Why did the equation change in 2021?

The 2009 version applied a race coefficient that raised estimates for Black patients, which delayed referral and transplant listing. The 2021 revision removed it and is the current standard.

Does one low reading mean kidney disease?

No. Chronic kidney disease requires findings persisting over at least three months alongside other markers. A single value, particularly during illness or dehydration, does not establish anything.

Health & Fitnessclinical

eGFR Calculator

Estimated glomerular filtration rate by the 2021 CKD-EPI equation, which dropped the race coefficient. The number is an estimate with a wide interval and a single reading names no diagnosis, so this page reports the band a result falls in rather than assigning a stage.

Also called: gfr calculator, kidney function calculator.

Estimated GFR

79.3

79.3 mL/min/1.73m2 by CKD-EPI 2021. The estimate falls between 60 and 89, mildly reduced. Those are reference bands and not a diagnosis: staging requires findings persisting over at least three months alongside other markers, and this page does not assign one. The interval around a CKD-EPI estimate is roughly plus or minus 30 percent, so 79 is consistent with anything from about 55 to 103. Enter a weight to see Cockcroft-Gault, which several drug dosing references still use in preference to eGFR.

Creatinine in mg/dL

1.1

Creatinine in micromol/L

97.2

Cockcroft-Gault creatinine clearance

Which reference band this falls in

between 60 and 89, mildly reduced

On the range

The estimate falls between 60 and 89, mildly reduced. Those are reference bands and not a diagnosis: staging requires findings persisting over at least three months alongside other markers, and this page does not assign one. The interval around a CKD-EPI estimate is roughly plus or minus 30 percent, so 79 is consistent with anything from about 55 to 103.

On trends

Enter a weight to see Cockcroft-Gault, which several drug dosing references still use in preference to eGFR.

On the equation

Creatinine comes from muscle, so the same kidney function reads differently in a muscular person and a frail one. The equation is also invalid while creatinine is still moving, which is the case in acute illness.

How this is calculated

For reference only. Verify against your clinical protocol before acting on this number.

Method and background

This is what the calculation gives for the numbers you entered. It is an estimate, not advice, and it knows nothing about your situation beyond those numbers. Rules for United States change on a published schedule; the effective date is shown on every rule-based tool.

How this is calculated

CKD-EPI estimates filtration from creatinine, age and sex, using different exponents above and below a creatinine threshold. The 2021 revision removed the race coefficient that the 2009 equation applied, which had raised estimates for Black patients and delayed referrals as a result. Creatinine itself is the weak link: it comes from muscle, so the same kidney function gives a higher creatinine and a lower estimate in a muscular person and the reverse in a frail one. Cockcroft-Gault is shown alongside where a weight is given, because many drug dosing references are still written against it and the two do not agree.

the 2021 CKD-EPI equation, which removed the race coefficient the earlier version carried, with a further factor of 1.012 for female patients

S_c: Serum creatinine, mg/dL
k: 0.7 female, 0.9 male
a: minus 0.241 female, minus 0.302 male

Worked examples

Each of these is asserted on every build. If a change to the engine ever moved one of these answers, the build would fail before the page could print it.

a 55 year old man at 1.1 mg/dL

Serum creatinine: 1.1
Creatinine unit: mg/dL
Age: 55
Sex: Male
Weight, for Cockcroft-Gault: 0 kg

Estimated GFR79.3

CKD-EPI 2021 with the male coefficients

Open this example

the same creatinine in micromol/L

Serum creatinine: 97.24
Creatinine unit: micromol/L
Age: 55
Sex: Male
Weight, for Cockcroft-Gault: 0 kg

Estimated GFR79.3

boundary: unit conversion at 88.4 must round-trip

Open this example

Method and limits

What it assumes

Stable kidney function, since the equation is invalid while creatinine is moving.

What it deliberately does not model

A single eGFR does not diagnose anything. Chronic kidney disease is defined over at least three months with other findings.
Creatinine reflects muscle mass, so the estimate is unreliable at the extremes of body composition, in pregnancy, and in acute illness.
The interval around a CKD-EPI estimate is roughly plus or minus 30 percent.

Formula version 1.0.0 · definition 1.0.0 · United States · Report a problem with this calculator

Frequently asked questions

Why did the equation change in 2021?: The 2009 version applied a race coefficient that raised estimates for Black patients, which delayed referral and transplant listing. The 2021 revision removed it and is the current standard.
Does one low reading mean kidney disease?: No. Chronic kidney disease requires findings persisting over at least three months alongside other markers. A single value, particularly during illness or dehydration, does not establish anything.