Use this simple tool to estimate your glomerular filtration rate (GFR), a measure of kidney function. GFR reflects how well your kidneys are filtering blood and balancing hydration, electrolytes, and recovery — all of which are important for athletes as well as general health.
Why Use a GFR Calculator?
GFR provides insight into how efficiently your kidneys are working. For runners and endurance athletes, this means better understanding how your body handles fluid balance and metabolic waste during training. Tracking your GFR alongside other performance metrics helps build a clearer picture of your overall condition.
How It Works
The calculator estimates GFR using common formulas based on age, sex, weight, and serum creatinine. These values are combined to provide an approximate measure of kidney function. While this is not a replacement for laboratory testing, it offers a convenient way to check trends over time.
Typical Ranges
- Normal: 90 ml/min/1.73m² or above
- Mildly reduced: 60–89 ml/min/1.73m²
- Moderately reduced: 30–59 ml/min/1.73m²
- Severely reduced: below 30 ml/min/1.73m²
Values vary with age and body size. A single reading is less important than overall trends and should always be discussed with a healthcare professional if you’re concerned.
Important Note
This calculator is for educational purposes only. It should not be used to diagnose or treat medical conditions. If you have concerns about your kidney function or health, please consult a medical professional.
For more context on how GFR relates to running, hydration, and recovery, you can read our in-depth guide: Understanding GFR and Why It’s Useful for Training.
