eGFR Calculator (CKD-EPI 2021 Equation)
Important Medical Disclaimer
This eGFR calculator is intended for informational purposes only and should NOT be used as a substitute for professional medical advice, diagnosis, or treatment. The results are estimates based on a standard formula and require interpretation by a qualified healthcare provider in the context of your individual health status and medical history.
Do not make any medical decisions based solely on the results from this calculator. Always consult your doctor or another qualified health provider with any questions you may have regarding a medical condition or your kidney health.
Estimate your Glomerular Filtration Rate (eGFR), a key measure of kidney function, using the 2021 CKD-EPI Creatinine equation. Enter your serum creatinine level, age, and sex assigned at birth.
Calculate Your eGFR
What is eGFR?
Estimated Glomerular Filtration Rate (eGFR) is a calculation based on a blood test for creatinine, your age, and sex. It provides an estimate of how much blood your kidneys filter per minute, standardized to a typical body surface area (mL/min/1.73m²). Healthy kidneys filter waste products efficiently, resulting in a higher eGFR. A lower eGFR suggests the kidneys may not be working as well as they should.
The CKD-EPI 2021 Creatinine Equation
This calculator uses the formula developed by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and updated in 2021. This version is recommended by the National Kidney Foundation (NKF) and the American Society of Nephrology (ASN) because it provides an accurate estimate without using a race coefficient, addressing health equity concerns associated with older formulas.
The formula requires:
- Serum Creatinine: A waste product measured in your blood (mg/dL or µmol/L).
- Age: In years.
- Sex: Sex assigned at birth (Male/Female), as it influences muscle mass and creatinine levels.
Interpreting Your eGFR Result
eGFR results help healthcare providers assess kidney function and stage Chronic Kidney Disease (CKD). Remember, interpretation requires clinical context.
| CKD Stage | eGFR (mL/min/1.73m²) | Description |
|---|---|---|
| Stage 1 | ≥ 90 | Normal or high GFR (requires other signs of kidney damage like protein in urine for CKD diagnosis) |
| Stage 2 | 60–89 | Mildly decreased GFR (requires other signs of kidney damage for CKD diagnosis) |
| Stage 3a | 45–59 | Mildly to moderately decreased GFR |
| Stage 3b | 30–44 | Moderately to severely decreased GFR |
| Stage 4 | 15–29 | Severely decreased GFR |
| Stage 5 | < 15 | Kidney Failure (End-Stage Renal Disease, ESRD) |
Important: A single eGFR result below 60 mL/min/1.73m² does not automatically mean you have CKD. Kidney function can fluctuate. Diagnosis requires confirmation, often with repeat testing over 3 months and consideration of other factors by your doctor.
Frequently Asked Questions (FAQ)
What is eGFR (Estimated Glomerular Filtration Rate)?
eGFR is an estimate of how well your kidneys are filtering waste products (like creatinine) from your blood. It's a key indicator of kidney function, measured in mL/min/1.73m².
How does this calculator estimate GFR?
This calculator uses the 2021 CKD-EPI Creatinine equation, which is the current standard recommended by major kidney organizations. It estimates GFR based on your serum creatinine level (from a blood test), age, and sex assigned at birth. Importantly, the 2021 version no longer uses race as a variable.
Why is monitoring eGFR important?
Monitoring eGFR helps detect kidney disease in its early stages, often before symptoms appear. Early detection allows for timely intervention to slow the progression of kidney damage and manage related health complications like high blood pressure and heart disease.
What do the eGFR results mean?
eGFR results are typically categorized into stages of Chronic Kidney Disease (CKD): Stage 1 (≥90, normal or high with kidney damage signs), Stage 2 (60-89, mild decrease), Stage 3a (45-59, mild-moderate decrease), Stage 3b (30-44, moderate-severe decrease), Stage 4 (15-29, severe decrease), Stage 5 (<15, kidney failure). Interpretation requires clinical context.
Is this calculator a substitute for professional medical advice?
Absolutely not. This calculator provides an estimate for informational purposes only. It cannot diagnose kidney disease. Always discuss your eGFR results and kidney health with a qualified healthcare professional who can consider your full medical history and perform necessary evaluations.