Creatinine Clearance Calculator
Creatinine clearance (CrCl) is a measure of how well your kidneys are filtering creatinine, a waste product from muscle metabolism, from your blood. It's a vital indicator of kidney function. This calculator helps estimate your CrCl using common formulas. Please consult your healthcare provider for medical advice.
Understanding Creatinine Clearance
Creatinine is a byproduct of normal muscle breakdown. Healthy kidneys efficiently filter creatinine from the blood and excrete it in urine. When kidney function declines, the kidneys are less effective at filtering creatinine, leading to higher levels in the blood. Creatinine clearance (CrCl) is a test that estimates this filtering rate. A lower CrCl generally indicates poorer kidney function.
Why is Creatinine Clearance Important?
Monitoring CrCl is crucial for:
- Detecting and diagnosing kidney disease in its early stages.
- Assessing the severity of kidney damage.
- Tracking the progression of kidney disease over time.
- Adjusting medication dosages, as many drugs are cleared by the kidneys.
- Evaluating the effectiveness of treatments for kidney conditions.
Common Formulas for Creatinine Clearance
Several formulas are used to estimate creatinine clearance. The most common ones are the Cockcroft-Gault equation and the MDRD (Modification of Diet in Renal Disease) study equation. For simplicity and common clinical use, this calculator utilizes the Cockcroft-Gault equation, which requires serum creatinine, age, sex, and body weight.
The Cockcroft-Gault Equation:
- For men: CrCl = [(140 – age) × body weight (kg)] / [72 × serum creatinine (mg/dL)]
- For women: CrCl = [(140 – age) × body weight (kg) × 0.85] / [72 × serum creatinine (mg/dL)]
It's important to note that the Cockcroft-Gault equation typically uses actual body weight. However, for individuals with obesity, adjusted or ideal body weight might be considered, though this calculator uses the provided body weight.
Interpreting the Results
Normal creatinine clearance varies by age, sex, and body size, but generally, values above 90 mL/min are considered normal for adults. Values below 60 mL/min for three months or more may indicate chronic kidney disease (CKD). The specific interpretation should always be done by a healthcare professional in the context of the individual's overall health status.
function calculateCreatinineClearance() { var serumCreatinine = parseFloat(document.getElementById("serumCreatinine").value); var age = parseFloat(document.getElementById("age").value); var bodyWeight = parseFloat(document.getElementById("bodyWeight").value); var gender = document.getElementById("gender").value; var resultDiv = document.getElementById("result"); resultDiv.innerHTML = ""; // Clear previous results if (isNaN(serumCreatinine) || isNaN(age) || isNaN(bodyWeight)) { resultDiv.innerHTML = "Please enter valid numeric values for all fields."; return; } if (serumCreatinine <= 0 || age <= 0 || bodyWeight <= 0) { resultDiv.innerHTML = "Please enter positive values for serum creatinine, age, and body weight."; return; } var creatinineClearance = 0; var denominator = 72 * serumCreatinine; if (gender === "male") { creatinineClearance = ((140 – age) * bodyWeight) / denominator; } else { // female creatinineClearance = ((140 – age) * bodyWeight * 0.85) / denominator; } // Ensure result is not negative (can happen with very high serum creatinine or specific age/weight inputs) if (creatinineClearance < 0) { creatinineClearance = 0; } resultDiv.innerHTML = "Estimated Creatinine Clearance (CrCl): " + creatinineClearance.toFixed(2) + " mL/min"; }