eGFR Calculator (CKD-EPI) — Free Online Calculator
Input
eGFR (2021 CKD-EPI, race-free)
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About This Calculator
The estimated glomerular filtration rate (eGFR) is used to assess kidney function. The CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) equation is the most widely recommended formula. In 2021, the CKD-EPI equation was updated to remove the race variable, providing a single equation for all patients. The 2009 version with race adjustment is provided for reference only.
Formula
Interpretation
| GFR Stage | eGFR (mL/min/1.73m²) | Description |
|---|---|---|
| G1 | ≥ 90 | Normal or high |
| G2 | 60 – 89 | Mildly decreased |
| G3a | 45 – 59 | Mildly to moderately decreased |
| G3b | 30 – 44 | Moderately to severely decreased |
| G4 | 15 – 29 | Severely decreased |
| G5 | < 15 | Kidney failure |
References
- Inker LA, et al. New Creatinine- and Cystatin C-Based Equations to Estimate GFR without Race. N Engl J Med. 2021;385(19):1737-1749.
- Levey AS, et al. A new equation to estimate glomerular filtration rate. Ann Intern Med. 2009;150(9):604-612.
- KDIGO 2012 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease.
Frequently Asked Questions
What does eGFR measure?
eGFR (estimated Glomerular Filtration Rate) estimates how well your kidneys filter waste from the blood. It is expressed in mL/min/1.73 m² and is the primary marker for staging chronic kidney disease (CKD).
What is the difference between CKD-EPI and MDRD equations?
The 2021 CKD-EPI equation is more accurate at higher GFR levels (above 60 mL/min/1.73 m²) and no longer uses a race coefficient. MDRD tends to underestimate GFR in healthier patients. CKD-EPI is now the recommended standard.
What eGFR level indicates kidney disease?
An eGFR below 60 mL/min/1.73 m² sustained for 3 or more months indicates CKD. Stages range from G1 (≥90, normal) to G5 (<15, kidney failure). Values between 60–89 may be normal in older adults if no other markers of kidney damage are present.
Can eGFR be affected by diet or medications?
Yes. High protein intake, creatine supplements, and certain medications (e.g., trimethoprim, cimetidine) can raise serum creatinine and falsely lower eGFR without reflecting true kidney function changes.
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⚠ Medical Disclaimer
This tool is for educational and informational purposes only. It is not intended to replace professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare professional for clinical decisions.