eGFR calculator (CKD-EPI 2021, race-free)

Estimates glomerular filtration rate (eGFR, mL/min/1.73 m²) from serum creatinine, age and sex with the 2021 CKD-EPI creatinine equation, which does not use race.

For healthcare professionals. Runs on your device. Nothing you enter is saved or sent.

eGFR (CKD-EPI 2021, race-free)

When this estimate is not valid

Unstable kidney function (acute kidney injury or a rapidly changing creatinine): creatinine-based estimates lag behind the true value.
Dialysis or other kidney replacement therapy: these equations do not apply.
Very high or very low muscle mass (cachexia, frailty, paraplegia, bodybuilding, malnutrition) or an unusual diet (high meat or creatine intake, vegetarian diet).
Limb amputation.
Pregnancy.
eGFR is indexed to 1.73 m². For drug dosing in very small or very large adults, the non-indexed value in mL/min may be more relevant; check the drug label.
Needs a standardised (IDMS-traceable) creatinine. Not for people under 18 years.

Estimate only. Interpret it with the patient's clinical picture and the product label.

How it is calculated

eGFR = 142 × min(SCr/κ, 1)^α × max(SCr/κ, 1)^−1.200 × 0.9938^age × 1.012 (women)

The 2021 CKD-EPI creatinine equation. κ is 0.7 for women and 0.9 for men; α is −0.241 for women and −0.302 for men; the result is multiplied by 1.012 for women. SCr is serum creatinine in mg/dL (µmol/L ÷ 88.4).

The result is rounded to a whole number, as on the National Kidney Foundation (NKF) calculator; the arithmetic shows one decimal.

eGFR (mL/min) = eGFR × BSA ÷ 1.73

With height and weight, the calculator also gives the value not indexed to body size, in mL/min, with the Mosteller body surface area. The National Kidney Foundation calculator uses the DuBois formula, so its non-indexed value can differ from this one by a few per cent.

The equation needs a standardised (IDMS-traceable) creatinine and is for adults aged 18 years and over. Limits: age 18–110 years, creatinine 0.2–20 mg/dL.

Worked example

A 50-year-old man with a serum creatinine of 1.0 mg/dL:

1 ÷ 0.9 = 1.111
142 × 1.0000 × 0.8812 × 0.7327 = 91.7 → 92 mL/min/1.73 m²

eGFR 92 mL/min/1.73 m².

Questions

Why does the 2021 equation not use race?

The 2009 CKD-EPI equation multiplied eGFR by 1.159 for people identified as Black. In 2021 Inker and colleagues published equations refitted without a race term (N Engl J Med 2021), and the National Kidney Foundation and the American Society of Nephrology recommend the race-free creatinine equation.

Should I use eGFR or CrCl for drug dosing?

Follow the product label. Many labels state renal dose adjustments as Cockcroft-Gault CrCl in mL/min; newer labels may use eGFR. eGFR in mL/min/1.73 m² is indexed to a standard body size; for very small or very large adults the non-indexed value in mL/min may be closer to what a label means. Both are estimates.

What does "indexed to 1.73 m²" mean?

The result is scaled to a body surface area of 1.73 m², an average adult size, so that kidney function can be compared between people. For the value of this person in mL/min, multiply by their body surface area and divide by 1.73; enter height and weight to see it.

Can I enter creatinine in µmol/L?

Yes. Choose µmol/L; the value is divided by 88.4 before the equation is applied, and the conversion is shown in the arithmetic.

When is eGFR not valid?

The equation is for adults with stable kidney function. It does not apply during dialysis, and it is unreliable with acute kidney injury, very high or low muscle mass, limb amputation, an unusual diet or pregnancy.

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;385(19):1737–1749. DOI 10.1056/NEJMoa2102953 PubMed 34554658
Mosteller RD. Simplified calculation of body-surface area. N Engl J Med. 1987;317(17):1098. DOI 10.1056/NEJM198710223171717 PubMed 3657876

Formula version: CKD-EPI 2021 creatinine (race-free) · MediHelp calc v1.0.1

Formula and sources checked on 2026-10-29