GFR Calculator - Estimate Kidney Function in Real Time

Calculate Your GFR

Age (Years)

years

Gender

Male Female

Serum Creatinine

mg/dL

Race/Ethnicity

Race factor used in CKD-EPI formula

Additional Parameters (Optional)

Enable Height & Weight

Formula

CKD-EPI is more accurate at higher GFR levels

GFR Results & Kidney Health Status

Estimated Glomerular Filtration Rate

mL/min/1.73m² Enter values

Chronic Kidney Disease (CKD) Stages

Stage	GFR Range	Status
1	≥ 90	Normal or high
2	60-89	Mild reduction
3a	45-59	Mild to moderate
3b	30-44	Moderate to severe
4	15-29	Severe reduction
5	< 15	Kidney failure

Interpretation & Recommendations

Enter your values above to see personalized interpretation and recommendations for your kidney health.

Kidney Health Information

What is GFR?

Glomerular Filtration Rate measures how well your kidneys filter blood. It's the best overall indicator of kidney function.

Healthy Lifestyle Tips

Maintain healthy blood pressure, control blood sugar, stay hydrated, and avoid NSAIDs to protect kidney function.

When to See a Doctor

Consult a healthcare provider if your GFR is below 60 mL/min/1.73m² or if you have symptoms like swelling or fatigue.

GFR History & Trends

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Understanding Your GFR Results and Kidney Health

The Glomerular Filtration Rate (GFR) calculator is an essential tool for assessing kidney function. Your GFR value indicates how well your kidneys are filtering waste from your blood, which is critical for overall health maintenance.

How to Use This GFR Calculator

This kidney function calculator requires just three key pieces of information: your age, gender, and serum creatinine level. The calculator uses the CKD-EPI formula (considered the most accurate) or the MDRD formula to estimate your GFR in real-time.

Interpreting Your Results

GFR results fall into six stages of Chronic Kidney Disease (CKD):

Stage 1 (GFR ≥ 90): Normal or high kidney function with some signs of kidney damage
Stage 2 (GFR 60-89): Mild reduction in kidney function
Stage 3a (GFR 45-59): Mild to moderate reduction
Stage 3b (GFR 30-44): Moderate to severe reduction
Stage 4 (GFR 15-29): Severe reduction in kidney function
Stage 5 (GFR < 15): Kidney failure, requiring dialysis or transplant

Factors That Affect GFR

Several factors can influence your glomerular filtration rate calculation:

Age: GFR naturally decreases with age (about 1 mL/min/1.73m² per year after age 40)
Muscle Mass: Creatinine levels are affected by muscle mass, which is why the formula accounts for gender
Race: The CKD-EPI formula includes a race adjustment factor
Body Size: GFR is normalized to body surface area (1.73m²)

Limitations of GFR Estimation

While this renal health calculator provides a valuable estimate, it has limitations:

Not accurate for extremes of age or body size
May be less reliable in pregnant women
Doesn't account for amputations or muscle-wasting conditions
Estimated GFR should be confirmed with measured GFR when clinical decisions are needed

When to Consult a Healthcare Provider

Use this kidney health assessment tool as a screening instrument, not a diagnostic tool. Always consult with a healthcare professional if:

Your GFR is consistently below 60 mL/min/1.73m²
You notice a rapid decline in your GFR over time
You have symptoms like swelling, fatigue, or changes in urine output
You have risk factors like diabetes, hypertension, or family history of kidney disease

Pro Tip: For the most accurate results, use serum creatinine measurements from fasting blood tests performed in a clinical laboratory. Track your GFR over time to monitor kidney health trends.

Glomerular Filtration Rate (GFR) Calculator