Calculate your estimated Glomerular Filtration Rate and kidney function.
eGFR is estimated from serum creatinine, age and the selected validated equation coefficients.The estimate uses the measurement, age and other fields requested by the selected equation. Laboratory methods, units, timing, medication, medical history and population-specific limitations can materially affect interpretation.
The Kidney Function (eGFR) Calculator provides an estimate of the most widely used estimate for kidney filtration: estimated glomerular filtration rate (eGFR). It provides estimates of kidney filtration using age, sex, and serum creatinine utilizing the 2021 CKD-EPI creatinine equation. This provides a result in units of mL/min/1.73 m. A computed estimate of kidney function based on an eGFR provides an approximation but is insufficient on its own to diagnose kidney disease or provide an assessment of one's overall health.
Enter all information as asked by the calculator as accurately as you can. The 2021 CKD-EPI creatinine equation uses three inputs.
The calculator then applies the equation and reports an estimated GFR normalized to a standard body surface area of 1.73 m².
This calculator estimated glomerular filtration rate from serum creatinine plus age and sex by using 2021 CKD-EPI creatinine equation that is a race-free equation used for estimating GFR in adults.
Creatinine is one of the waste products that can be tested using blood. However, as the Creatinine level depends upon parameters other than filtration and not directly to the filtration rate of the kidney, the calculation makes a combination of Creatinine and demographic data in order to give an estimated value.
The reported eGFR value has been normalized to a body surface area of 1.73 m. Standardized using a GFR to BSA ratio is helpful for comparing renal function; however, it will not directly reflect the patient's "actual" GFR.
The 2021 CKD-EPI creatinine equation is:
eGFR = 142 × min(Scr/κ, 1)α × max(Scr/κ, 1)−1.200 × 0.9938Age × 1.012 if female
Where:
There is no race coefficient in this equation. Since eGFR is an estimate it should be taken with regard to a persons clinical data and results from their laboratory.
Consider a 50-year-old male with a serum creatinine of 1.0 mg/dL.
Age: 50 years
Sex: Male
Serum creatinine: 1.0 mg/dL
For a male, κ = 0.9 and α = −0.302. Applying the 2021 CKD-EPI creatinine equation gives an eGFR of approximately 91.7 mL/min/1.73 m².
The above only demonstrates the calculation based on a few mathematical formulas. It is definitely not the assessment of kidney's health or a diagnosis.
EGFR is expressed as mL/min/1.73m; higher is better and lower is worse;
In chronic kidney disease evaluation eGFR is always used in conjunction with other information, including persistence of abnormalities and other measures of kidney damage. An eGFR does not by itself confirm the presence of chronic kidney disease.
| eGFR Result | General Interpretation |
|---|---|
| 90 or higher | Generally considered a normal or high eGFR range when interpreted in the appropriate clinical context |
| 60–89 | Mildly decreased range; may or may not indicate kidney disease depending on other findings and persistence |
| 45–59 | Moderately decreased range |
| 30–44 | Moderately to severely decreased range |
| 15–29 | Severely decreased range |
| Below 15 | Kidney failure range when the finding is persistent and clinically applicable |
These values alone, however, do not establish a diagnosis. Clinical interpretation in context is made in conjunction with factors such as endurance, urinalysis, prior eGFR values and clinical scenario.
The eGFR equation includes a measure of age, sex, and the amount of creatinine in the blood serum. Serum creatinine can be influenced by factors other than kidney filtration though.
The value of this calculator is for estimation, not the precise measurement of glomerular filtration rate. It is not for clinical use on its own to diagnose kidney disease or to find the cause of an abnormal kidney result or its treatment.
Creatinine-based equations are often not very representative in various clinical scenarios, such as those with atypical body muscle composition and volatile kidney function. It may sometimes be necessary to consider other clinical measurements to allow for a personalized approach to assessing kidney function.
The purpose of this calculator is for use in adults and should not be a replacement for a pediatric eGFR equation. It also does not take all of the issues a clinician might take into consideration when looking at kidney function into consideration.
For any anxiety relating to a abnormal eGFR or Creatinine result, Urine result or symptoms – always seek the help and reassurance of the appropriate health professional to discuss the result, do not adjust any medications or treatments based on a calculator result alone.
Here eGFR is explained with some detail:eGFR stands for estimated glomerular filtration rate, which is an estimate of kidney function. This calculation results in a value expressed in units of mL/min/1.73 m.
CKD-EPI creative equation for 2021 uses serum creatinine in mg/dl, therefore if the laboratory result value is provided in mol/l, please convert this measurement to mg/ dl before calculation.
An eGFR is only part of the picture and duration as well as other indicators of kidney damage need to be considered in determining chronic kidney disease.
Yes, as eGFR is derived from serum creatinine as well as other factors, and altering creatinine leads to altered eGFR estimations. Acute changes should be interpreted in the context of what the patient presents with.
EGFR is routinely normalized to a standard surface area of 1.73m². It serves as a normalisation factor making estimations of kidney function directly comparable against standard body size.
No. Race coefficient is not used in the 2021 CKD-EPI creatinine equation which is used by this calculator.
Use a recent value from a reliable measurement source and verify the unit before calculating. Discuss unexpected or abnormal results with a qualified clinician rather than changing treatment based on the calculator.
Creatinine levels in serum is associated with, but cannot replace measures of eGFR. Serum creatinine is a measure by laboratory of the levels of creatinine in blood. EGFR is an estimate derived from these creatinine levels plus a measure of age and sex using an equation established by a medical professional.
If the creatinine value represents an average that has the potential to yield various eGFR values, then looking only at the creatinine gives us different information from the eGFR.
An eGFR value can be an estimation of kidney filtration at a specific point in time. Where there are multiple results available the doctor is able to assess if the estimate of kidney filtration has altered over time rather than look at a single result.
An e GFR value of 72 mL/min/1.73 m would mean something different to the same patient if this was an isolated result or if a person's value previously was 50 mL/min/1.73 m and this current result is 72 mL/min/1.73 m, a significant improvement. Should be trended on raw lab result values and clinical context.
Differences in eGFR calculations arise from variation in the source creatinine value, in the input for age and sex, and from the difference in equation used. Laboratories and clinical systems may be using different validated equations for eGFR.
A normal eGFR is reported in terms of "per 1.73 m2 body surface area." Body surface area normalization is designed to level kidney filtration results for comparison, yet an indexed eGFR does not represent an individual's intrinsic GFR value.
Body size can therefore play a role when eGFR is being used in certain clinical context. It is the clinician's judgment whether a indexed or de-indexed value would be appropriate in a certain context.
| Measure | What It Represents |
|---|---|
| Serum creatinine | A blood concentration of creatinine |
| eGFR | An estimated filtration rate calculated from an equation |
| Measured GFR | A filtration rate determined using a direct measurement method rather than a creatinine-based estimation equation |
When used in standard assessment of various common conditions, eGFR is helpful to provide a comparative estimate in the absence of a direct measurement test. When a more accurate result is required by any physician the use of an alternative may be employed.
Creatinine-based eGFR calculation is not a perfect representation of kidney function in all situations. Problems in interpretation can arise when creatinine production or concentration is vastly different from the value assumed by the equation.
These limitations do not mean the calculation is useless; they mean the result may require additional clinical context.
TThe Kidney Function (eGFR) Calculator assesses kidney filtration, and does not measure all kidney function, nor does it measureurine protein oralbumin, determine what is causing a decrease in kidney function, or assess if a problem with the kidney is acute or chronic.
Nor does it directly make decisions about medication dosage. Which drug the decision is based on, which measure of renal function to use, whether the body size needs consideration or how the patients condition should guide the decision are all drug-specific and patient-specific decisions.
The units of eGFR are standard: mL/min/1.73 m. The "mL/min" is the standard measure of filtration rate. 1.73 m indicates the values have been adjusted for a "standard" body surface area.
EGFR units are not the same as serum creatinine units. Serum creatinine may be measured as mg/dL or mol/L. The resultant calculated eGFR is a filtrate rate.