GFR Calculator
Calculate your Glomerular Filtration Rate (GFR) using multiple validated formulas to assess kidney function. Get accurate results based on your age, gender, race, and serum creatinine levels.
Basic Information
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Laboratory Values
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Risk Factors
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What is Glomerular Filtration Rate (GFR)?
Glomerular filtration rate (GFR) measures how well your kidneys filter blood. It represents the rate of blood flow through tiny filters in your kidneys called glomeruli. A higher GFR generally indicates better kidney function, while a lower GFR may suggest kidney problems.
The normal range for GFR varies by age, gender, and body size. For most healthy adults under 40:
- Men: 100 to 130 mL/min/1.73m²
- Women: 90 to 120 mL/min/1.73m²
Population Mean Estimated GFR by Age
| Age Range | Mean GFR (mL/min/1.73 m²) |
|---|---|
| 20-29 | 116 |
| 30-39 | 107 |
| 40-49 | 99 |
| 50-59 | 93 |
| 60-69 | 85 |
| 70+ | 75 |
Understanding GFR Results and CKD Stages
| Stage | GFR Value (mL/min/1.73 m²) | Description |
|---|---|---|
| Normal | 90+ (no proteinuria) | Normal kidney function |
| CKD 1 | 90+ with kidney damage | Normal GFR with evidence of kidney damage |
| CKD 2 | 60-89 | Mild decrease in GFR with kidney damage |
| CKD 3 | 30-59 | Moderate decrease in GFR |
| CKD 4 | 15-29 | Severe decrease in GFR |
| CKD 5 | <15 | Kidney failure |
Factors Affecting GFR
- Age: GFR naturally decreases with age
- Gender: Men typically have higher GFR than women
- Race: Black individuals often have higher GFR than other races
- Body size: Larger body size generally correlates with higher GFR
- Medical conditions: Diabetes, hypertension, and other conditions can affect GFR
- Medications: Some medications can influence GFR measurements
- Diet: Protein intake and other dietary factors can affect creatinine levels
- Hydration status: Dehydration can temporarily lower GFR
Important Notes
- This calculator provides an estimate of your GFR using multiple formulas
- Results should be interpreted by a healthcare professional
- Regular monitoring is important for tracking kidney function over time
- Additional tests may be needed for a complete kidney function assessment
- Consult your healthcare provider for personalized medical advice