What Is the Glomerular Filtration Rate (2021 CKD-EPI) Calculator?
eGFR estimates the filtration rate of blood through the glomeruli of the kidneys in mL/min/1.73m².
How Does the Glomerular Filtration Rate (2021 CKD-EPI) Calculator Work?
Applies sex-specific spline thresholds κ (0.7 for female, 0.9 for male) and exponents α.
Adjusts for age-related nephron loss using exponential factor 0.9938^Age.
Glomerular Filtration Rate (2021 CKD-EPI) Calculator Formula & Variables
The core mathematical equation utilized by this calculator is expressed as:
eGFR = 142 · min(Scr/κ, 1)^α · max(Scr/κ, 1)^(-1.200) · 0.9938^Age · (1.012 if female)
2021 CKD-EPI race-free equation endorsed by NKF-ASN task force and KDIGO.
How to Use the Glomerular Filtration Rate (2021 CKD-EPI) Calculator
- Enter serum creatinine, age, and sex.
- Inspect eGFR value and corresponding CKD stage.
Step-by-Step Example Calculation
Adult Male Renal Assessment
Input Values:
serumCreatinine:1
age:50
sex:male
Worked Steps: 50-year-old male with 1.0 mg/dL serum creatinine.
Understanding Your Result
eGFR >= 90 is normal (Stage G1).
eGFR < 60 indicates chronic kidney disease when sustained > 3 months.
eGFR < 15 indicates kidney failure (Stage G5).
Factors That Affect the Result
- Extreme muscle mass (bodybuilders or amputees).
- Dietary creatine intake.
When Should You Use This Calculator?
- Screening, diagnosing, and monitoring chronic kidney disease and drug dosing adjustment.
Assumptions & Limitations
- Assumes stable kidney function; not validated in acute kidney injury (AKI).
Frequently Asked Questions
Calculation Accuracy & Reference Note
KDIGO 2021 guideline implementation.