eGFR Calculator
Estimate Glomerular Filtration Rate using serum creatinine, age, and sex based on the standardized 2021 CKD-EPI clinical equation.
About Glomerular Filtration Rate (eGFR)
Estimated Glomerular Filtration Rate (eGFR) evaluates kidney filtration function. It measures how many milliliters of blood the glomeruli filter per minute adjusted for body surface area.
The CKD-EPI 2021 Clinical Standard
The 2021 CKD-EPI update eliminated race-based coefficients to enhance equity and clinical standardization in diagnosing Chronic Kidney Disease (CKD).
Staging Guidelines
- Stage 1 (Normal / High): eGFR ≥ 90 mL/min/1.73m²
- Stage 2 (Mild Reduction): eGFR 60 - 89 mL/min/1.73m²
- Stage 3a/3b (Moderate Reduction): eGFR 30 - 59 mL/min/1.73m²
- Stage 4 (Severe Reduction): eGFR 15 - 29 mL/min/1.73m²
- Stage 5 (Kidney Failure): eGFR < 15 mL/min/1.73m²
Frequently Asked Questions
Can intense exercise alter serum creatinine?
Yes. Intense weight lifting or creatine supplementation increases serum creatinine, which can artificially lower eGFR readings.
Why does eGFR decline with age?
Renal nephron density naturally declines with age, producing an average drop of ~1 mL/min/1.73m² per year after age 40.
Does a single low reading diagnose CKD?
No. Chronic Kidney Disease requires abnormal markers to persist for at least 3 continuous months.
When is Cystatin-C testing ordered?
Cystatin-C is requested when serum creatinine might be skewed by exceptional muscle mass, amputation, or liver dysfunction.
Calculate in three steps
- 1Enter your valuesUse the fields above and check the units shown beside each input.
- 2Run the calculationSelect Calculate to refresh the result with your latest values.
- 3Review or shareCompare the result, reset the form, print it, or share this page.