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eGFR calculator (CKD-EPI 2021)

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Calculate estimated glomerular filtration rate (eGFR) using the CKD-EPI 2021 equation, the current standard for CKD staging reported by laboratories. Includes CKD stage, interpretation and clinical guidance. Many drug labels still specify the Cockcroft-Gault CrCl Calculator for dosing, though that is now shifting toward eGFR.

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eGFR and CKD staging: what the numbers mean

eGFR (estimated glomerular filtration rate) measures how well your kidneys filter waste from the blood, expressed in mL/min/1.73m². It's the standard measure laboratories use to report kidney function and stage chronic kidney disease (CKD). The NIDDK, part of the NIH, maintains its own eGFR calculators and, like this one, uses the race-free CKD-EPI equations.

CKD-EPI 2021: why race was removed

The original CKD-EPI 2009 equation included a race coefficient that increased eGFR estimates for Black patients, based on the assumption of higher average muscle mass. This led to systematically delayed CKD diagnosis and transplant referral in Black patients. The 2021 revision removed this race variable entirely, a change the National Kidney Foundation explains was driven by recognising that race is a social, not biological, construct. The 2021 equation is now recommended by NIDDK, KDIGO and most major nephrology bodies.

eGFR vs CrCl for drug dosing

eGFR is the standard for CKD staging and clinical monitoring. Drug dosing has traditionally used Cockcroft-Gault CrCl instead, because that's the formula most existing renal dosing guidelines were built on, and the two values can differ significantly, especially in elderly patients. That said, the National Kidney Foundation now recommends moving medication-related decisions toward race-agnostic, BSA-adjusted eGFR, and the FDA's 2024 guidance for industry favours eGFR over CrCl in new pharmacokinetic studies. Until individual drug labels catch up with that shift, check our Creatinine Clearance Calculator and Renal Dose Adjustment Calculator for the value your specific dosing reference still expects.

CKD staging

G1 (eGFR ≥90): normal or high. G2 (60-89): mildly decreased. G3a (45-59): mild-moderate decrease. G3b (30-44): moderate-severe decrease. G4 (15-29): severe decrease. G5 (below 15): kidney failure. CKD staging also incorporates albuminuria, an eGFR alone doesn't fully stage CKD without urine protein data. At the lower stages, several common drugs, metformin and NSAIDs among them, become outright contraindicated rather than simply needing a lower dose; run the specific medication through our Contraindication Checker once you know the stage.

Frequently asked questions

An eGFR of 90 or above (G1) indicates normal or high kidney function. 60-89 (G2) is mildly decreased but may be normal for older adults. Below 60 for more than 3 months indicates CKD. The threshold for dialysis consideration is generally below 15 (G5), though timing depends on symptoms and clinical context.
Renal dosing guidelines for most existing drugs were developed using Cockcroft-Gault CrCl values, not eGFR, and the two equations can give meaningfully different results in elderly, obese or very lean patients. That is changing: the National Kidney Foundation now recommends race-agnostic, BSA-adjusted eGFR for medication-related decisions, and the FDA's 2024 guidance for industry favours eGFR over CrCl in new pharmacokinetic studies. Until drug labels and your institution's protocols catch up, check which value your specific dosing reference specifies.
The 2021 equation removed the race coefficient that was present in the 2009 version. The 2009 equation added approximately 16% to eGFR estimates for Black patients, which led to delayed CKD diagnosis and transplant referral in this population. The 2021 race-free equation is now recommended by NIDDK, KDIGO and most international nephrology bodies.