eGFR by Age: Averages, CKD Thresholds, and Reading Your Result

An age chart gives context for an estimated glomerular filtration rate (eGFR), but it cannot tell you whether your kidneys are healthy. The three questions to answer are: What is the trend? Is there albumin or another damage marker in the urine? Has an abnormality persisted for at least three months?

This guide separates population averages from diagnostic thresholds. Use the eGFR calculator to reproduce an estimate, and keep the laboratory report for clinical interpretation.

What the age averages actually show

The National Kidney Foundation age chart lists the following average estimates. All values are in mL/min/1.73 m².

These are averages, not normal-range boundaries, treatment targets, or age-specific CKD cutoffs. The source groups everyone aged 70 and older together; it does not give a separate 80+ average. Muscle mass, the estimating equation, laboratory variation, and the population studied all affect comparison. Do not subtract a fixed amount for each birthday or aim to raise your result to the table average.

CKD categories do not change with age

KDIGO 2024 defines CKD using persistent abnormalities of kidney structure or function. An eGFR below 60 for at least three months meets a CKD criterion at any adult age. G1 and G2 need another persistent marker of kidney damage to establish CKD.

At a boundary, 60 belongs to G2, 45 to G3a, 30 to G3b, and 15 to G4. Laboratories round values, so a category change by one point need not represent a meaningful biological change. The CKD category tool explains these thresholds without diagnosing CKD.

Two examples that an age chart cannot resolve

An 80-year-old with eGFR 55: one result cannot establish chronicity. If values remain below 60 for at least three months, the result meets a CKD criterion even if urine albumin is low. Age influences prognosis, follow-up, and treatment goals; it does not exclude the diagnosis.

A 35-year-old with eGFR 95 and persistent albuminuria: the G1 filtration estimate does not rule out CKD. Urine albumin and its duration may establish kidney damage despite the apparently reassuring blood result.

Read your report in a useful order

1. Record the date, creatinine unit, laboratory eGFR, and equation if shown. A formula change can change the estimate without a change in creatinine.
2. Compare with prior results, including recent illness and medication changes. A sudden fall needs assessment sooner than routine chronic-disease follow-up.
3. Ask whether urine albumin-to-creatinine ratio (UACR) or other urine testing is needed. Blood and urine tests provide different information.
4. Discuss the timing of repeat tests. Do not wait three months to seek advice for a new low result; three months describes chronicity, not a mandatory delay in care.
5. Use the age average as context after these checks. Do not change fluids, supplements, or medicines to improve a comparison score.

Creatinine estimates can be less reliable with unusual muscle mass, pregnancy, or rapidly changing kidney function. A clinician may request cystatin C or another assessment. Read how the formula works and what to do after a sudden drop for these separate questions.