Liquids
Injectable Medication Calculations: IM, SubQ, and IV Push
Intravenous Flow Rate Calculations: mL/hr and gtt/min
Weight-Based Dosage Calculations: mg/kg and mg/kg/day
Reconstitution and Dilution of Powdered Medications
Unit Conversions: Metric, Household, and Apothecary Systems
Safe Dosage Range Verification and High-Alert Medications
INTRODUCTION
This comprehensive study guide is designed to prepare nursing students
for the ATI RN Dosage Calculation Proctored Assessment. It presents 35
exam-style questions covering the core content areas tested on the ATI
dosage calculation exam, including the D/H × Q formula, oral and injectable
medication calculations, IV flow rates, weight-based dosing, and
reconstitution. Each question is followed by a detailed, step-by-step
rationale applying ATI methodology and the six rights of safe medication
administration. Emphasis is placed on dimensional analysis, ratio-
proportion, and the Desired/Have formula to build calculation fluency and
clinical judgment for safe nursing practice.
SECTION ONE: QUESTIONS 1–35
1. A postoperative patient reports incisional pain rated 7/10. The
provider orders acetaminophen 650 mg PO every 6 hours PRN. The
pharmacy stocks acetaminophen 325 mg tablets. How many tablets
should the nurse administer per dose?
A. 1 tablet
B. 1.5 tablets
C. 2 tablets
D. 3 tablets
, C. 2 tablets
RATIONALE: Using the Desired/Have × Quantity formula: 650 mg ÷
325 mg × 1 tablet = 2 tablets. Option A reflects administering only one
tablet (underdose); option D reflects doubling the dose (overdose). ATI
methodology requires verifying the 24-hour total stays within the
acetaminophen safe maximum of 4 g/day; 650 mg q6h = 2.6 g/day, well
within the limit.
2. A provider orders amoxicillin 500 mg PO. The pharmacy supplies
amoxicillin oral suspension 250 mg/5 mL. How many mL should the
nurse draw up in the oral syringe?
A. 5 mL
B. 10 mL
C. 2.5 mL
D. 15 mL
B. 10 mL
RATIONALE: D/H × Q = 500 mg ÷ 250 mg × 5 mL = 10 mL. Option A is
the volume per 250 mg dose (underdose), option C reverses the ratio (250
÷ 500 × 5 = 2.5), and option D doubles the calculation. Per ATI oral-liquid
convention, mL answers are rounded to the nearest tenth; here 10 mL is
exact.
3. An 82-year-old patient with atrial fibrillation and heart failure is
prescribed digoxin 0.25 mg PO daily. The pharmacy stocks digoxin
0.125 mg tablets. How many tablets should the nurse administer?
A. 0.5 tablet
B. 1 tablet
C. 1.5 tablets
D. 2 tablets
D. 2 tablets
RATIONALE: D/H × Q = 0.25 mg ÷ 0.125 mg × 1 tablet = 2 tablets.
Digoxin is a high-alert medication with a narrow therapeutic index. The
