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eGFR Calculator

eGFR Calculator

Calculate estimated Glomerular Filtration Rate (eGFR) to assess kidney function. Uses CKD-EPI and MDRD formulas with comprehensive kidney disease staging and recommendations.

Medical GradeMultiple FormulasCKD Staging
This calculator is for educational and informational purposes only. Not a substitute for medical advice. diagnosis, or treatment. Always consult with qualified healthcare providers for medical decisions and kidney function assessment.
Kidney Function Assessment
Enter patient information to calculate estimated glomerular filtration rate

Normal range: 0.6-1.3 mg/dL

Age in years (18-120)

Affects calculation multipliers in some formulas

Example eGFR Calculations
Sample kidney function assessments for different patient profiles
45 year old Male
Creatinine: 1.2 mg/dL
eGFR: ~75 mL/min/1.73m²
Stage 2
65 year old Female
Creatinine: 1.5 mg/dL
eGFR: ~40 mL/min/1.73m²
Stage 3
70 year old Male
Creatinine: 2.0 mg/dL
eGFR: ~35 mL/min/1.73m²
Stage 3
55 year old Female
Creatinine: 0.9 mg/dL
eGFR: ~70 mL/min/1.73m²
Stage 2
Understanding eGFR

Estimated Glomerular Filtration Rate (eGFR) measures how well your kidneys filter waste from your blood. It's the best overall indicator of kidney function.

Normal Values:

  • Normal: 90+ mL/min/1.73m²
  • Mild decrease: 60-89 mL/min/1.73m²
  • Moderate decrease: 30-59 mL/min/1.73m²
  • Severe decrease: 15-29 mL/min/1.73m²
  • Kidney failure: <15 mL/min/1.73m²

Formula Differences:

  • CKD-EPI: More accurate, especially at higher eGFR values
  • MDRD: Older formula, less accurate but still used
Clinical Applications

eGFR is used for:

  • Diagnosing chronic kidney disease (CKD)
  • Staging CKD severity
  • Monitoring kidney function over time
  • Adjusting medication dosages
  • Determining need for specialist referral
  • Planning for dialysis or transplant

Factors Affecting eGFR:

  • Age (decreases ~1 mL/min/1.73m² per year after 40)
  • Muscle mass (affects creatinine levels)
  • Diet (protein intake)
  • Medications
  • Acute illness or dehydration
When to See a Nephrologist

Stage 3 CKD

  • • eGFR 30-59 mL/min/1.73m²
  • • Moderate kidney function decline
  • • Need for CKD management
  • • Complication screening

Stage 4-5 CKD

  • • eGFR <30 mL/min/1.73m²
  • • Severe kidney dysfunction
  • • Prepare for dialysis/transplant
  • • Manage complications

Other Indications

  • • Rapid eGFR decline
  • • Proteinuria or hematuria
  • • Difficult-to-control hypertension
  • • Recurrent kidney stones
Learn More About Kidney Function

National Kidney Foundation

NKF guide to glomerular filtration rate and kidney function assessment

NIDDK Kidney Disease Info

National Institute of Diabetes and Digestive and Kidney Diseases information

KDIGO CKD Guidelines

Kidney Disease: Improving Global Outcomes clinical practice guidelines

Frequently Asked Questions

What is eGFR?
Estimated Glomerular Filtration Rate measures how well kidneys filter waste. Normal is > 90 mL/min/1.73 m². It is computed from serum creatinine, age, and sex using CKD-EPI or MDRD.
What do eGFR numbers mean?
> 90: normal. 60-89: mildly decreased (Stage 2). 45-59: mild-moderate (Stage 3a). 30-44: moderate-severe (Stage 3b). 15-29: severe (Stage 4). < 15: kidney failure (Stage 5).
What's the difference between CKD-EPI and MDRD?
CKD-EPI (2021) is more accurate, especially at higher GFR, and is now preferred. MDRD was developed for CKD patients and underestimates GFR in healthy people.
Can eGFR be wrong?
Yes. Extreme muscle mass, vegetarian diet, creatine supplements, acute kidney injury, and certain medications can distort creatinine and eGFR. Cystatin C-based equations may be more accurate in some cases.
How often should eGFR be monitored?
For CKD: every 3-12 months depending on stage. Diabetics / hypertensives: annually. After medications affecting kidneys: within 1-2 weeks. More frequently during acute illness.
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