Calculate your calculated LDL levels using the Friedewald Formula
Note: This formula is most accurate when Triglycerides are under 400 mg/dL.
Your Calculated LDL:
Understanding Calculated LDL Cholesterol
LDL (Low-Density Lipoprotein) is often referred to as "bad" cholesterol. High levels of LDL can lead to a buildup of plaque in your arteries, increasing the risk of heart disease and stroke. While many modern labs measure LDL directly, many still use the Friedewald Formula to estimate it based on other lipids in your blood.
How the LDL Calculation Works
The standard equation used by most healthcare providers is:
LDL = Total Cholesterol – HDL – (Triglycerides / 5)
This formula works by subtracting the "good" cholesterol (HDL) and a portion of your triglycerides (which represents VLDL cholesterol) from your total cholesterol number. However, this calculation is only valid if your triglycerides are below 400 mg/dL.
LDL Level Interpretations
LDL Level (mg/dL)
Category
Below 100
Optimal
100 – 129
Near Optimal / Above Optimal
130 – 159
Borderline High
160 – 189
High
190 and above
Very High
Example Calculation
If your lab results show:
Total Cholesterol: 210 mg/dL
HDL: 55 mg/dL
Triglycerides: 150 mg/dL
The math would be: 210 – 55 – (150 / 5) = 210 – 55 – 30 = 125 mg/dL (Near Optimal).
Medical Disclaimer: This calculator is for educational purposes only and is not a substitute for professional medical advice. Always consult with your doctor to interpret your cholesterol results.
function calculateLDL() {
var total = parseFloat(document.getElementById('totalCholesterol').value);
var hdl = parseFloat(document.getElementById('hdlCholesterol').value);
var tri = parseFloat(document.getElementById('triglycerides').value);
var resultArea = document.getElementById('ldl-result-area');
var valDisplay = document.getElementById('ldl-value');
var interpretationDisplay = document.getElementById('ldl-interpretation');
if (isNaN(total) || isNaN(hdl) || isNaN(tri)) {
alert('Please enter valid numbers for all fields.');
return;
}
if (tri >= 400) {
alert('Warning: The Friedewald formula is not considered accurate when Triglycerides are 400 mg/dL or higher. Direct LDL measurement is recommended.');
}
// Friedewald Formula: LDL = TC – HDL – (TG/5)
var ldl = total – hdl – (tri / 5);
ldl = Math.round(ldl);
resultArea.style.display = 'block';
valDisplay.innerText = ldl + ' mg/dL';
var color = ";
var text = ";
if (ldl = 100 && ldl = 130 && ldl = 160 && ldl = 190) {
interpretationDisplay.style.backgroundColor = '#721c24';
} else {
interpretationDisplay.style.backgroundColor = 'transparent';
}
resultArea.scrollIntoView({ behavior: 'smooth', block: 'nearest' });
}