GFR Category Calculator
Classify an eGFR value into its KDIGO chronic-kidney-disease stage (G1–G5) and see what that category means for kidney function.
How it works
Category by eGFR (mL/min/1.73m²): G1 ≥90 · G2 60–89 · G3a 45–59 · G3b 30–44 · G4 15–29 · G5 <15
The KDIGO guideline sorts estimated glomerular filtration rate into six categories from G1 (normal) to G5 (kidney failure). This tool takes an eGFR you already have — from a blood test that estimates it from creatinine — and tells you which category it falls in and what that broadly means. It does not calculate eGFR itself and does not diagnose chronic kidney disease: G1 and G2 are only abnormal when combined with other evidence of kidney damage, and diagnosis requires the change to persist for at least three months.
Worked example
An eGFR of 52 mL/min/1.73m² is between 45 and 59, so it falls in category G3a — mild to moderately decreased function. If it stays there for three months it would meet the definition of stage 3a chronic kidney disease.
Sources: KDIGO 2012 CKD classification
Frequently asked questions
Does a low eGFR mean I have kidney disease?
Not by itself. Chronic kidney disease requires reduced eGFR (below 60) or markers of kidney damage such as albuminuria that persist for at least three months. A single low reading can reflect dehydration, medication or lab variation, so results are repeated and interpreted by a clinician.
Why is G1 “normal or high” still a category?
The staging system covers everyone, so a normal filtration rate is category G1. It is only meaningful as a disease stage when paired with a damage marker — otherwise G1 simply describes healthy kidney function.
How is eGFR estimated?
Laboratories calculate it from your blood creatinine along with age and sex using an equation such as CKD-EPI. To estimate the value itself, use a dedicated eGFR or creatinine-clearance calculator; this tool only classifies a value you already have.
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Educational estimate only — not medical advice, and not a substitute for a clinician, pharmacist or product label. Dosing, fluid and kidney decisions must be confirmed by a qualified professional using the actual drug, patient and situation. Do not use this tool to self-treat.