eGFR Calculator
Estimate your kidney function from creatinine and, if you have the value, Cystatin C. The calculator uses the CKD-EPI equations, which are also used by laboratories.
Note: This value does not indicate the presence or absence of a medical condition. Laboratory results can only be interpreted by a doctor in the overall clinical context.
eGFR explained simply
The eGFR (estimated glomerular filtration rate) indicates how much blood your kidneys filter per minute, based on an average body surface area of 1.73 m². It is not measured directly, but is estimated from laboratory values.
Creatinine and Cystatin C
Creatinine is produced during muscle metabolism and excreted by the kidneys. A lot of muscle mass, creatine as a dietary supplement, a meat-heavy meal, or hard training before the blood sample can increase the value; the eGFR then appears lower than the kidneys actually function. Cystatin C depends less on muscle mass. If both values are available, the combined estimate is the most accurate.
Formula
For creatinine and for creatinine with cystatin C, the calculator uses the 2021 CKD-EPI equations, for cystatin C alone the 2012 ones. They take age and gender into account and apply to adults aged 18 and over.
Classification
Medical guidelines (KDIGO) classify the eGFR into stages, given in ml/min/1.73 m²:
- G1: 90 and above
- G2: 60 to 89
- G3a: 45 to 59
- G3b: 30 to 44
- G4: 15 to 29
- G5: below 15
Chronic kidney disease is only diagnosed when a value below 60 persists for more than three months or other findings such as protein in the urine are present. A single value is not sufficient for this.
Do you have any questions?
The most important answers about eGFR and your result.
Why does my value differ from the laboratory report?
Why does my value differ from the laboratory report?
Some laboratories still use older formulas (CKD-EPI 2009 or MDRD) or only report values over 60 as “> 60.” Small differences are therefore normal.
What does the metabolic check measure?
What does the metabolic check measure?
11 values from a small blood sample that you take at home: blood lipids, liver, kidney (creatinine and eGFR), thyroid, inflammation, and vitamin B12. Blood sugar, HbA1c, insulin, and cystatin C are not included. You receive the results digitally and, upon request, discuss them via video with an independent doctor.
What do I do with my result?
What do I do with my result?
Discuss it with your doctor's office or via video call with an independent doctor. A single result is not a diagnosis; it is often checked again after some time, sometimes together with a urine test.