eGFR Calculator
Calculate your estimated glomerular filtration rate (eGFR) using the 2021 CKD-EPI creatinine equation.
This calculator provides an estimate of GFR and is not a substitute for professional medical evaluation.
using the 2021 CKD-EPI equation. Enter your age, sex, and
serum creatinine level to calculate your estimated glomerular filtration
rate (eGFR). If you also have a standardized cystatin C result, you can
use the combined creatinine-cystatin C equation for a potentially more
accurate estimate.
should not be interpreted as a diagnosis by itself. Your result should
be evaluated together with your medical history, urine tests, previous
kidney function results, and other clinical findings.
What Is eGFR?
eGFR stands for estimated glomerular filtration rate.
It is a calculated estimate of how efficiently the kidneys filter waste
and excess fluid from the blood.
The result is usually reported in
mL/min/1.73 m².
The value is estimated from laboratory measurements and patient
characteristics rather than being directly measured.
Serum creatinine is commonly used to estimate GFR because it is widely
available. However, creatinine levels can be affected by factors such as
muscle mass and other individual characteristics. For this reason,
cystatin C can sometimes provide additional information about kidney
filtration.
How Is eGFR Calculated?
For adults aged 18 years and older, the current CKD-EPI equations include
the 2021 CKD-EPI creatinine equation and the
2021 CKD-EPI creatinine-cystatin C equation.
These equations do not include a race coefficient.
The creatinine-based equation uses:
- Age
- Sex
- Standardized serum creatinine
The combined equation uses:
- Age
- Sex
- Standardized serum creatinine
- Standardized serum cystatin C
The 2021 CKD-EPI creatinine equation is recommended for estimating GFR in
adults, while the combined creatinine-cystatin C equation can provide a
more accurate estimate in appropriate clinical situations.
eGFR Categories
eGFR values are commonly divided into the following categories:
| eGFR | GFR Category | General Interpretation |
|---|---|---|
| ≥90 | G1 | Normal or high |
| 60–89 | G2 | Mildly decreased |
| 45–59 | G3a | Mildly to moderately decreased |
| 30–44 | G3b | Moderately to severely decreased |
| 15–29 | G4 | Severely decreased |
| <15 | G5 | Kidney failure range |
that a person has chronic kidney disease. CKD classification depends on
the overall clinical picture and evidence of kidney damage or persistently
reduced kidney function.
What Does a Low eGFR Mean?
A low eGFR generally indicates that the kidneys are filtering blood less
efficiently. However, the meaning of a low result depends on the patient's
age, medical history, previous eGFR values, urine findings, and other
laboratory results.
A single abnormal eGFR result should not automatically be interpreted as
chronic kidney disease. Kidney function is often assessed by looking at
results over time and by considering other markers of kidney damage.
Urine albumin or protein measurements can provide important additional
information about kidney disease and kidney disease risk.
What Does an eGFR of 60 Mean?
An eGFR around 60 mL/min/1.73 m² indicates a reduction in estimated kidney
filtration compared with higher GFR levels.
However, an eGFR of 60 by itself does not establish a diagnosis of chronic
kidney disease. The result needs to be interpreted in combination with
urine albumin, other kidney findings, medical history, and whether the
reduction persists.
What Does an eGFR of 30 Mean?
An eGFR of approximately 30 mL/min/1.73 m² represents significantly reduced
kidney filtration and falls at the boundary between G3b and G4 depending
on the exact value.
People with substantially reduced kidney function generally require
appropriate medical follow-up and assessment of the cause and progression
of kidney disease.
What Does an eGFR of 15 Mean?
An eGFR below 15 mL/min/1.73 m² is within the
G5 kidney failure range.
This is a serious reduction in kidney function and generally requires
specialist nephrology care.
However, the eGFR number alone does not determine exactly when dialysis
should begin. Symptoms, biochemical abnormalities, fluid status,
nutritional status, complications of kidney failure, and the overall
clinical condition are also considered.
Does a Low eGFR Mean I Need a Kidney Transplant?
Not necessarily.
eGFR is an important measure of kidney function, but it is only one part
of a kidney transplant assessment.
Kidney transplantation is considered based on the patient's overall
medical condition and suitability for transplantation, not simply on one
eGFR value.
A transplant evaluation may include assessment of:
- Kidney function and its trend over time
- The underlying cause of kidney disease
- Urine protein or albumin levels
- Cardiovascular health
- Infections and infection risk
- Other significant medical conditions
- Blood group
- HLA typing and immunological testing when appropriate
- Potential living donor suitability
- General surgical and anesthetic risk
For patients with advanced chronic kidney disease, discussing kidney
replacement therapy options early can allow sufficient time for
appropriate evaluation and preparation.
Learn more about:
Kidney Transplant
and
Kidney Transplant Evaluation
.
Does an eGFR Below 15 Automatically Mean Dialysis?
No. An eGFR below 15 is within the kidney failure range, but the decision
to start dialysis is individualized.
Nephrologists consider the patient's symptoms, complications of kidney
failure, fluid balance, electrolyte and acid-base abnormalities,
nutritional status, and other clinical factors rather than relying on
the eGFR number alone.
Kidney transplantation and dialysis are different forms of kidney
replacement therapy. For an appropriate patient, transplantation may be
considered before or after dialysis depending on the clinical situation
and transplant evaluation.
How Accurate Is an eGFR Calculator?
eGFR is an estimate, not a direct measurement of GFR.
Therefore, the calculated value should not be interpreted as an exact
measurement of kidney filtration.
The accuracy of creatinine-based eGFR can be affected when serum creatinine
does not accurately reflect kidney filtration. Factors such as unusually
high or low muscle mass and certain clinical conditions can influence
serum creatinine.
When creatinine may be an unreliable marker or when a result is close to
an important clinical decision threshold, cystatin C and the combined
creatinine-cystatin C equation may provide additional information.
When Should You See a Kidney Specialist?
Consider discussing your kidney function with a healthcare professional
if you have:
- Persistently reduced eGFR
- A significant decline in eGFR over time
- Persistent protein or albumin in the urine
- Known chronic kidney disease
- Repeatedly elevated serum creatinine
- A history of kidney disease
- Conditions that increase the risk of kidney disease
If your kidney function is significantly reduced or progressively
declining, a nephrologist can assess the cause, estimate the risk of
progression, and discuss appropriate kidney replacement therapy options
when necessary.
Considering Kidney Transplantation?
If you or a family member has advanced kidney disease and you are
considering kidney transplantation, our medical team can review your
available medical information and help determine the next steps for
transplant evaluation.
Frequently Asked Questions About eGFR
What is a normal eGFR?
An eGFR of 90 mL/min/1.73 m² or higher is categorized as G1, or normal/high.
However, eGFR alone does not determine whether kidney disease is present.
What does an eGFR of 60 mean?
An eGFR of 60 indicates reduced estimated kidney filtration. Whether this
represents chronic kidney disease depends on the overall clinical picture,
including urine findings and persistence over time.
What does an eGFR of 30 mean?
An eGFR of 30 represents significantly reduced kidney filtration and is
within the G3b range. Medical evaluation and follow-up are generally
appropriate.
What does an eGFR of 15 mean?
An eGFR below 15 is within the G5 kidney failure range. It requires
appropriate specialist evaluation, but the number alone does not determine
when dialysis or transplantation should begin.
Can creatinine be used to calculate eGFR?
Yes. The 2021 CKD-EPI creatinine equation estimates eGFR using age, sex,
and standardized serum creatinine.
Is cystatin C better than creatinine?
Creatinine and cystatin C are different filtration markers. In appropriate
patients, using both together can provide a more accurate eGFR estimate
than using creatinine alone.
Can I calculate eGFR if my creatinine is reported in µmol/L?
Yes. Creatinine reported in µmol/L can be converted to mg/dL by dividing
the value by 88.4. Our calculator can perform this conversion
automatically.
Does a low eGFR mean I need a kidney transplant?
No. eGFR is only one factor in kidney transplant evaluation. Transplant
suitability depends on the patient's overall health, kidney disease,
surgical risk, immunological assessment, donor considerations, and other
clinical factors.
Does an eGFR below 15 mean I need dialysis?
Not automatically. An eGFR below 15 is in the kidney failure range, but
dialysis decisions are individualized and depend on symptoms,
complications, laboratory abnormalities, fluid status, and other clinical
factors.
Is this calculator suitable for children?
No. This calculator is intended for adults aged 18 years and older.
Children and adolescents may require age-appropriate pediatric equations.
Medical Disclaimer
This eGFR calculator is provided for educational and informational
purposes only. It does not replace professional medical advice,
diagnosis, or treatment.
The calculated eGFR is an estimate and should be interpreted by a qualified
healthcare professional in the context of the patient's clinical history,
laboratory results, urine findings, and other relevant information.
Do not start, stop, or change medical treatment based solely on the result
of this calculator.
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