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Health Risk

eGFR Calculator (Kidney Function)

Estimate your glomerular filtration rate (eGFR) using the 2021 CKD-EPI creatinine equation, the current standard for staging chronic kidney disease and adjusting drug doses.

Enter lab values

Your kidney function estimate

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eGFR (mL/min/1.73m²)
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CKD stage
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Function
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Dose adjust

Why eGFR replaced creatinine alone

Serum creatinine alone is a poor measure of kidney function because it depends heavily on muscle mass, age, sex, and diet. A creatinine of 1.2 mg/dL may be normal for a muscular young man but indicate significant kidney disease in a frail 80-year-old woman. The estimated Glomerular Filtration Rate (eGFR) uses creatinine together with age, sex, and (historically) race to produce a single number, milliliters per minute per 1.73 m² of body surface, that reflects how well the kidneys are filtering.

The 2021 race-free update

For decades, the CKD-EPI equation included a multiplier of 1.16 for Black patients, based on observational data suggesting Black adults had higher average creatinine for any given GFR. In 2021, the National Kidney Foundation and ASN recommended removing the race multiplier after evidence that it could delay care for Black patients by overstating their kidney function. The new 2021 CKD-EPI creatinine equation, used in this calculator, is race-free and is now the standard in most U.S. labs.

CKD stages and what they mean

CKD is classified into five stages. G1 (eGFR ≥90) and G2 (60-89) are considered normal or mildly reduced, but kidney damage markers (proteinuria, imaging abnormalities) must be present to diagnose CKD at these stages. G3a (45-59) and G3b (30-44) represent moderate disease, most patients are asymptomatic but medication doses need adjustment. G4 (15-29) is severe; nephrology referral is mandatory. G5 (<15) is kidney failure, typically requiring dialysis or transplant.

What protects kidney function

The three biggest threats to kidney function are diabetes, hypertension, and NSAID overuse. Tight glucose control (A1C under 7-8%) slows diabetic nephropathy dramatically. BP under 130/80, particularly with an ACE inhibitor or ARB, protects the glomerulus. Avoiding daily ibuprofen, naproxen, or related NSAIDs prevents hemodynamic kidney injury. Staying well hydrated, avoiding high-dose vitamin C and excessive protein supplements, and treating urinary obstruction early all help preserve function over decades.

Editorial and formula review
Formulas verified against published peer-reviewed sources Last verified

Formula sources, population limits, and references for this health risk calculator are documented in our public methodology. Read the methodology · Medical disclaimer

Frequently asked questions

An eGFR of 90 or higher is normal. 60-89 is mildly reduced but usually fine. Below 60 for more than 3 months indicates chronic kidney disease.
Yes. eGFR naturally falls about 1 mL/min per year after age 40. An eGFR of 60 in an 80-year-old is less concerning than the same value in a 30-year-old.
If eGFR is below 60, daily NSAIDs (ibuprofen, naproxen) should generally be avoided. Occasional use is usually fine, but discuss with your clinician, especially if you also take BP medications.
High muscle mass raises creatinine, which lowers eGFR even if true kidney function is normal. A 24-hour urine creatinine clearance or cystatin C-based eGFR gives a more accurate estimate in muscular individuals.
Acute kidney injury often recovers. Chronic kidney disease (CKD) is usually progressive, but slowing progression, via BP and glucose control, ACE/ARB therapy, and avoiding nephrotoxins, is achievable.