Glomerular Filtration Rate (eGFR) Calculator
Estimate kidney filtration rate and Chronic Kidney Disease (CKD) staging using the latest peer-reviewed clinical guidelines.
Clinical Educational Disclaimer: This calculator is for screening and physiological informational purposes only based on the 2021 CKD-EPI equation. It is not a substitute for clinical medical diagnosis. Please consult a qualified nephrologist or primary care physician to interpret lab results.
Your estimated filtration rate indicates normal or optimal kidney function.
KDIGO 2012 Chronic Kidney Disease (CKD) Stages
Clinical interpretation guidelines endorsed by the National Kidney Foundation:
| Stage | eGFR (mL/min/1.73m²) | Clinical Description | Recommended Action |
|---|---|---|---|
| Stage G1 | ≥ 90 | Normal or high filtration | Routine wellness monitoring |
| Stage G2 | 60 – 89 | Mildly decreased filtration | Monitor blood pressure, glucose & hydration |
| Stage G3a | 45 – 59 | Mild to moderately decreased | Physician consultation, urinary albumin test |
| Stage G3b | 30 – 44 | Moderately to severely decreased | Nephrology evaluation, medication adjustments |
| Stage G4 | 15 – 29 | Severely decreased filtration | Active nephrologist care & preparation |
| Stage G5 | < 15 | Kidney failure (End-stage renal disease) | Renal replacement therapy (dialysis/transplant) |
GFR Frequently Asked Questions
What is Glomerular Filtration Rate (eGFR)?
Glomerular Filtration Rate (eGFR) is a clinical estimate of the volume of blood filtered by the microscopic glomeruli in the kidneys per minute, normalized to a standard body surface area of 1.73 m² (mL/min/1.73 m²). It is the gold standard indicator of kidney health and filtration efficiency.
What is the 2021 CKD-EPI equation and why is it significant?
Published in The New England Journal of Medicine in November 2021 (Inker et al.), the 2021 CKD-EPI Creatinine equation is the official race-free guideline adopted by the National Kidney Foundation (NKF) and American Society of Nephrology (ASN). It provides superior diagnostic precision across diverse clinical populations without racial correction factors.
What does an eGFR above 90 mean?
An eGFR of 90 mL/min/1.73 m² or higher indicates normal or optimal kidney function (KDIGO Stage G1), provided there are no other clinical markers of kidney damage such as persistent proteinuria (albumin in urine) or structural anomalies.
Can intense exercise or high muscle mass elevate serum creatinine?
Yes. Creatinine is a natural byproduct of creatine phosphate breakdown in skeletal muscle. Individuals with exceptional muscular mass or those performing intense resistance exercise may have slightly higher serum creatinine, leading to an artificially lower eGFR calculation.
Scientific References & Peer-Reviewed Literature
- Inker LA, Eneanya ND, Coresh J, et al. (2021). New Creatinine- and Cystatin C–Based Equations to Estimate GFR without Race. The New England Journal of Medicine, 385(19), 1737–1749. DOI: 10.1056/NEJMoa2102953. PMID: 34554658.
- Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. (2013). KDIGO 2012 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney International Supplements, 3(1), 1–150.
- Levey AS, Bosch JP, Lewis JB, et al. (1999). A more accurate method to estimate glomerular filtration rate from serum creatinine: a new prediction equation (MDRD). Annals of Internal Medicine, 130(6), 461–470. PMID: 10075613.
