ATI Dosage and Calculation
Complete Exam Pack · 45 Solved Problems
ATI Testing | Dosage and Calculation Assessment | Updated 2026/2027
Metric & Household Conversions · Oral & Liquid Dosage · IV Flow Rates & Drop Factors · IVPB & Continuous
Infusions
Pediatric & Weight-Based Dosing · Geriatric Adjustments · Dimensional Analysis · Clinical Safety & Error
Prevention
Undergraduate Nursing | Timed Calculation & Clinical Scenario Format | 45 Questions · 2-Hour Limit · NCLEX-
RN Readiness
Exam Structure
The ATI Dosage and Calculation Assessment for the 2026/2027 academic cycle is a 45-question
timed examination administered through the ATI Testing platform, consisting of multiple-choice,
fill-in-the-blank calculation, and clinical scenario items with a 2-hour time limit and standardized
scoring. Item weighting below reflects the distribution used throughout this pack.
Section Items Weighting Points
I — Metric, Household & Weight Conversions Q1–Q8 8 items × 1 pt 8 pts
II — Oral & Liquid Dosage Calculations Q9–Q16 8 items × 1 pt 8 pts
III — Parenteral Dosage & Reconstitution Q17–Q22 6 items × 1 pt 6 pts
IV — IV Flow Rates & Drop Factors Q23–Q30 8 items × 1 pt 8 pts
V — IV Piggyback & Continuous Infusions Q31–Q36 6 items × 2 pts 12 pts
VI — Pediatric & Weight-Based Dosing Q37–Q42 6 items × 2 pts 12 pts
VII — Geriatric, Safety & Clinical Judgment Q43–Q45 3 items × 2 pts 6 pts
TOTAL 45 items — 60 pts
Raw points total 60 and are reported by ATI as a percent-correct proficiency score benchmarked
to Level 2 and Level 3 standards; most programs require ≥ 90% on dosage calculation before
clinical placement.
Introduction
This guide prepares undergraduate nursing students on precise mathematical computation, safe
medication administration protocols, and clinical decision-making. The content emphasizes
dimensional analysis, ratio-proportion methods, IV infusion mathematics, weight-based dosing,
and error-prevention strategies aligned with ATI performance benchmarks, ISMP safety
guidelines, and NCLEX-RN standards, ensuring learners can accurately calculate dosages, verify
clinical appropriateness, and demonstrate competency in foundational medication safety.
ATI Testing · Dosage and Calculation Assessment · Complete Exam Pack · 2026–2027
,Core Formula Reference
The Three Calculation Methods
Method Formula When to Use
Desired over Have (D ÷ H) × Q = amount to administer Fastest for simple oral and
parenteral doses
Ratio-proportion H : Q :: D : x → cross-multiply and Useful when the relationship is
solve for x easier to see as a proportion
Dimensional analysis Order × conversion factors, arranged Most reliable for multi-step
so unwanted units cancel problems (mcg/kg/min, drip rates)
Infusion Formulas
Calculation Formula
Pump rate (mL/hr) Total volume (mL) ÷ Total time (hr)
Gravity rate (gtt/min) (mL/hr × drop factor) ÷ 60 min
IVPB rate (mL/hr) Volume × (60 ÷ minutes ordered)
Infusion time (hr) Total volume ÷ Rate (mL/hr)
Concentration Total drug ÷ Total volume
Units or mg per hour Concentration × Rate (mL/hr)
Rate from units/hr Ordered units/hr ÷ Concentration
Weight-based (mcg/kg/min) (mcg/kg/min × kg × 60) ÷ concentration in mcg/mL = mL/hr
Cockcroft-Gault CrCl [(140 − age) × kg] ÷ (72 × SCr); × 0.85 if female
Conversion Equivalents
Metric Equivalent Household / Other
1 kg 1,000 g 1 kg = 2.2 lb
1g 1,000 mg 1 tsp = 5 mL
1 mg 1,000 mcg 1 tbsp = 15 mL (3 tsp)
1L 1,000 mL 1 oz = 30 mL
1 mL 1 cc 1 cup = 8 oz = 240 mL
1 grain (gr) 60–65 mg 1 pint = 500 mL
Rounding Rules Used Throughout
• Tablets — to the nearest whole or half tablet (only scored tablets may be split).
• Oral and parenteral liquids — to the nearest tenth of a millilitre; volumes under 1 mL in
neonates, to the hundredth.
• Pump rates (mL/hr) — to the nearest whole number.
• Gravity drip rates (gtt/min) — to the nearest whole number, since a fraction of a drop cannot be
delivered.
• Round only at the final step; rounding intermediate values compounds error.
• Always use a leading zero (0.5 mg) and never a trailing zero (5 mg, not 5.0 mg).
ATI Testing · Dosage and Calculation Assessment · Complete Exam Pack · 2026–2027
, Section I · Metric, Household & Weight Conversions (Q1–Q8)
Question 1 (1 point · Fill in the Blank)
Convert 0.5 g to milligrams.
Step Set-Up Result
Identify the equivalent 1 g = 1,000 mg
Multiply (larger unit → 0.5 g × 1,000 mg/g 500 mg
smaller unit)
Correct Answer: 500 mg
Rationale: Moving from a larger metric unit to a smaller one multiplies by 1,000. Set the conversion factor
so the unwanted unit cancels: 0.5 g × (1,000 mg / 1 g) = 500 mg. A frequent error is dividing instead of
multiplying, which yields 0.0005 mg — a value so small it should immediately fail a common-sense check.
References: ATI Testing, Dosage Calculation and Safe Medication Administration 3.0; Lilley, Collins & Snyder,
Pharmacology and the Nursing Process, 10th ed. Ch. 34.
Question 2 (1 point · Fill in the Blank)
Convert 2,500 mL to liters.
Step Set-Up Result
Identify the equivalent 1 L = 1,000 mL
Divide (smaller unit → 2,500 mL ÷ 1,000 mL/L 2.5 L
larger unit)
Correct Answer: 2.5 L
Rationale: Converting from a smaller unit to a larger one divides by 1,000, so 2,500 mL becomes 2.5 L. Note
the leading zero rule does not apply here because the value exceeds 1; however, any answer less than 1 must
carry a leading zero (0.5 L, never .5 L) to prevent tenfold dosing errors.
References: ATI Testing, Dosage Calculation and Safe Medication Administration 3.0; Institute for Safe Medication
Practices (ISMP), List of Error-Prone Abbreviations and High-Alert Medications, 2024.
Question 3 (1 point · Fill in the Blank)
A client weighs 44 lb. What is the weight in kilograms?
Step Set-Up Result
Identify the equivalent 1 kg = 2.2 lb
Divide pounds by 2.2 44 lb ÷ 2.2 lb/kg 20 kg
Correct Answer: 20 kg
Rationale: Weight-based dosing is always calculated in kilograms, so pounds must be converted first: 44 ÷
2.2 = 20 kg. Multiplying by 2.2 instead would give 96.8 kg, more than four times the true weight — the single
most consequential conversion error in pediatric practice.
References: ATI Testing, Dosage Calculation and Safe Medication Administration 3.0; Institute for Safe Medication
Practices (ISMP), List of Error-Prone Abbreviations and High-Alert Medications, 2024; Lilley, Collins & Snyder,
Pharmacology and the Nursing Process, 10th ed. Ch. 34.
ATI Testing · Dosage and Calculation Assessment · Complete Exam Pack · 2026–2027
Complete Exam Pack · 45 Solved Problems
ATI Testing | Dosage and Calculation Assessment | Updated 2026/2027
Metric & Household Conversions · Oral & Liquid Dosage · IV Flow Rates & Drop Factors · IVPB & Continuous
Infusions
Pediatric & Weight-Based Dosing · Geriatric Adjustments · Dimensional Analysis · Clinical Safety & Error
Prevention
Undergraduate Nursing | Timed Calculation & Clinical Scenario Format | 45 Questions · 2-Hour Limit · NCLEX-
RN Readiness
Exam Structure
The ATI Dosage and Calculation Assessment for the 2026/2027 academic cycle is a 45-question
timed examination administered through the ATI Testing platform, consisting of multiple-choice,
fill-in-the-blank calculation, and clinical scenario items with a 2-hour time limit and standardized
scoring. Item weighting below reflects the distribution used throughout this pack.
Section Items Weighting Points
I — Metric, Household & Weight Conversions Q1–Q8 8 items × 1 pt 8 pts
II — Oral & Liquid Dosage Calculations Q9–Q16 8 items × 1 pt 8 pts
III — Parenteral Dosage & Reconstitution Q17–Q22 6 items × 1 pt 6 pts
IV — IV Flow Rates & Drop Factors Q23–Q30 8 items × 1 pt 8 pts
V — IV Piggyback & Continuous Infusions Q31–Q36 6 items × 2 pts 12 pts
VI — Pediatric & Weight-Based Dosing Q37–Q42 6 items × 2 pts 12 pts
VII — Geriatric, Safety & Clinical Judgment Q43–Q45 3 items × 2 pts 6 pts
TOTAL 45 items — 60 pts
Raw points total 60 and are reported by ATI as a percent-correct proficiency score benchmarked
to Level 2 and Level 3 standards; most programs require ≥ 90% on dosage calculation before
clinical placement.
Introduction
This guide prepares undergraduate nursing students on precise mathematical computation, safe
medication administration protocols, and clinical decision-making. The content emphasizes
dimensional analysis, ratio-proportion methods, IV infusion mathematics, weight-based dosing,
and error-prevention strategies aligned with ATI performance benchmarks, ISMP safety
guidelines, and NCLEX-RN standards, ensuring learners can accurately calculate dosages, verify
clinical appropriateness, and demonstrate competency in foundational medication safety.
ATI Testing · Dosage and Calculation Assessment · Complete Exam Pack · 2026–2027
,Core Formula Reference
The Three Calculation Methods
Method Formula When to Use
Desired over Have (D ÷ H) × Q = amount to administer Fastest for simple oral and
parenteral doses
Ratio-proportion H : Q :: D : x → cross-multiply and Useful when the relationship is
solve for x easier to see as a proportion
Dimensional analysis Order × conversion factors, arranged Most reliable for multi-step
so unwanted units cancel problems (mcg/kg/min, drip rates)
Infusion Formulas
Calculation Formula
Pump rate (mL/hr) Total volume (mL) ÷ Total time (hr)
Gravity rate (gtt/min) (mL/hr × drop factor) ÷ 60 min
IVPB rate (mL/hr) Volume × (60 ÷ minutes ordered)
Infusion time (hr) Total volume ÷ Rate (mL/hr)
Concentration Total drug ÷ Total volume
Units or mg per hour Concentration × Rate (mL/hr)
Rate from units/hr Ordered units/hr ÷ Concentration
Weight-based (mcg/kg/min) (mcg/kg/min × kg × 60) ÷ concentration in mcg/mL = mL/hr
Cockcroft-Gault CrCl [(140 − age) × kg] ÷ (72 × SCr); × 0.85 if female
Conversion Equivalents
Metric Equivalent Household / Other
1 kg 1,000 g 1 kg = 2.2 lb
1g 1,000 mg 1 tsp = 5 mL
1 mg 1,000 mcg 1 tbsp = 15 mL (3 tsp)
1L 1,000 mL 1 oz = 30 mL
1 mL 1 cc 1 cup = 8 oz = 240 mL
1 grain (gr) 60–65 mg 1 pint = 500 mL
Rounding Rules Used Throughout
• Tablets — to the nearest whole or half tablet (only scored tablets may be split).
• Oral and parenteral liquids — to the nearest tenth of a millilitre; volumes under 1 mL in
neonates, to the hundredth.
• Pump rates (mL/hr) — to the nearest whole number.
• Gravity drip rates (gtt/min) — to the nearest whole number, since a fraction of a drop cannot be
delivered.
• Round only at the final step; rounding intermediate values compounds error.
• Always use a leading zero (0.5 mg) and never a trailing zero (5 mg, not 5.0 mg).
ATI Testing · Dosage and Calculation Assessment · Complete Exam Pack · 2026–2027
, Section I · Metric, Household & Weight Conversions (Q1–Q8)
Question 1 (1 point · Fill in the Blank)
Convert 0.5 g to milligrams.
Step Set-Up Result
Identify the equivalent 1 g = 1,000 mg
Multiply (larger unit → 0.5 g × 1,000 mg/g 500 mg
smaller unit)
Correct Answer: 500 mg
Rationale: Moving from a larger metric unit to a smaller one multiplies by 1,000. Set the conversion factor
so the unwanted unit cancels: 0.5 g × (1,000 mg / 1 g) = 500 mg. A frequent error is dividing instead of
multiplying, which yields 0.0005 mg — a value so small it should immediately fail a common-sense check.
References: ATI Testing, Dosage Calculation and Safe Medication Administration 3.0; Lilley, Collins & Snyder,
Pharmacology and the Nursing Process, 10th ed. Ch. 34.
Question 2 (1 point · Fill in the Blank)
Convert 2,500 mL to liters.
Step Set-Up Result
Identify the equivalent 1 L = 1,000 mL
Divide (smaller unit → 2,500 mL ÷ 1,000 mL/L 2.5 L
larger unit)
Correct Answer: 2.5 L
Rationale: Converting from a smaller unit to a larger one divides by 1,000, so 2,500 mL becomes 2.5 L. Note
the leading zero rule does not apply here because the value exceeds 1; however, any answer less than 1 must
carry a leading zero (0.5 L, never .5 L) to prevent tenfold dosing errors.
References: ATI Testing, Dosage Calculation and Safe Medication Administration 3.0; Institute for Safe Medication
Practices (ISMP), List of Error-Prone Abbreviations and High-Alert Medications, 2024.
Question 3 (1 point · Fill in the Blank)
A client weighs 44 lb. What is the weight in kilograms?
Step Set-Up Result
Identify the equivalent 1 kg = 2.2 lb
Divide pounds by 2.2 44 lb ÷ 2.2 lb/kg 20 kg
Correct Answer: 20 kg
Rationale: Weight-based dosing is always calculated in kilograms, so pounds must be converted first: 44 ÷
2.2 = 20 kg. Multiplying by 2.2 instead would give 96.8 kg, more than four times the true weight — the single
most consequential conversion error in pediatric practice.
References: ATI Testing, Dosage Calculation and Safe Medication Administration 3.0; Institute for Safe Medication
Practices (ISMP), List of Error-Prone Abbreviations and High-Alert Medications, 2024; Lilley, Collins & Snyder,
Pharmacology and the Nursing Process, 10th ed. Ch. 34.
ATI Testing · Dosage and Calculation Assessment · Complete Exam Pack · 2026–2027
