Pharmacy Calculations Review 2026–2027
Pharmacy Calculations Review 2026–2027 | Dosage, Conversions
& Practice Problems
Dosage, Conversions & Practice Problems
Question 1
The provider orders amoxicillin 500 mg PO. The label reads
250 mg/5 mL. How many mL will the nurse administer?
A. 5 mL
B. 10 mL
C. 15 mL
D. 20 mL
Correct answer: B. 10 mL
Rationale: (500 mg ÷ 250 mg) × 5 mL = 2 × 5 mL = 10
mL. The ordered dose is twice the strength in each 5 mL, so twice the volume is
needed.
Why the Other Options Are Incorrect:
A. 5 mL delivers only 250 mg (half the ordered dose).
C. 15 mL delivers 750 mg (overdose).
D. 20 mL delivers 1,000 mg, double the ordered dose.
Question 2
A child weighing 44 lb is prescribed a medication at 15
mg/kg/day divided every 8 hours. How many mg are given per dose?
A. 100 mg
B. 150 mg
C. 300 mg
D. 660 mg
Correct answer: A. 100 mg
Rationale: 44 lb ÷ 2.2 = 20 kg. Daily dose = 15 mg ×
20 kg = 300 mg/day. Every 8 hours means 3 doses/day: 300 ÷ 3 = 100 mg per dose.
Why the Other Options Are Incorrect:
B. 150 mg assumes two doses per day (every 12 hours).
C. 300 mg is the total daily dose, not the single dose.
D. 660 mg results from multiplying 15 mg by the weight in
pounds instead of kilograms.
Question 3
Order: 1,000 mL 0.9% sodium chloride IV over 8 hours via
infusion pump. At what rate (mL/hr) should the pump be set?
A. 100 mL/hr
B. 125 mL/hr
C. 133 mL/hr
D. 150 mL/hr
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, Pharmacy Calculations Review 2026–2027
Correct answer: B. 125 mL/hr
Rationale: 1,000 mL ÷ 8 hr = 125 mL/hr.
Why the Other Options Are Incorrect:
A. 100 mL/hr would take 10 hours to infuse the bag.
C. 133 mL/hr would finish in about 7.5 hours.
D. 150 mL/hr would finish in about 6.7 hours.
Question 4
Order: 500 mL IV fluid over 4 hours by gravity. The drop
factor is 15 gtt/mL. What is the drip rate in gtt/min (round to the nearest
whole number)?
A. 21 gtt/min
B. 31 gtt/min
C. 42 gtt/min
D. 125 gtt/min
Correct answer: B. 31 gtt/min
Rationale: 4 hr = 240 min. (500 mL × 15 gtt/mL) ÷ 240
min = 7,500 ÷ 240 = 31.25, rounded to 31 gtt/min.
Why the Other Options Are Incorrect:
A. 21 gtt/min results from using a 10 gtt/mL drop factor.
C. 42 gtt/min results from using a 20 gtt/mL drop factor.
D. 125 is the rate in mL/hr (500 ÷ 4), not drops per minute.
Question 5
Heparin 25,000 units in 250 mL D5W is infusing. The order is
1,200 units/hr. At what rate (mL/hr) should the pump be set?
A. 1.2 mL/hr
B. 8 mL/hr
C. 12 mL/hr
D. 120 mL/hr
Correct answer: C. 12 mL/hr
Rationale: Concentration = 25,000 units ÷ 250 mL =
100 units/mL. Rate = 1,200 units/hr ÷ 100 units/mL = 12 mL/hr.
Why the Other Options Are Incorrect:
A. 1.2 mL/hr is a decimal error and would deliver only 120
units/hr.
B. 8 mL/hr would deliver only 800 units/hr (underdose).
D. 120 mL/hr is a tenfold decimal error and would deliver
12,000 units/hr, a dangerous overdose.
Question 6
Convert digoxin 0.25 mg to micrograms (mcg).
A. 2.5 mcg
B. 25 mcg
Pharmacy Calculations Review 2026–2027 | Practice Resource • Page 2
, Pharmacy Calculations Review 2026–2027
C. 250 mcg
D. 2,500 mcg
Correct answer: C. 250 mcg
Rationale: 1 mg = 1,000 mcg, so 0.25 mg × 1,000 = 250
mcg (move the decimal three places right).
Why the Other Options Are Incorrect:
A. 2.5 mcg moves the decimal only one place.
B. 25 mcg moves the decimal only two places.
D. 2,500 mcg moves the decimal four places (tenfold
overdose).
Question 7
The order is levothyroxine 0.1 mg PO daily. Tablets
available are 50 mcg. How many tablets should the nurse give?
A. ½ tablet
B. 1 tablet
C. 2 tablets
D. 4 tablets
Correct answer: C. 2 tablets
Rationale: 0.1 mg = 100 mcg. 100 mcg ÷ 50 mcg per
tablet = 2 tablets.
Why the Other Options Are Incorrect:
A. ½ tablet gives only 25 mcg.
B. 1 tablet gives only 50 mcg (half the dose).
D. 4 tablets give 200 mcg, double the ordered dose,
typically from a unit-conversion error.
Question 8
The order is morphine sulfate 4 mg IV push. The vial
contains 10 mg/mL. How many mL will the nurse draw up?
A. 0.25 mL
B. 0.4 mL
C. 2.5 mL
D. 4 mL
Correct answer: B. 0.4 mL
Rationale: (4 mg ÷ 10 mg) × 1 mL = 0.4 mL.
Why the Other Options Are Incorrect:
A. 0.25 mL delivers 2.5 mg (underdose).
C. 2.5 mL results from inverting the fraction (10 ÷ 4) and
would deliver 25 mg, a serious overdose.
D. 4 mL treats milligrams as milliliters and would deliver
40 mg.
Question 9
A child weighing 33 lb needs acetaminophen 15 mg/kg/dose.
Pharmacy Calculations Review 2026–2027 | Practice Resource • Page 3
Pharmacy Calculations Review 2026–2027 | Dosage, Conversions
& Practice Problems
Dosage, Conversions & Practice Problems
Question 1
The provider orders amoxicillin 500 mg PO. The label reads
250 mg/5 mL. How many mL will the nurse administer?
A. 5 mL
B. 10 mL
C. 15 mL
D. 20 mL
Correct answer: B. 10 mL
Rationale: (500 mg ÷ 250 mg) × 5 mL = 2 × 5 mL = 10
mL. The ordered dose is twice the strength in each 5 mL, so twice the volume is
needed.
Why the Other Options Are Incorrect:
A. 5 mL delivers only 250 mg (half the ordered dose).
C. 15 mL delivers 750 mg (overdose).
D. 20 mL delivers 1,000 mg, double the ordered dose.
Question 2
A child weighing 44 lb is prescribed a medication at 15
mg/kg/day divided every 8 hours. How many mg are given per dose?
A. 100 mg
B. 150 mg
C. 300 mg
D. 660 mg
Correct answer: A. 100 mg
Rationale: 44 lb ÷ 2.2 = 20 kg. Daily dose = 15 mg ×
20 kg = 300 mg/day. Every 8 hours means 3 doses/day: 300 ÷ 3 = 100 mg per dose.
Why the Other Options Are Incorrect:
B. 150 mg assumes two doses per day (every 12 hours).
C. 300 mg is the total daily dose, not the single dose.
D. 660 mg results from multiplying 15 mg by the weight in
pounds instead of kilograms.
Question 3
Order: 1,000 mL 0.9% sodium chloride IV over 8 hours via
infusion pump. At what rate (mL/hr) should the pump be set?
A. 100 mL/hr
B. 125 mL/hr
C. 133 mL/hr
D. 150 mL/hr
Pharmacy Calculations Review 2026–2027 | Practice Resource • Page 1
, Pharmacy Calculations Review 2026–2027
Correct answer: B. 125 mL/hr
Rationale: 1,000 mL ÷ 8 hr = 125 mL/hr.
Why the Other Options Are Incorrect:
A. 100 mL/hr would take 10 hours to infuse the bag.
C. 133 mL/hr would finish in about 7.5 hours.
D. 150 mL/hr would finish in about 6.7 hours.
Question 4
Order: 500 mL IV fluid over 4 hours by gravity. The drop
factor is 15 gtt/mL. What is the drip rate in gtt/min (round to the nearest
whole number)?
A. 21 gtt/min
B. 31 gtt/min
C. 42 gtt/min
D. 125 gtt/min
Correct answer: B. 31 gtt/min
Rationale: 4 hr = 240 min. (500 mL × 15 gtt/mL) ÷ 240
min = 7,500 ÷ 240 = 31.25, rounded to 31 gtt/min.
Why the Other Options Are Incorrect:
A. 21 gtt/min results from using a 10 gtt/mL drop factor.
C. 42 gtt/min results from using a 20 gtt/mL drop factor.
D. 125 is the rate in mL/hr (500 ÷ 4), not drops per minute.
Question 5
Heparin 25,000 units in 250 mL D5W is infusing. The order is
1,200 units/hr. At what rate (mL/hr) should the pump be set?
A. 1.2 mL/hr
B. 8 mL/hr
C. 12 mL/hr
D. 120 mL/hr
Correct answer: C. 12 mL/hr
Rationale: Concentration = 25,000 units ÷ 250 mL =
100 units/mL. Rate = 1,200 units/hr ÷ 100 units/mL = 12 mL/hr.
Why the Other Options Are Incorrect:
A. 1.2 mL/hr is a decimal error and would deliver only 120
units/hr.
B. 8 mL/hr would deliver only 800 units/hr (underdose).
D. 120 mL/hr is a tenfold decimal error and would deliver
12,000 units/hr, a dangerous overdose.
Question 6
Convert digoxin 0.25 mg to micrograms (mcg).
A. 2.5 mcg
B. 25 mcg
Pharmacy Calculations Review 2026–2027 | Practice Resource • Page 2
, Pharmacy Calculations Review 2026–2027
C. 250 mcg
D. 2,500 mcg
Correct answer: C. 250 mcg
Rationale: 1 mg = 1,000 mcg, so 0.25 mg × 1,000 = 250
mcg (move the decimal three places right).
Why the Other Options Are Incorrect:
A. 2.5 mcg moves the decimal only one place.
B. 25 mcg moves the decimal only two places.
D. 2,500 mcg moves the decimal four places (tenfold
overdose).
Question 7
The order is levothyroxine 0.1 mg PO daily. Tablets
available are 50 mcg. How many tablets should the nurse give?
A. ½ tablet
B. 1 tablet
C. 2 tablets
D. 4 tablets
Correct answer: C. 2 tablets
Rationale: 0.1 mg = 100 mcg. 100 mcg ÷ 50 mcg per
tablet = 2 tablets.
Why the Other Options Are Incorrect:
A. ½ tablet gives only 25 mcg.
B. 1 tablet gives only 50 mcg (half the dose).
D. 4 tablets give 200 mcg, double the ordered dose,
typically from a unit-conversion error.
Question 8
The order is morphine sulfate 4 mg IV push. The vial
contains 10 mg/mL. How many mL will the nurse draw up?
A. 0.25 mL
B. 0.4 mL
C. 2.5 mL
D. 4 mL
Correct answer: B. 0.4 mL
Rationale: (4 mg ÷ 10 mg) × 1 mL = 0.4 mL.
Why the Other Options Are Incorrect:
A. 0.25 mL delivers 2.5 mg (underdose).
C. 2.5 mL results from inverting the fraction (10 ÷ 4) and
would deliver 25 mg, a serious overdose.
D. 4 mL treats milligrams as milliliters and would deliver
40 mg.
Question 9
A child weighing 33 lb needs acetaminophen 15 mg/kg/dose.
Pharmacy Calculations Review 2026–2027 | Practice Resource • Page 3
