eGFR Calculator

Category: Other Health
- May 14, 2025
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Calculate your Estimated Glomerular Filtration Rate (eGFR) to assess kidney function. This calculator uses the CKD-EPI equation which provides a more accurate estimate for people with higher eGFR levels.

Patient Information

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Understanding eGFR and Kidney Function

The estimated Glomerular Filtration Rate (eGFR) is a key indicator of kidney function. It estimates how much blood passes through the glomeruli (tiny filters in the kidneys) each minute, which helps assess kidney health and function.

Key Information About eGFR
  • Normal Range: Generally, an eGFR above 90 mL/min/1.73m² is considered normal (Stage 1)
  • Affected By: Age, gender, race, muscle mass, medications, and dietary factors
  • Calculation Methods: Different equations (CKD-EPI, MDRD, Cockcroft-Gault) may be used based on clinical settings
  • Clinical Use: Used to detect, evaluate, and monitor kidney disease progression
  • Limitations: An estimate only; can be less accurate in certain populations, including pregnant women, very elderly, amputees, or people with extreme body sizes
CKD Stages and Management
  • Stage 1 (≥90): Monitor, control risk factors (diabetes, hypertension), maintain healthy lifestyle
  • Stage 2 (60-89): Regular monitoring, manage underlying conditions, avoid kidney-toxic medications
  • Stage 3 (30-59): More frequent monitoring, possible referral to nephrologist, dietary adjustments
  • Stage 4 (15-29): Close monitoring by nephrologist, prepare for possible renal replacement therapy
  • Stage 5 (<15): Need for dialysis or kidney transplant often necessary
Improving Kidney Health
  • Blood Pressure Control: Maintain blood pressure within target ranges
  • Diabetes Management: Keep blood glucose levels well-controlled
  • Healthy Diet: Consider reducing sodium, phosphate, and protein if recommended
  • Medication Management: Avoid nephrotoxic drugs, adjust dosages of medications cleared by kidneys
  • Regular Exercise: Maintain appropriate physical activity
  • Avoid Dehydration: Maintain adequate fluid intake

Disclaimer: This calculator provides estimates based on standard equations and should not replace clinical judgment. Results should be interpreted by healthcare professionals in conjunction with clinical data and laboratory findings. Factors like muscle mass, diet, medications, and acute illness can affect serum creatinine and impact eGFR accuracy. Always consult with a healthcare provider for proper diagnosis and management of kidney conditions.

What Is the eGFR Calculator?

The eGFR Calculator is a kidney function tool that estimates your glomerular filtration rate (eGFR). This number reflects how efficiently your kidneys filter waste and excess fluid from your blood. It plays a key role in detecting early signs of chronic kidney disease (CKD) and tracking kidney Health over time.

This calculator is part of the ETG (Estimated Test Guide) platform, which focuses on providing fast, accessible clinical tools. Like a BAC estimation tool for alcohol levels or a Body Surface Area Calculator for dosing medications, this eGFR calculator supports informed health decisions without the need for complex medical software.

Formulas Used for eGFR Estimation

CKD-EPI (2009) Equation:
eGFR = 141 × min(Scr/κ, 1)^α × max(Scr/κ, 1)–1.209 × 0.993Age × Gender Factor × Race Factor

Where:
κ = 0.7 for females, 0.9 for males
α = –0.329 for females, –0.411 for males
Gender Factor = 1.018 for females, 1.0 for males
Race Factor = 1.159 if Black, 1.0 otherwise

How to Use the Calculator

This tool is simple and efficient. Follow these steps:

  • Enter your age (18 to 120 years).
  • Select your gender and race.
  • Input your serum creatinine value and unit (mg/dL or μmol/L).
  • (Optional) Add your height and weight for more accurate results using certain formulas.
  • Select the formula: CKD-EPI (default), MDRD, or Cockcroft-Gault.
  • Click “Calculate eGFR” to get results instantly.

What the Results Mean

Your eGFR result will be shown alongside its interpretation and CKD stage classification. Here’s a quick guide:

  • ≥ 90: Normal kidney function (Stage 1)
  • 60–89: Mildly reduced (Stage 2)
  • 45–59: Mild to moderate reduction (Stage 3a)
  • 30–44: Moderate to severe reduction (Stage 3b)
  • 15–29: Severe reduction (Stage 4)
  • < 15: Kidney failure (Stage 5)

The calculator also offers an explanation with health recommendations based on your result.

The Link Between ETG and eGFR

The ETG (Estimated Test Guide) framework brings together health calculators that estimate clinical values using standardized medical equations. Just like ETG tools such as the Body Type Calculator or Blood Pressure Calculator help users assess specific health markers, the eGFR calculator estimates kidney function quickly and clearly.

ETG calculators aim to improve awareness, promote prevention, and support self-monitoring. In the case of eGFR, early detection of kidney dysfunction allows for timely lifestyle changes or medical intervention—reducing the risk of progression to kidney failure.

Why Use This Tool?

  • Track your kidney function easily and without lab software.
  • Supports early detection of CKD when treatment is most effective.
  • Empowers discussions with your healthcare provider based on data.
  • Integrated with the ETG platform, ensuring reliable calculations.

FAQs

Is this calculator part of a medical diagnosis?

No. It’s an estimation tool. Only a licensed healthcare provider can diagnose kidney conditions using clinical data.

What if I don’t know my creatinine unit?

You can switch between mg/dL and μmol/L using the dropdown. If unsure, refer to your lab report or consult your doctor.

Do I need to include height and weight?

No, but including them improves accuracy for certain equations like Cockcroft-Gault.

How often should I check my eGFR?

It depends on your health history. People with conditions like Diabetes or hypertension may benefit from regular monitoring.

Conclusion

The eGFR Calculator within the ETG toolset helps you monitor kidney function with clarity and speed. Whether you're tracking a known condition or just staying informed, this tool supports better understanding of your renal health—and can prompt timely conversations with your healthcare provider.