Martin-Hopkins LDL Calculator
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mg/dL
About this Calculator
The Martin-Hopkins equation estimates LDL cholesterol (LDL-C) from total cholesterol, HDL cholesterol, and triglyceride levels. Unlike the Friedewald equation, it uses an adjustable factor to improve LDL-C estimation accuracy, particularly at low LDL-C levels.
Non-HDL = Total cholesterol − HDL
LDL = Non-HDL − (Triglycerides ÷ Adjustable factor)
This calculator uses the original Martin-Hopkins method for triglyceride levels from 7 to below 400 mg/dL. Results are estimates and should be interpreted alongside other lipid measurements and cardiovascular risk factors.
Overview
The Martin-Hopkins equation estimates low-density lipoprotein cholesterol (LDL-C) using values from a standard lipid profile.
Unlike the traditional Friedewald equation, which uses a fixed divisor of 5 to estimate very-low-density lipoprotein cholesterol (VLDL-C), the Martin-Hopkins equation uses an adjustable factor based on triglyceride and non-HDL cholesterol levels. This approach can improve LDL-C estimation accuracy, particularly when LDL-C levels are low.
The method was developed and validated by Martin and colleagues in a study published in JAMA in 2013.
Equations
Non-HDL cholesterol = Total cholesterol - HDL cholesterol
LDL cholesterol = Non-HDL cholesterol - (Triglycerides ÷ Adjustable factor)
The adjustable factor represents the estimated ratio of triglycerides to VLDL cholesterol (TG:VLDL-C). It is selected from a lookup table based on:
- Triglyceride concentration (mg/dL)
- Non-HDL cholesterol concentration (mg/dL)
Adjustable Factor Lookup Table
The Martin-Hopkins method uses a 180-cell lookup table to determine the appropriate adjustable factor based on triglyceride and non-HDL cholesterol concentrations.
- Rows: Triglyceride ranges (mg/dL)
- Columns: Non-HDL cholesterol ranges (mg/dL)
| Triglycerides (mg/dL) | <100 | 100-129 | 130-159 | 160-189 | 190-219 | ≥220 |
|---|---|---|---|---|---|---|
| 7-49 | 3.5 | 3.4 | 3.3 | 3.3 | 3.2 | 3.1 |
| 50-56 | 4.0 | 3.9 | 3.7 | 3.6 | 3.6 | 3.4 |
| 57-61 | 4.3 | 4.1 | 4.0 | 3.9 | 3.8 | 3.6 |
| 62-66 | 4.5 | 4.3 | 4.1 | 4.0 | 3.9 | 3.9 |
| 67-71 | 4.7 | 4.4 | 4.3 | 4.2 | 4.1 | 3.9 |
| 72-75 | 4.8 | 4.6 | 4.4 | 4.2 | 4.2 | 4.1 |
| 76-79 | 4.9 | 4.6 | 4.5 | 4.3 | 4.3 | 4.2 |
| 80-83 | 5.0 | 4.8 | 4.6 | 4.4 | 4.3 | 4.2 |
| 84-87 | 5.1 | 4.8 | 4.6 | 4.5 | 4.4 | 4.3 |
| 88-92 | 5.2 | 4.9 | 4.7 | 4.6 | 4.4 | 4.3 |
| 93-96 | 5.3 | 5.0 | 4.8 | 4.7 | 4.5 | 4.4 |
| 97-100 | 5.4 | 5.1 | 4.8 | 4.7 | 4.5 | 4.3 |
| 101-105 | 5.5 | 5.2 | 5.0 | 4.7 | 4.6 | 4.5 |
| 106-110 | 5.6 | 5.3 | 5.0 | 4.8 | 4.6 | 4.5 |
| 111-115 | 5.7 | 5.4 | 5.1 | 4.9 | 4.7 | 4.5 |
| 116-120 | 5.8 | 5.5 | 5.2 | 5.0 | 4.8 | 4.6 |
| 121-126 | 6.0 | 5.5 | 5.3 | 5.0 | 4.8 | 4.6 |
| 127-132 | 6.1 | 5.7 | 5.3 | 5.1 | 4.9 | 4.7 |
| 133-138 | 6.2 | 5.8 | 5.4 | 5.2 | 5.0 | 4.7 |
| 139-146 | 6.3 | 5.9 | 5.6 | 5.3 | 5.0 | 4.8 |
| 147-154 | 6.5 | 6.0 | 5.7 | 5.4 | 5.1 | 4.8 |
| 155-163 | 6.7 | 6.2 | 5.8 | 5.4 | 5.2 | 4.9 |
| 164-173 | 6.8 | 6.3 | 5.9 | 5.5 | 5.3 | 5.0 |
| 174-185 | 7.0 | 6.5 | 6.0 | 5.7 | 5.4 | 5.1 |
| 186-201 | 7.3 | 6.7 | 6.2 | 5.8 | 5.5 | 5.2 |
| 202-220 | 7.6 | 6.9 | 6.4 | 6.0 | 5.6 | 5.3 |
| 221-247 | 8.0 | 7.2 | 6.6 | 6.2 | 5.9 | 5.4 |
| 248-292 | 8.5 | 7.6 | 7.0 | 6.5 | 6.1 | 5.6 |
| 293-399 | 9.5 | 8.3 | 7.5 | 7.0 | 6.5 | 5.9 |
| 400-13975 | 11.9 | 10.0 | 8.8 | 8.1 | 7.5 | 6.7 |
Clinical note: The original Martin-Hopkins equation is intended for triglyceride levels below 400 mg/dL. Although the lookup table shown above includes a higher triglyceride stratum, this does not establish clinical validity for calculations in that range. Triglyceride levels of 400-799 mg/dL require a separately validated method, such as the extended Martin-Hopkins equation. The original equation should not be used to calculate LDL-C at triglyceride levels of 400 mg/dL or higher.
Reference
Martin SS, Blaha MJ, Elshazly MB, et al. Comparison of a Novel Method vs the Friedewald Equation for Estimating Low-Density Lipoprotein Cholesterol Levels From the Standard Lipid Profile. JAMA. 2013;310(19):2061-2068.
How to use
How to Use the Martin-Hopkins LDL Calculator
- Enter your total cholesterol and select mg/dL or mmol/L.
- Enter your HDL cholesterol and select the appropriate unit.
- Enter your triglyceride level and select mg/dL or mmol/L.
- Click Calculate to view your estimated LDL cholesterol, non-HDL cholesterol, and the adjustable triglyceride-to-VLDL cholesterol factor used.
Important Notes
- All values must be non-negative, and HDL cholesterol cannot exceed total cholesterol.
- Triglycerides below 400 mg/dL: The original Martin-Hopkins equation is applicable.
- Triglycerides 400-799 mg/dL: The extended Martin-Hopkins equation may be used if specifically implemented.
- Triglycerides ≥800 mg/dL: Calculated LDL cholesterol is generally unreliable. Consider alternative lipid assessments.
Disclaimer: This calculator provides an estimated LDL cholesterol value and does not replace clinical evaluation. Results should be interpreted alongside the complete lipid profile and cardiovascular risk factors.