LDL Cholesterol Calculator
Calculate LDL cholesterol using the Friedewald equation: LDL = Total Cholesterol − HDL − (Triglycerides/5). Optimal LDL is below 100 mg/dL; above 190 mg/dL is very high risk.
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⚠️For informational purposes only — not medical advice. Consult a healthcare professional before acting on results.
LDL cholesterol is calculated using the Friedewald equation: LDL = Total Cholesterol − HDL − (Triglycerides ÷ 5). Optimal LDL is below 100 mg/dL; above 190 mg/dL indicates very high cardiovascular risk. AHA/ACC 2018 guidelines.
Sources: AHA/ACC 2018, Friedewald 1972, CDC.
Key Takeaways
- • Friedewald: LDL = TC − HDL − (TG ÷ 5); valid when TG <400 mg/dL
- • LDL <100 mg/dL is optimal for most adults; targets vary by ASCVD risk
- • Non-HDL cholesterol (TC − HDL) is an alternative target, especially with high TG
- • Fasting 9-12 hours before lipid panel improves accuracy
Did You Know?
How Does LDL Calculation Work?
Friedewald Equation
LDL = Total Cholesterol − HDL − (Triglycerides ÷ 5). The TG/5 estimates VLDL cholesterol.
Limitations
Unreliable when TG ≥400 mg/dL. Non-fasting samples can inflate TG and underestimate LDL.
Alternatives
Direct LDL measurement, Martin-Hopkins, or Sampson-NIH equations for high TG.
Expert Tips
LDL Categories (AHA/ACC)
| LDL (mg/dL) | Category | Risk |
|---|---|---|
| <100 | Optimal | Low |
| 100-129 | Near Optimal | Low-Moderate |
| 130-159 | Borderline High | Moderate |
| 160-189 | High | High |
| ≥190 | Very High | Very High |
Frequently Asked Questions
What is LDL cholesterol?
LDL (low-density lipoprotein) is the "bad" cholesterol that can build up in artery walls. Optimal LDL is below 100 mg/dL. Above 190 mg/dL indicates very high cardiovascular risk per AHA/ACC guidelines.
How is LDL calculated?
The Friedewald equation: LDL = Total Cholesterol − HDL − (Triglycerides ÷ 5). Valid when triglycerides are below 400 mg/dL. Requires fasting lipid panel.
What is a good LDL level?
Optimal: <100 mg/dL. Near optimal: 100-129. Borderline high: 130-159. High: 160-189. Very high: ≥190 mg/dL. Targets vary by cardiovascular risk.
When is the Friedewald formula inaccurate?
When triglycerides exceed 400 mg/dL, or with non-fasting samples. Direct LDL measurement or Martin-Hopkins/Sampson equations may be used instead.
How often should LDL be checked?
Adults 20+ every 5 years if low risk. Every 1-2 years if risk factors present. Every 4-12 weeks when starting or adjusting statin therapy.
What affects LDL levels?
Diet (saturated fat), genetics, weight, exercise, medications (statins), thyroid disease, and liver function. Fasting 9-12 hours before the test improves accuracy.
Key Statistics
Official Data Sources
⚠️ Disclaimer: This calculator is for educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider.