Pediatric GFR Calculator (Glomerular Filtration Rate)

Estimate kidney function in children using the Schwartz formula. Enter height, serum creatinine, age, and gender to calculate pediatric GFR.

This calculator uses the Schwartz formula to estimate the glomerular filtration rate (GFR) in children. GFR is a key indicator of kidney function and is essential for diagnosing and monitoring chronic kidney disease (CKD) in pediatric patients. Enter the required values to get an accurate assessment of renal function.

Examples

Click on any example to load it into the calculator.

School-age child, normal kidney function

School-age Child

8-year-old boy, 130 cm tall, serum creatinine 0.6 mg/dL.

Height: 130 cm

Serum Creatinine: 0.6 mg/dL

Age: 8 years

Gender: Female

Adolescent girl, mild decrease

Adolescent

15-year-old girl, 160 cm, serum creatinine 1.0 mg/dL.

Height: 160 cm

Serum Creatinine: 1 mg/dL

Age: 15 years

Gender: Female

Preschool child, moderate decrease

Preschool Child

4-year-old boy, 100 cm, serum creatinine 1.5 mg/dL.

Height: 100 cm

Serum Creatinine: 1.5 mg/dL

Age: 4 years

Gender: Female

Infant, severe decrease (µmol/L)

Infant (µmol/L)

1-year-old girl, 75 cm, serum creatinine 120 µmol/L.

Height: 75 cm

Serum Creatinine: 120 umol/L

Age: 1 years

Gender: Female

Other Titles
Understanding Pediatric GFR Calculator: A Comprehensive Guide
Master the estimation of glomerular filtration rate in children. Learn the science, application, and interpretation of pediatric GFR for optimal kidney health.

What is Pediatric GFR and Why is it Important?

  • Definition and Clinical Relevance
  • Kidney Function in Children
  • Role in Chronic Kidney Disease (CKD)
Glomerular Filtration Rate (GFR) is the best overall indicator of kidney function. In children, accurate GFR estimation is crucial for diagnosing, staging, and monitoring chronic kidney disease (CKD). Pediatric GFR calculators use formulas tailored to children's physiology, most commonly the Schwartz formula, to provide reliable estimates based on height and serum creatinine.
Why GFR Matters in Pediatrics
Children's kidneys are still developing, and early detection of reduced GFR can prevent progression to kidney failure. GFR guides medication dosing, nutrition, and treatment planning in pediatric nephrology.
CKD Staging in Children
CKD is staged based on GFR values. Early identification allows for timely intervention, slowing disease progression and improving outcomes.

Key GFR Ranges:

  • Normal: ≥90 mL/min/1.73 m²
  • Mild decrease: 60–89 mL/min/1.73 m²
  • Moderate decrease: 30–59 mL/min/1.73 m²
  • Severe decrease: 15–29 mL/min/1.73 m²
  • Kidney failure: <15 mL/min/1.73 m²

Step-by-Step Guide to Using the Pediatric GFR Calculator

  • Collecting Accurate Data
  • Inputting Values Correctly
  • Interpreting Results
To use the Pediatric GFR Calculator, gather the child's height (in cm), serum creatinine (mg/dL or µmol/L), age (years), and gender. Enter these values into the calculator. The tool automatically applies the Schwartz formula and converts units as needed.
Data Entry Tips
Ensure height is measured accurately, as errors can significantly affect GFR estimation. Use the most recent and reliable serum creatinine value.
Understanding the Output
The result includes the estimated GFR, the CKD stage, and the formula used. Use this information to guide further clinical decisions or discussions with a healthcare provider.

Example Inputs:

  • Height: 120 cm, Creatinine: 0.7 mg/dL, Age: 10, Gender: Male
  • Height: 90 cm, Creatinine: 1.2 mg/dL, Age: 3, Gender: Female

Real-World Applications of Pediatric GFR Calculation

  • Clinical Practice
  • Medication Dosing
  • Research and Epidemiology
Pediatric GFR estimation is used in clinics to diagnose and monitor kidney disease, adjust medication dosages, and assess overall kidney health. It is also vital in research studies and public health initiatives focused on pediatric renal health.
Medication Dosing
Many drugs are cleared by the kidneys. Accurate GFR estimation ensures safe and effective dosing in children, reducing the risk of toxicity or underdosing.
Population Health
Epidemiological studies use GFR data to track kidney disease prevalence and outcomes in pediatric populations.

Clinical Scenarios:

  • Adjusting antibiotic dose in a child with reduced GFR
  • Screening for CKD in children with risk factors

Common Misconceptions and Correct Methods

  • Myths about GFR Calculation
  • Pitfalls in Data Collection
  • Best Practices
A common misconception is that adult GFR formulas can be used for children. Pediatric formulas account for differences in body size and development. Another pitfall is using outdated or inaccurate creatinine measurements.
Avoiding Errors
Always use the correct units and the most recent lab values. Double-check height and creatinine entries before calculating.
Best Practices
Use the Schwartz formula for most children. For infants or special populations, consult a pediatric nephrologist for alternative methods if needed.

Best Practice Tips:

  • Always measure height in centimeters
  • Convert creatinine units if needed before calculation

Mathematical Derivation and Example Calculations

  • The Schwartz Formula
  • Unit Conversions
  • Worked Examples
The Schwartz formula is the most widely used equation for estimating GFR in children: GFR = (k × Height) / Serum Creatinine. The constant k is typically 0.413 for most children.
Unit Conversion
If serum creatinine is reported in µmol/L, convert to mg/dL by dividing by 88.4. Always use consistent units in the formula.
Example Calculation
For a 10-year-old boy, height 140 cm, serum creatinine 0.7 mg/dL: GFR = (0.413 × 140) / 0.7 = 82.6 mL/min/1.73 m². This falls in the 'mild decrease' category.

Sample Calculations:

  • Height: 140 cm, Creatinine: 0.7 mg/dL, GFR: 82.6 mL/min/1.73 m²
  • Height: 75 cm, Creatinine: 120 µmol/L, GFR: 0.413 × 75 / (120/88.4) = 22.8 mL/min/1.73 m²