LDL Cholesterol Calculator (Friedewald)
LDL cholesterol is often not measured directly but calculated from a standard lipid panel using the Friedewald equation: LDL equals total cholesterol minus HDL cholesterol minus one fifth of triglycerides, in mg/dL. The triglyceride term estimates VLDL cholesterol. This calculator returns estimated LDL plus non-HDL cholesterol, and warns when triglycerides reach 400 mg/dL, where the equation becomes unreliable. Enter all values in mg/dL. LDL is a key target in cardiovascular risk management, but this tool is educational and not a substitute for clinical interpretation.
Friedewald formula
LDL = total cholesterol - HDL - (triglycerides / 5)
Non-HDL = total cholesterol - HDL
All values in mg/dL
Not valid when triglycerides are 400 mg/dL or higher
The triglycerides-over-5 term estimates VLDL cholesterol. At triglycerides of 400 mg/dL or above this approximation breaks down and a direct LDL measurement is needed; the calculator returns n/a in that range.
LDL cholesterol categories
- Below 100 mg/dL: optimal.
- 100 to 129 mg/dL: near optimal.
- 130 to 159 mg/dL: borderline high.
- 160 to 189 mg/dL: high.
- 190 mg/dL or above: very high.
LDL cholesterol: frequently asked questions
What is the Friedewald equation?
The Friedewald equation estimates LDL cholesterol as total cholesterol minus HDL cholesterol minus triglycerides divided by 5 (in mg/dL). The triglyceride-over-5 term approximates VLDL cholesterol. It is the long-standing method for calculating LDL from a standard lipid panel.
When is the Friedewald equation not valid?
It is unreliable when triglycerides are 400 mg/dL or higher, and it underestimates LDL at very low LDL levels. In those cases a direct LDL measurement or a newer equation should be used. This calculator flags triglycerides at or above 400.
What units does it use?
All inputs and the result are in mg/dL. If your panel reports in mmol/L, multiply cholesterol values by 38.67 and triglycerides by 88.57 to convert to mg/dL first, or use a panel reported in mg/dL.
What is a desirable LDL level?
General guidance considers LDL below 100 mg/dL optimal, 100 to 129 near optimal, 130 to 159 borderline high, 160 to 189 high, and 190 or above very high. Targets are individualized based on overall cardiovascular risk.
Is this medical advice?
No. This is an educational estimate of LDL from a lipid panel. Lipid targets and treatment decisions depend on your full cardiovascular risk and must be made with a clinician.
Official sources
- National Heart, Lung, and Blood Institute: Blood cholesterol.
- National Library of Medicine (NCBI): Friedewald LDL estimation literature.
Reviewed by the CalculatorHub team, edited by James Graham, 17 June 2026. See our methodology.