Free tool
LDL Calculator (Friedewald Equation)
Most labs don't measure LDL directly — they calculate it from Total Cholesterol, HDL, and Triglycerides using the Friedewald equation. Enter the same three numbers to see how it's derived, or to double-check a result.
This calculator is for informational purposes only and is not a substitute for medical advice. Always consult your doctor about your lab results.
The Friedewald Equation
LDL = Total Cholesterol − HDL − (Triglycerides ÷ 5)
The triglycerides-over-5 term estimates VLDL cholesterol, since VLDL isn't measured directly on a standard panel either. This is why the equation only holds up when triglycerides are below roughly 400 mg/dL — above that, the estimate becomes unreliable and labs switch to direct LDL measurement.
| LDL (mg/dL) | Category |
|---|---|
| Under 100 | Optimal |
| 100–129 | Near optimal |
| 130–159 | Borderline high |
| 160–189 | High |
| 190+ | Very high |
When the Estimate Isn't Reliable
If your triglycerides are 400 mg/dL or higher, the Friedewald equation systematically underestimates LDL. In that case, ask your doctor about a direct LDL measurement instead of relying on the calculated value — including this one.