A lipid panel on its own gives you three or four numbers: total cholesterol, HDL ("good") cholesterol, LDL ("bad") cholesterol, and triglycerides. The number that actually predicts heart attack risk best, however, is the relationship between them — specifically the cholesterol ratio, also called the total-to-HDL ratio. This calculator takes the numbers from your blood test and returns that ratio along with your non-HDL cholesterol, your LDL/HDL ratio, and a plain-language risk category so you can see at a glance where you stand.
The formula is deliberately simple: divide your total cholesterol by your HDL cholesterol. A ratio below 5.0 is generally considered desirable; between 5.0 and 9.9 is average; 10.0 or higher signals elevated heart disease risk. Plug in your results and every figure below updates instantly.
How to Use
- Enter your Total Cholesterol — the sum of HDL, LDL, and roughly 20% of your triglycerides as reported on the lab slip, in mg/dL.
- Enter your HDL Cholesterol. This must be a positive number; if your HDL is 0, the ratio cannot be computed because dividing by zero is undefined.
- Optionally enter your LDL Cholesterol. If you leave it blank, the calculator still works and simply skips the LDL/HDL output.
- Read the highlighted Cholesterol Ratio. A lower number is better because it means your total cholesterol is small relative to your protective HDL.
- Check the Risk Category label: Desirable (<5.0), Average (5.0–9.9), or High heart disease risk (>=10.0).
- Note your Non-HDL Cholesterol (total minus HDL), which clinicians increasingly use as a secondary target; for most adults it should stay under 130 mg/dL, and under 100 mg/dL for people with established heart disease.
The result card also shows your LDL/HDL ratio when an LDL value is provided. As a rough rule, an LDL/HDL ratio below 2.5 is desirable, and above 4.0 is high.
Examples
Example 1 — Typical adult. A 45-year-old woman gets a lipid panel: total 200 mg/dL, HDL 50 mg/dL, LDL 130 mg/dL. Her cholesterol ratio is 200 / 50 = 4.0, which falls in the Desirable category. Her non-HDL cholesterol is 200 − 50 = 150 mg/dL, and her LDL/HDL ratio is 130 / 50 = 2.6. Despite her total cholesterol being right at the "borderline" cutoff of 200, her strong HDL means her overall ratio is healthy — which is exactly why the ratio matters more than total cholesterol alone.
Example 2 — High risk. A 55-year-old man has total 300 mg/dL, HDL 30 mg/dL, and LDL 200 mg/dL. His ratio is 300 / 30 = 10.0, landing in the High heart disease risk category. His non-HDL is 270 mg/dL and his LDL/HDL is 6.7. Even though his total and LDL numbers are bad on their own, the ratio makes the full picture obvious: low HDL combined with very high LDL multiplies his risk far more than either number would suggest in isolation.
Example 3 — Borderline average. A person with total 240 mg/dL and HDL 40 mg/dL has a ratio of 240 / 40 = 6.0, which is Average. Raising HDL by just 5 mg/dL through exercise and quitting smoking pushes the ratio to 240 / 45 = 5.3 — still average, but clearly moving in the right direction. This is the practical insight the ratio gives you: small changes in HDL can swing your category more than large changes in total.
The Formula and the Cutoffs
The cholesterol ratio is straightforward division:
Ratio = Total Cholesterol ÷ HDL Cholesterol
The tiers below come from decades of Framingham Heart Research and are still used by the American Heart Association:
- Below 5.0 — Desirable. Your total cholesterol is small relative to your protective HDL.
- 5.0 to 9.9 — Average. Risk is moderate; lifestyle changes (diet, exercise, smoking cessation) and sometimes medication are worth discussing with a clinician.
- 10.0 or higher — High heart disease risk. This combination of high total and low HDL is one of the strongest single lipid predictors of myocardial infarction.
Non-HDL cholesterol is calculated as total − HDL. It captures every atherogenic particle — LDL, VLDL, remnant cholesterol — and is particularly useful in people with elevated triglycerides. The LDL/HDL ratio is LDL ÷ HDL; below 2.5 is generally considered favorable.
FAQ
What is a good cholesterol ratio?
A total-to-HDL ratio below 5.0 is generally considered desirable. For reference, a ratio of 4.0 (total 200, HDL 50) is healthy, while a ratio of 10.0 (total 300, HDL 30) signals high heart disease risk. Because higher HDL is protective, the same total cholesterol can yield very different ratios depending on your HDL.
Is total cholesterol or the ratio more important?
The ratio is more predictive of heart attack risk than total cholesterol alone. Someone with a total of 220 but an HDL of 60 has a ratio of 3.7 (desirable), while someone with a total of 200 and an HDL of 30 has a ratio of 6.7 (average to high). Total cholesterol by itself can hide a weak HDL, whereas the ratio exposes it.
What is non-HDL cholesterol?
Non-HDL cholesterol is your total cholesterol minus your HDL. It represents all the cholesterol carried by "bad" particles — LDL, VLDL, and remnants. For most adults the target is under 130 mg/dL; for people with diabetes or established cardiovascular disease the tighter target is under 100 mg/dL.
What if my HDL is very low or zero?
If your HDL is zero, the calculator returns an error because dividing by zero is undefined. Clinically, an HDL below 30–40 mg/dL is itself a risk factor regardless of the ratio, and extremely low HDL (rare genetic conditions) should be evaluated by a physician rather than reduced to a single number.
How can I improve my cholesterol ratio?
You improve the ratio by raising HDL, lowering LDL, or both. Proven levers include regular aerobic exercise, quitting smoking, replacing trans fats and refined carbs with unsaturated fats and fiber, moderate alcohol intake (if any), and — when indicated — statin or fibrate medication prescribed by a clinician. Because the ratio is a division, even a small HDL increase can move your category noticeably.
Does this calculator replace a lipid panel?
No. It takes the numbers from a lipid panel and computes the ratio. It does not measure anything, and it does not account for other risk factors such as blood pressure, diabetes, smoking, family history, or obesity. Use it to understand your lab results and to have a more informed conversation with your doctor.
Disclaimer
This cholesterol ratio calculator is provided for informational purposes only and is not medical advice. It is not intended to diagnose, treat, cure, or prevent any disease, and it should not be used as a substitute for professional clinical judgment. Cholesterol targets vary by age, sex, personal cardiovascular risk, diabetes status, and family history. Always discuss your lipid panel results, your ratio, and any treatment decisions with a qualified healthcare provider before starting, stopping, or changing any medication or lifestyle regimen.