LDL Cholesterol (Friedewald) Calculator

About this calculator

The Friedewald equation, published in 1972, estimates LDL ("bad") cholesterol from the three values a standard lipid panel measures directly — total cholesterol, HDL cholesterol, and triglycerides — using the formula LDL = Total Cholesterol − HDL − (Triglycerides / 5) when values are in mg/dL. Directly measuring LDL requires more expensive lab methods, so this formula-based estimate has been the default approach in routine cholesterol testing for decades.

The equation has one important limitation clinicians watch for: it becomes unreliable at high triglyceride levels, since the triglycerides/5 term is only a valid approximation of VLDL cholesterol within a normal triglyceride range. This calculator takes your total cholesterol, HDL, and triglycerides and returns your estimated LDL using the Friedewald formula.