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GFR Calculator — eGFR Kidney Function

Calculate estimated glomerular filtration rate (eGFR) using the CKD-EPI 2021 equation and assess kidney function.

Calculated using CKD-EPI 2021 (race-free, KDIGO-recommended). Not a substitute for medical diagnosis.

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CKD Stages (KDIGO)

G1Normal or high
≥ 90
G2Mildly decreased
60 – 89
G3aMildly to moderately decreased
45 – 59
G3bModerately to severely decreased
30 – 44
G4Severely decreased
15 – 29
G5Kidney failure
< 15

About This Calculator

CKD-EPI 2021 Equation

The CKD-EPI 2021 equation is the current KDIGO (Kidney Disease: Improving Global Outcomes) recommended formula. It is race-free and provides accurate estimates across all age and creatinine ranges.

Medication Dosing

Many medications are dosed based on eGFR or are contraindicated with reduced kidney function, including metformin, NSAIDs, certain antibiotics, and contrast agents.

Limitations

eGFR equations estimate kidney function — they do not directly measure it. Results may be less accurate in extreme muscle mass, malnutrition, acute kidney injury, or pregnancy.

Medical Disclaimer

This tool is for informational purposes only and does not replace medical evaluation. Abnormal kidney values should always be discussed with a healthcare provider.

Read more

GFR Calculator — Understanding eGFR & Kidney Function →

Calculate eGFR using CKD-EPI 2021 and understand your kidney function. What do GFR values mean, CKD stages G1–G5, and when to see a doctor.