eGFR Calculator (CKD-EPI 2021)

Estimated GFR from creatinine, age and sex

Reviewed by the Nutricity editorial teamLast updated:
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Screening estimate only — not a diagnosis. Discuss any abnormal result with your doctor.

Quick answer

eGFR estimates how much blood the kidneys filter per minute, in mL/min/1.73 m². This tool uses the CKD-EPI 2021 race-free equation (creatinine, age, sex). A value ≥ 90 is considered normal; below 60 for more than 3 months suggests reduced kidney function to be assessed.

eGFRKDIGO stage
≥ 90G1 — normal
60–89G2 — mildly reduced
45–59G3a — mild-moderate
30–44G3b — moderate-severe
15–29G4 — severe
< 15G5 — kidney failure

How it is calculated

The CKD-EPI 2021 equation (Inker et al., NEJM 2021) estimates eGFR from serum creatinine, age and sex, dropping the race coefficient used in earlier versions. Creatinine can be entered in mg/dL or µmol/L (1 mg/dL = 88.4 µmol/L). The result is expressed for a standard body surface area of 1.73 m².

How to interpret the value

A single value is not enough: chronic kidney disease is defined by an abnormality persisting for more than 3 months, also considering albuminuria. eGFR should always be read together with other tests by a doctor. Cardiometabolic factors affect kidney health: see LDL cholesterol, metabolic syndrome and the HOMA-IR index.

Disclaimer

This is a screening tool for information only to help you interpret your lab value: it is not a diagnosis. Any abnormal value should be discussed with your doctor, who considers the trend over time, albuminuria and the clinical context.

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Frequently asked questions

What is eGFR?
It is the estimated glomerular filtration rate — how much blood the kidneys filter per minute, in mL/min/1.73 m². It is estimated from creatinine, age and sex with the CKD-EPI 2021 equation.
What is a normal eGFR?
An eGFR ≥ 90 mL/min/1.73 m² is considered normal. Values below 60 persisting for more than 3 months suggest possible chronic kidney disease to assess with a doctor.
Does the eGFR calculation replace a doctor?
No. It is an informational tool to interpret your report: it is not a diagnosis. An abnormal value should always be discussed with a doctor together with other tests.

Sources

  1. Inker LA, Eneanya ND, Coresh J, et al. New Creatinine- and Cystatin C-Based Equations to Estimate GFR without Race. N Engl J Med. 2021;385(19):1737-1749.
  2. KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease.
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