ROUNDS·
Renal · CKD-EPI 2021

CKD-EPI Calculator (eGFR)

Estimates glomerular filtration rate using the 2021 race-free CKD-EPI creatinine equation — the current standard for staging chronic kidney disease.

What is CKD-EPI?

CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) is the creatinine-based equation currently recommended for estimating glomerular filtration rate (eGFR) in adults. It's generally more accurate than the older Cockcroft-Gault formula, particularly at higher GFR values, and is the basis for chronic kidney disease (CKD) staging worldwide.

How to calculate eGFR with CKD-EPI

The equation uses age, sex, and serum creatinine. In 2021, the National Kidney Foundation and American Society of Nephrology jointly recommended removing the race coefficient that earlier versions of CKD-EPI had included — a change adopted because using race as a biological variable in this context lacked sufficient physiological justification and risked contributing to inequitable care. This calculator uses the current 2021 race-free equation.

Interpretation — CKD staging (KDIGO)

StageeGFR (mL/min/1.73m²)Description
G1≥90Normal or high
G260–89Mildly decreased
G3a45–59Moderately decreased
G3b30–44Moderately–severely decreased
G415–29Severely decreased
G5<15Kidney failure

A formal CKD diagnosis also requires these findings to persist for at least 3 months, and staging is refined further by combining eGFR with albuminuria category (A1/A2/A3) per KDIGO guidelines.

CKD-EPI vs. Cockcroft-Gault

Cockcroft-Gault estimates creatinine clearance rather than true GFR, and was developed decades earlier on a smaller, less representative population. It's still used for some drug-dosing decisions (it's embedded in many drug labels), but CKD-EPI is preferred for CKD staging and diagnosis. ROUNDS includes both — see the Creatinine Clearance calculator for the Cockcroft-Gault version.

References

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. KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of CKD.

See also: AKI Approach — pre-renal, intrinsic, and post-renal causes.

Frequently Asked Questions

Why was race removed from the CKD-EPI equation?

The 2021 race-free refit was adopted because the previous race coefficient lacked sufficient physiological justification and risked contributing to inequitable care.

Is CKD-EPI better than Cockcroft-Gault?

For staging and diagnosing CKD, yes — it's more accurate, especially at higher GFR. Cockcroft-Gault is still used for some drug-dosing decisions since many drug labels reference it directly.