Dosage Calculations Workbook: Step-by-Step Examples &
Practice
Questions with Verified Answers
Table of Contents
1. Basic Formula & Ratio-Proportion
2. Oral Medications
3. Injectable Medications
4. IV Flow Rates & Infusion Calculations
5. Pediatric & Weight-Based Dosing
6. Unit Conversions
7. Complex Multi-Step Problems
Basic Formulas & Key Concepts {#basic-formulas}
Essential Formulas
Basic Formula:
Desired Dose (D) × Quantity (Q) = Amount to Give
Available Dose (H)
Ratio-Proportion:
Known : Known :: Unknown : Unknown
Have : Vehicle :: Want : X
,Dimensional Analysis:
What you want × Conversion factors = Answer
What you have
Section 1: Basic Oral Medications (Questions 1-20)
Question 1
Order: Digoxin 0.25 mg PO daily Available: Digoxin 0.125 mg tablets
How many tablets will you administer?
Step-by-Step Solution:
• D (Desired) = 0.25 mg
• H (Have) = 0.125 mg
• Q (Quantity) = 1 tablet
Using formula: D/H × Q = X 0.25 mg ÷ 0.125 mg × 1 tablet = 2 tablets
Answer: 2 tablets
Question 2
Order: Amoxicillin 500 mg PO q8h Available: Amoxicillin 250 mg
capsules How many capsules per dose?
Solution: 500 mg ÷ 250 mg × 1 capsule = 2 capsules
Answer: 2 capsules
Question 3
Order: Furosemide 40 mg PO BID Available: Furosemide 20 mg tablets
How many tablets for the morning dose?
, Solution: 40 mg ÷ 20 mg × 1 tablet = 2 tablets
Answer: 2 tablets
Question 4
Order: Levothyroxine 0.075 mg PO daily Available: Levothyroxine 75
mcg tablets How many tablets will you give?
Solution: First convert: 0.075 mg = 75 mcg 75 mcg ÷ 75 mcg × 1 tablet =
1 tablet
Answer: 1 tablet
Question 5
Order: Metformin 1 gram PO BID Available: Metformin 500 mg tablets
How many tablets per dose?
Solution: Convert: 1 gram = 1,000 mg 1,000 mg ÷ 500 mg × 1 tablet = 2
tablets
Answer: 2 tablets
Question 6
Order: Hydrochlorothiazide 25 mg PO daily Available:
Hydrochlorothiazide 12.5 mg tablets How many tablets will you
administer?
Solution: 25 mg ÷ 12.5 mg × 1 tablet = 2 tablets
Answer: 2 tablets
Question 7
Order: Prednisone 7.5 mg PO daily Available: Prednisone 2.5 mg tablets
How many tablets should be given?
Practice
Questions with Verified Answers
Table of Contents
1. Basic Formula & Ratio-Proportion
2. Oral Medications
3. Injectable Medications
4. IV Flow Rates & Infusion Calculations
5. Pediatric & Weight-Based Dosing
6. Unit Conversions
7. Complex Multi-Step Problems
Basic Formulas & Key Concepts {#basic-formulas}
Essential Formulas
Basic Formula:
Desired Dose (D) × Quantity (Q) = Amount to Give
Available Dose (H)
Ratio-Proportion:
Known : Known :: Unknown : Unknown
Have : Vehicle :: Want : X
,Dimensional Analysis:
What you want × Conversion factors = Answer
What you have
Section 1: Basic Oral Medications (Questions 1-20)
Question 1
Order: Digoxin 0.25 mg PO daily Available: Digoxin 0.125 mg tablets
How many tablets will you administer?
Step-by-Step Solution:
• D (Desired) = 0.25 mg
• H (Have) = 0.125 mg
• Q (Quantity) = 1 tablet
Using formula: D/H × Q = X 0.25 mg ÷ 0.125 mg × 1 tablet = 2 tablets
Answer: 2 tablets
Question 2
Order: Amoxicillin 500 mg PO q8h Available: Amoxicillin 250 mg
capsules How many capsules per dose?
Solution: 500 mg ÷ 250 mg × 1 capsule = 2 capsules
Answer: 2 capsules
Question 3
Order: Furosemide 40 mg PO BID Available: Furosemide 20 mg tablets
How many tablets for the morning dose?
, Solution: 40 mg ÷ 20 mg × 1 tablet = 2 tablets
Answer: 2 tablets
Question 4
Order: Levothyroxine 0.075 mg PO daily Available: Levothyroxine 75
mcg tablets How many tablets will you give?
Solution: First convert: 0.075 mg = 75 mcg 75 mcg ÷ 75 mcg × 1 tablet =
1 tablet
Answer: 1 tablet
Question 5
Order: Metformin 1 gram PO BID Available: Metformin 500 mg tablets
How many tablets per dose?
Solution: Convert: 1 gram = 1,000 mg 1,000 mg ÷ 500 mg × 1 tablet = 2
tablets
Answer: 2 tablets
Question 6
Order: Hydrochlorothiazide 25 mg PO daily Available:
Hydrochlorothiazide 12.5 mg tablets How many tablets will you
administer?
Solution: 25 mg ÷ 12.5 mg × 1 tablet = 2 tablets
Answer: 2 tablets
Question 7
Order: Prednisone 7.5 mg PO daily Available: Prednisone 2.5 mg tablets
How many tablets should be given?
