PEDIATRIC DOSAGE
CALCULATION PRACTICE BANK
& FORMULA GUIDE
,SECTION 1 — PEDIATRIC
FORMULAS
1. Weight-Based Drug Dosage
Formula 1 — Single Dose Calculation
Dose (mg) = Weight (kg) × Ordered dose (mg/kg)
Example:
• Child weight: 15 kg
• Ordered: 10 mg/kg
Dose = 15 × 10 = 150 mg
Formula 2 — Daily Dose Divided by Frequency
Total daily dose (mg)
Dose per administration =
Number of doses/day
Example:
• Total daily dose: 300 mg
• Frequency: q8h (3 times/day)
300
Dose per administration = = 100 mg/dose
3
,Formula 3 — Clark’s Rule (Alternative for Age)
Weight (lb)
Child’s dose = × Adult dose
150
Formula 4 — Young’s Rule (Age-Based)
Age (years)
Child’s dose = × Adult dose
Age + 12
2. Fluid Maintenance Calculation (Holliday-Segar
Method)
Weight Maintenance Fluid
0–10 kg 100 mL/kg/day
11–20 kg 1000 mL + 50 mL/kg for each kg >10
>20 kg 1500 mL + 20 mL/kg for each kg >20
Example:
• Weight: 25 kg
• Maintenance: 1500 + (20 × 5) = 1500 + 100 = 1600 mL/day
3. IV Drip Rate Calculation
Total volume (mL)
Flow rate (mL/hr) =
Time (hr)
Total volume (mL) × Drop factor (gtt/mL)
Flow rate (gtt/min) =
Time (min)
, 4. Pediatric Vital Signs (Age-Specific Reference)
RR Temp
Age HR (bpm) BP (mmHg)
(breaths/min) (°C)
Newborn 100–180 30–60 60––60 36.5–37.5
Infant (1–12 mo) 100–160 30–53 70––65 36.5–37.5
Toddler (1–3 yr) 90–150 22–37 80––70 36.5–37.5
Preschool (3–5 yr) 80–140 20–28 85––80 36.5–37.5
School-age (6–12 yr) 75–120 18–25 90––75 36.5–37.5
Adolescent (13–18 yr) 60–100 12–20 110––85 36.5–37.5
SECTION 2 — PRACTICE PROBLEMS
(WEIGHT-BASED DOSAGE)
Problem 1
• Weight: 12 kg
• Ordered: Amoxicillin 50 mg/kg/day, divided q8h
Calculate dose per administration.
Problem 2
• Weight: 18 kg
• Ordered: Acetaminophen 15 mg/kg/dose q6h PRN
Calculate dose per administration.
, Problem 3
• Weight: 7 kg
• Ordered: Ceftriaxone 80 mg/kg/day IV q12h
Calculate single dose.
Problem 4
• Weight: 25 kg
• Ordered: Ibuprofen 10 mg/kg/dose q6h PRN
Calculate per dose.
Problem 5
• Weight: 5 kg
• Ordered: Digoxin 0.01 mg/kg/day, divided BID
Calculate per dose.
Problem 6 (IV Fluid Maintenance)
• Weight: 15 kg
• Calculate daily maintenance fluid and mL/hr.
Problem 7
• Weight: 22 kg
• Ordered: Cefazolin 25 mg/kg IV q8h
Calculate dose per administration.
Problem 8
CALCULATION PRACTICE BANK
& FORMULA GUIDE
,SECTION 1 — PEDIATRIC
FORMULAS
1. Weight-Based Drug Dosage
Formula 1 — Single Dose Calculation
Dose (mg) = Weight (kg) × Ordered dose (mg/kg)
Example:
• Child weight: 15 kg
• Ordered: 10 mg/kg
Dose = 15 × 10 = 150 mg
Formula 2 — Daily Dose Divided by Frequency
Total daily dose (mg)
Dose per administration =
Number of doses/day
Example:
• Total daily dose: 300 mg
• Frequency: q8h (3 times/day)
300
Dose per administration = = 100 mg/dose
3
,Formula 3 — Clark’s Rule (Alternative for Age)
Weight (lb)
Child’s dose = × Adult dose
150
Formula 4 — Young’s Rule (Age-Based)
Age (years)
Child’s dose = × Adult dose
Age + 12
2. Fluid Maintenance Calculation (Holliday-Segar
Method)
Weight Maintenance Fluid
0–10 kg 100 mL/kg/day
11–20 kg 1000 mL + 50 mL/kg for each kg >10
>20 kg 1500 mL + 20 mL/kg for each kg >20
Example:
• Weight: 25 kg
• Maintenance: 1500 + (20 × 5) = 1500 + 100 = 1600 mL/day
3. IV Drip Rate Calculation
Total volume (mL)
Flow rate (mL/hr) =
Time (hr)
Total volume (mL) × Drop factor (gtt/mL)
Flow rate (gtt/min) =
Time (min)
, 4. Pediatric Vital Signs (Age-Specific Reference)
RR Temp
Age HR (bpm) BP (mmHg)
(breaths/min) (°C)
Newborn 100–180 30–60 60––60 36.5–37.5
Infant (1–12 mo) 100–160 30–53 70––65 36.5–37.5
Toddler (1–3 yr) 90–150 22–37 80––70 36.5–37.5
Preschool (3–5 yr) 80–140 20–28 85––80 36.5–37.5
School-age (6–12 yr) 75–120 18–25 90––75 36.5–37.5
Adolescent (13–18 yr) 60–100 12–20 110––85 36.5–37.5
SECTION 2 — PRACTICE PROBLEMS
(WEIGHT-BASED DOSAGE)
Problem 1
• Weight: 12 kg
• Ordered: Amoxicillin 50 mg/kg/day, divided q8h
Calculate dose per administration.
Problem 2
• Weight: 18 kg
• Ordered: Acetaminophen 15 mg/kg/dose q6h PRN
Calculate dose per administration.
, Problem 3
• Weight: 7 kg
• Ordered: Ceftriaxone 80 mg/kg/day IV q12h
Calculate single dose.
Problem 4
• Weight: 25 kg
• Ordered: Ibuprofen 10 mg/kg/dose q6h PRN
Calculate per dose.
Problem 5
• Weight: 5 kg
• Ordered: Digoxin 0.01 mg/kg/day, divided BID
Calculate per dose.
Problem 6 (IV Fluid Maintenance)
• Weight: 15 kg
• Calculate daily maintenance fluid and mL/hr.
Problem 7
• Weight: 22 kg
• Ordered: Cefazolin 25 mg/kg IV q8h
Calculate dose per administration.
Problem 8
