GFR Calculator · Practical guide
What Is a Normal GFR for My Age?
A GFR of 90 or above is normal at any age, but eGFR naturally declines as you get older.
At a glance
The Short Answer
A normal eGFR is 90 mL/min/1.73m² or higher, regardless of age. However, kidney filtration declines naturally with age — roughly 1 mL/min per year after age 30 — so an eGFR in the 60s or 70s can be typical for a healthy older adult. Enter your age, gender, and creatinine above to see your own estimate.
Interactive tool
GFR Calculator
Enter your own values, then compare the result with the examples below.
Results
eGFR by Age: Worked Numbers
Using the CKD-EPI 2021 equation with a serum creatinine of 1.0 mg/dL, the calculator produces these estimates:
| Age | Female eGFR | Male eGFR |
|---|---|---|
| 30 | 75.8 | 100.5 |
| 40 | 70.6 | 93.7 |
| 50 | 65.8 | 87.4 |
| 60 | 61.4 | 81.4 |
| 70 | 57.2 | 75.9 |
Notice how the same creatinine level yields a lower eGFR at older ages — that is the age term in the equation at work.
Why Age Changes the Interpretation
An eGFR of 60-89 is labeled stage G2, or mildly decreased. In a 75-year-old with no other signs of kidney damage, that is often considered normal aging. In a 25-year-old, the same number would prompt further testing. Doctors look at eGFR together with urine albumin, blood pressure, and trends over time.
When to Be Concerned
An eGFR below 60 for three months or more meets the definition of chronic kidney disease, whatever your age. Below 30 is severe. A single low reading is not a diagnosis — hydration, muscle mass, and medications can shift creatinine — so always review results with a healthcare provider.
Frequently Asked Questions
Is an eGFR of 60 normal for a 70-year-old?
It is common. Kidney function declines gradually with age, so many healthy 70-year-olds have an eGFR in the 60s. Whether it needs follow-up depends on other findings like urine protein.
Why does the calculator need my age?
Both the CKD-EPI and MDRD equations include an age term because kidney filtration naturally declines with age. The same creatinine means different eGFR values at different ages.
Does muscle mass affect eGFR?
Yes. Creatinine comes from muscle, so very muscular people can show a lower eGFR than their true kidney function, and frail elderly people can show a misleadingly high one.
Can eGFR improve?
If a low reading came from dehydration or a temporary illness, eGFR can rebound. Age-related and chronic declines usually do not reverse, but treatment can slow further loss.