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CardiacCalculated LDL-C

Calculated LDL Cholesterol Calculator (Friedewald)

Calculate LDL cholesterol with the traditional Friedewald equation.

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mg/dL
mg/dL

Choose the unit used by the entire lipid panel.

Calculated LDL-C

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About

This calculator applies the traditional Friedewald equation to total cholesterol, HDL-C, and triglycerides. It is intended for a lipid panel reported entirely in mg/dL or entirely in mmol/L. The estimate becomes less reliable as triglycerides rise and at lower LDL-C concentrations; it does not calculate cardiovascular risk or select a management plan.

Formula

mg/dL: LDL-C = Total cholesterol − HDL-C − Triglycerides / 5
mmol/L: LDL-C = Total cholesterol − HDL-C − Triglycerides / 2.2
Not reported when triglycerides are ≥400 mg/dL (≥4.52 mmol/L)

Interpretation

Applicability: All three inputs must use the selected unit. The result is a calculated LDL-C estimate, not a direct LDL measurement.

Limitation: No Friedewald value is shown at or above the triglyceride boundary. High triglycerides, dysbetalipoproteinemia, and low LDL-C can increase error.

Worked example: Total cholesterol 200, HDL-C 50, and triglycerides 150 mg/dL gives 200 − 50 − 150/5 = 120 mg/dL.

References

  1. Friedewald WT, Levy RI, Fredrickson DS. Estimation of LDL cholesterol without preparative ultracentrifugation. Clin Chem. 1972;18:499-502.
  2. Warnick GR, Knopp RH, Fitzpatrick V, Branson L. Estimating LDL-C by the Friedewald equation. Clin Chem. 1990;36:15-19.

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Disclaimer

Educational and informational reference only. Not intended to replace professional medical advice, diagnosis, treatment, or independent verification.