eGFR Calculator (CKD-EPI 2021)
Calculate estimated Glomerular Filtration Rate to assess kidney function.
Male
Female
Standard range: 0.6 – 1.3 mg/dL
mg/dL (Standard US)
µmol/L (International)
Estimated Glomerular Filtration Rate
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mL/min/1.73m²
Stage —
Enter your details above to see the interpretation.
Understanding Glomerular Filtration Rate (GFR)
The Glomerular Filtration Rate (GFR) is widely considered the best overall index of kidney function in health and disease. Since GFR is difficult to measure directly in clinical practice, it is estimated (eGFR) using equations that include serum creatinine levels, age, and gender.
The CKD-EPI 2021 Equation
This calculator uses the 2021 CKD-EPI Creatinine Equation. This is currently the recommended formula by the National Kidney Foundation and the American Society of Nephrology. It was developed to provide an accurate estimate of kidney function without including a coefficient for race, reducing bias in medical diagnosis.
Chronic Kidney Disease (CKD) Stages
Kidney function is categorized into five stages based on the eGFR value. A lower number indicates reduced kidney function.
| Stage | eGFR (mL/min/1.73m²) | Description |
|---|---|---|
| Stage 1 | 90 or higher | Normal or high kidney function (often with other signs of kidney damage). |
| Stage 2 | 60 – 89 | Mildly decreased kidney function. |
| Stage 3a | 45 – 59 | Mild to moderately decreased kidney function. |
| Stage 3b | 30 – 44 | Moderately to severely decreased kidney function. |
| Stage 4 | 15 – 29 | Severely decreased kidney function. |
| Stage 5 | Less than 15 | Kidney failure (End Stage Renal Disease). |
When to Consult a Doctor
An eGFR below 60 mL/min/1.73m² for more than three months is a diagnostic criterion for Chronic Kidney Disease (CKD). If your calculated result falls below 60, or if you have risk factors such as diabetes, high blood pressure, or a family history of kidney failure, it is crucial to consult with a healthcare professional for comprehensive testing and diagnosis.
Factors Affecting Creatinine Levels
Since eGFR is based on serum creatinine, factors that affect muscle mass can influence the result:
- Muscle Mass: Bodybuilders may have higher creatinine (lower eGFR) without kidney disease; amputees or those with muscle wasting may have lower creatinine (higher eGFR).
- Diet: High protein intake (cooked meat) can temporarily raise creatinine.
- Medications: Certain drugs can alter creatinine secretion.