Cholesterol Ratio Calculator — TC/HDL, LDL/HDL, TG/HDL
Enter your total cholesterol, HDL, LDL and triglyceride readings (in mg/dL from a standard lipid panel) to calculate three clinical cholesterol ratios and see where they fall in cardiovascular risk ranges.
mg/dL
mg/dL
mg/dL
mg/dL
Primary cardiovascular risk marker — optimal < 3.5
- 1
LDL / HDL ratio
120 ÷ 55 = 2.18Atherogenic burden relative to protective transport — aim for < 2.5. - 2
TG / HDL ratio
100 ÷ 55 = 1.82 - 3
Total / HDL ratio
200 ÷ 55 = 3.64
How does this calculator work?
Divide total cholesterol by HDL to get the primary cardiovascular risk marker: TC/HDL < 3.5 is optimal, 3.5–5.0 is average risk, > 5.0 is high risk. Also compute LDL/HDL (aim < 2.5) and TG/HDL in mg/dL (aim < 2.0 as an insulin-resistance proxy). All values must be in mg/dL; consult your doctor for interpretation.
Formula
How this is calculated
A standard lipid panel measures four values: total cholesterol (TC), high-density lipoprotein (HDL, the "good" cholesterol that transports lipids away from arteries), low-density lipoprotein (LDL, the "bad" cholesterol that deposits in arterial walls), and triglycerides (TG, a form of fat circulating in blood). Doctors use the absolute values but also their ratios, because ratios capture the balance between protective and harmful fractions better than any single number.
The TC/HDL ratio is the most widely validated: values below 3.5 are considered optimal, 3.5–5.0 average risk, and above 5.0 high risk — these thresholds are general guidelines used by the American Heart Association and major European guidelines, not hard cut-offs. The LDL/HDL ratio reflects atherogenic burden relative to protective transport; below 2.5 is generally considered favourable. The TG/HDL ratio (when both are in mg/dL) is used as a proxy for insulin resistance and small-dense LDL particle count; values below 2.0 are considered low risk.
All inputs are assumed to be in mg/dL as reported on a US-style lipid panel. If your lab reports in mmol/L, use the Cholesterol Units Calculator to convert first. These ratios are population-level screening tools and must be interpreted alongside age, blood pressure, smoking status, and other risk factors by a clinician.
Frequently asked questions
Below 3.5 is considered optimal, 3.5–5.0 is average cardiovascular risk, and above 5.0 is elevated risk. The ratio matters because it captures how much of your total cholesterol is the protective HDL fraction — a high HDL can offset a moderately high total cholesterol.
When both are in mg/dL, a TG/HDL ratio below 2.0 suggests a predominance of large fluffy LDL particles (less harmful); above 3.5 suggests small dense LDL (more atherogenic) and possible insulin resistance. Note: this cut-off does NOT apply when using mmol/L — for mmol/L the threshold is approximately 0.87.
Convert to mg/dL before entering: multiply total cholesterol, HDL and LDL by 38.67, and triglycerides by 88.57. Alternatively, use the Cholesterol Units Calculator on this site, then come back with the converted values.
TG we-Calculate Editorial Team. (2026). Cholesterol Ratio Calculator — TC/HDL, LDL/HDL, TG/HDL [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/cholesterol-ratio-calculator
TG we-Calculate Editorial Team. "Cholesterol Ratio Calculator — TC/HDL, LDL/HDL, TG/HDL." TG we-Calculate. 2026. https://we-calculate.com/calculator/cholesterol-ratio-calculator.
TG we-Calculate Editorial Team, "Cholesterol Ratio Calculator — TC/HDL, LDL/HDL, TG/HDL," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/cholesterol-ratio-calculator
@misc{wecalculate_cholesterol_ratio_calculator, title = {Cholesterol Ratio Calculator — TC/HDL, LDL/HDL, TG/HDL}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/cholesterol-ratio-calculator}}, year = {2026}, note = {TG we-Calculate} }
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