Skip to main content
CalcIntel

Updated · Methodology: named formula library

eGFR Kidney Function Calculator

Estimated glomerular filtration rate (CKD-EPI).

Estimated Creatinine Clearance
80.5 mL/min

Cockcroft-Gault: ((140 − 55) × 75 kg × 1) / (72 × 1.1) = 80.5 mL/min.

Age55
Weight75 kg
Serum creatinine1.1 mg/dL
Sex factor1.0 (male)
CrCl80.5 mL/min
Data sources: CalcIntel Formula Library

Why This Calculation Matters

The eGFR Kidney Function Calculator turns a well-known health formula into an instant lookup. It's most useful when you're tracking a number over time or comparing yourself against published reference ranges from bodies like the CDC, NIH, or WHO. Use it as one data point among many, not a diagnosis.

How to Use This Calculator

  • Enter your values in the input fields, each one has a label and help text explaining what to type.
  • Results appear instantly as you type; there's no "calculate" button to press.
  • Change any input to compare scenarios side by side.

All math happens in your browser. Nothing you type is sent to a server, saved, or shared.

Reading Your Result

A single number tells you less than a trend. Track this value over weeks or months rather than obsessing over day-to-day variation. Hydration, sleep, and timing can all shift short-term readings without reflecting any real change.

How to Use

Enter values in the fields on the left. Results update as you type, no submit button needed.

Understanding Results

Each output shows the calculated figure plus a breakdown of contributing inputs. Compare scenarios by editing any value.

Accuracy Notes

Every eGFR Kidney Function Calculator on CalcIntel uses a documented formula. Results are estimates, real outcomes depend on assumptions and market conditions not captured in a simplified calculation.

Formula

Metric: BMI = kg / m². Imperial: BMI = (lb / in²) × 703. WHO categories: underweight <18.5, normal 18.5-24.9, overweight 25-29.9, obese ≥30.

Worked Example

50 yo male, 70 kg, Cr 1.0

age
50
weight
70
creatinine
1
sex
male
Result
88 mL/min

((140 − 50) × 70 × 1.0) / (72 × 1.0) = 88 mL/min.

When to Use This Calculator

  • Track personal health metrics over time alongside guidance from your clinician.
  • Understand how lifestyle changes may influence a given health number.
  • Compare values against recognized reference ranges from CDC, NIH, or WHO.

Limitations & Common Mistakes

  • Not a substitute for medical advice. Always consult a qualified clinician for anything that affects your care.
  • Population-level formulas don't account for individual medical history, medications, or body composition nuances.
  • Reference ranges evolve, use current CDC/NIH/WHO values when accuracy matters.

Frequently Asked Questions

What is the Cockcroft-Gault formula?

CrCl (mL/min) = ((140 − age) × weight in kg × sex factor) / (72 × serum creatinine in mg/dL). Sex factor: 1.0 for male, 0.85 for female. Published by Cockcroft and Gault in 1976; widely used for kidney function estimation and drug dosing.

What's a normal CrCl range?

Normal: > 90 mL/min. Mild reduction: 60–89. Moderate (CKD stage 3): 30–59. Severe (stage 4): 15–29. Kidney failure (stage 5): < 15. Adjust drug dosing for patients below 60 mL/min.

Cockcroft-Gault vs MDRD vs CKD-EPI?

Cockcroft-Gault uses age, weight, sex, and serum creatinine — useful for drug dosing. MDRD and CKD-EPI are body-surface-area normalized and preferred for staging CKD. For simple drug dosing, Cockcroft-Gault remains the FDA reference standard.

When is Cockcroft-Gault inaccurate?

In extremes of body weight (very obese, very thin), unstable creatinine (acute kidney injury, rhabdomyolysis), pregnancy, and amputation. In these cases, measured 24-hour urine creatinine clearance is the gold standard.

Related Calculators

More Health

Source: BLS Consumer Price Index, 2026.