The LDL Cholesterol Calculator estimates low-density lipoprotein (LDL) levels to assess cardiovascular risk. Choose between the Friedewald formula (fasting samples) or Martin/Hopkins method (non-fasting) for accuracy.
Formulas
1. Friedewald Formula (Most Common):
LDL (mg/dL) =
Total Cholesterol −
HDL −
(
Triglycerides
5
)
*Friedewald formula (valid when Triglycerides < 400 mg/dL)
Limitations:
- Requires fasting triglycerides <400 mg/dL.
- Less accurate if triglycerides >200 mg/dL.
2. Martin/Hopkins Method (More Accurate):
LDL =
Total Cholesterol −
HDL −
(
Triglycerides
Adjustable Factor
)
Adjustable Factor:
| Triglycerides (mg/dL) | Factor |
|---|---|
| 75–99 | 3.1 |
| 100–149 | 3.4 |
| 150–199 | 3.8 |
| 200–299 | 4.5 |
| 300–399 | 5.6 |
3. NIH Equation (For mmol/L)
LDL (mmol/L) =
Total Cholesterol −
HDL −
(
Triglycerides
2.2
)
*SI units version: Factor 2.2 used for mmol/L conversion (vs 5 for mg/dL)
🧮 LDL Cholesterol Calculator
⚙️ Select Unit System:
How to Use the Calculator
- Input Values:
- Total Cholesterol (mg/dL or mmol/L).
- HDL (mg/dL or mmol/L).
- Triglycerides (mg/dL or mmol/L).
- Select Formula: Friedewald (default) or Martin/Hopkins.
- Calculate LDL.
Example (Friedewald Formula)
- Total Cholesterol = 200 mg/dL
- HDL = 50 mg/dL
- Triglycerides = 150 mg/dL
LDL (mg/dL) =
Total Cholesterol −
HDL −
(
Triglycerides
5
)
*Friedewald formula (valid when Triglycerides < 400 mg/dL)
LDL (mg/dL) =
200 −
50 −
(
150
5
)
LDL (mg/dL) =
200 −
50 −
(30) −
= 120 (mg/dL)
Normal LDL Ranges
| Category | LDL (mg/dL) | Risk Level |
|---|---|---|
| Optimal | <100 | Low |
| Near Optimal | 100–129 | Moderate |
| Borderline High | 130–159 | High |
| High | 160–189 | Very High |
| Very High | ≥190 | Extreme |
Clinical Significance
| LDL Level | Interpretation |
|---|---|
| <70 | Ideal for high-risk patients (e.g., CVD, diabetes) |
| >160 | Increased atherosclerosis risk; consider statins |
Key Notes
- Triglyceride Limits:
- Friedewald formula invalid if triglycerides ≥400 mg/dL (use direct LDL measurement).
- Non-Fasting Samples:
- Use Martin/Hopkins for non-fasting triglycerides.
- Unit Conversions:
- 1 mmol/L = 38.67 mg/dL (for cholesterol/triglycerides).
Comparison of Methods
| Method | Accuracy | Triglyceride Range | Fasting Required? |
|---|---|---|---|
| Friedewald | Moderate | <400 mg/dL | Yes |
| Martin/Hopkins | High | 75–399 mg/dL | No |
| Direct LDL | Most accurate | Any | No |
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The content on LabTestsGuide.com is for informational and educational purposes only. We do not guarantee the accuracy, completeness, or timeliness of the information provided. Always consult qualified healthcare professionals for medical advice, diagnosis, or treatment. LabTestsGuide.com is not liable for any decisions made based on the information on this site.
