Last updated October 5, 2026 · Report an error
The Friedewald equation estimates LDL cholesterol from a standard lipid panel without a direct LDL measurement: LDL = Total Cholesterol - HDL - (Triglycerides / 5), all in mg/dL. It is not considered valid when triglycerides exceed 400 mg/dL, so this calculator blocks the calculation above that threshold. This calculator is for general reference and educational purposes only — it is not a medical diagnosis. Consult a doctor for actual lipid panel interpretation.
How it works
Enter total cholesterol, HDL, and triglycerides (all mg/dL). The tool estimates VLDL as triglycerides/5, then subtracts HDL and estimated VLDL from total cholesterol.
- Enter total cholesterol (mg/dL).
- Enter hDL cholesterol (mg/dL).
- Enter triglycerides (mg/dL).
- Click Calculate to see your results.
Examples
Total 200, HDL 50, triglycerides 150 (mg/dL)
LDL = 200 - 50 - (150/5) = 200 - 50 - 30 = 120 mg/dL.
Who should use it
- Estimating LDL from a routine lipid panel that doesn't include a direct LDL measurement.
- Understanding how LDL is typically calculated on a standard lab report.
Industry applications
- Clinical chemistry and lab reporting
- Primary care and cardiology reference
Advantages
- Widely used, decades-old published formula requiring no extra lab test beyond a standard lipid panel.
- Free and instant compared to ordering a direct LDL measurement.
Limitations
- Not valid when triglycerides exceed 400 mg/dL.
- Less accurate than a direct LDL measurement, especially at higher triglyceride levels.
Common mistakes to avoid
- Using a non-fasting lipid panel, since triglycerides (and thus the LDL estimate) can rise substantially after eating.
- Applying the formula despite triglycerides above 400 mg/dL, where it is not considered valid.
Best practices
- Use a fasting lipid panel when possible for a more reliable Friedewald estimate.
Tips
- If your triglycerides are high, ask your doctor about a direct LDL measurement instead of the calculated estimate.