Biomarker guide
eGFR (mL/min/1.73m²)
eGFR (estimated glomerular filtration rate) estimates how many milliliters of blood your kidneys filter per minute, calculated from blood creatinine along with age and sex. It is the standard measure of kidney function, and people test it because kidney decline is typically silent until it is advanced.
Reference ranges
Commonly used adult reference ranges. Labs vary in methodology and cutoffs, interpret your results against your lab report's stated ranges and with your doctor.
For eGFR, lower is worse: 90+ is consistent with full kidney function, while sustained values below 60 are the commonly used threshold of concern.
| Zone | Range |
|---|---|
| Kidney failure range | 0–15 mL/min/1.73m² |
| Reduced | 15–60 mL/min/1.73m² |
| Mildly reduced | 60–90 mL/min/1.73m² |
| Optimal | 90–120 mL/min/1.73m² |
The importance of eGFR
The kidneys filter roughly 180 liters of blood a day, clearing waste and balancing fluids, electrolytes, and blood pressure. eGFR estimates that filtration capacity, and unlike most markers on this site, lower is worse: values above 90 are consistent with full function, while sustained values below 60 define chronic kidney disease staging.
Kidney function declines silently, most people feel nothing until the majority of function is gone, which is why eGFR appears on routine metabolic panels. A gradual drift downward across years matters more than any single reading, and the trend is especially worth watching for people with diabetes, high blood pressure, or a family history of kidney disease.
eGFR is an estimate with known blind spots: high muscle mass, creatine supplements, a large meat meal before the draw, and dehydration can each depress the calculated value without any true kidney change. An unexpectedly low result is usually repeated, sometimes with a cystatin C–based estimate or a urine albumin test, before conclusions are drawn, a follow-up path worth discussing with your doctor.
Frequently asked questions
What is a normal eGFR?
An eGFR of 90 mL/min/1.73m² or higher is consistent with normal kidney function in adults, and 60–89 is common with age and usually unremarkable without other findings. Sustained values below 60 for three months or more are the commonly used threshold for chronic kidney disease staging.
Can eGFR be low without kidney disease?
Yes. Because eGFR is calculated from creatinine, a muscle byproduct, high muscle mass, creatine supplementation, a meat-heavy meal before the draw, and dehydration can each lower the estimate without any true change in kidney function. A repeat test, sometimes using cystatin C instead, usually clarifies.
Does eGFR decline with age?
Gradually, yes, average eGFR falls roughly 1 mL/min per year after about age 40, so a value in the 60s–80s is common in older adults without disease. The rate of decline matters more than the absolute number, which is why year-over-year comparison is the most useful way to read it.
What helps protect kidney function?
The biggest levers are the ones that protect blood vessels: keeping blood pressure and blood sugar in range, not smoking, staying hydrated, and using NSAIDs (like ibuprofen) sparingly. People with diabetes or hypertension benefit most from regular eGFR and urine-albumin monitoring, on a schedule set with their doctor.
Panels that measure eGFR
Kidney Function Tests: eGFR, Creatinine & Urine Albumin Panels
Measure how well your kidneys filter, from a quick baseline panel to a deep blood-and-urine workup.
View panelGeneral Health Blood Test Panels: Full-Body Wellness Baseline
One blood draw, a complete snapshot of the core systems your health runs on.
View panelComprehensive Blood Test Panel: 17 Tests, 78 Biomarkers
One blood draw, 78 biomarkers, walk into your next appointment with real data.
View panel