Cholesterol Ratio Calculator
Turn a lipid panel into the ratios doctors watch. Enter total cholesterol, HDL, and triglycerides in mg/dL to get your total-to-HDL ratio, non-HDL cholesterol, the TG-to-HDL ratio, and where the ratio falls.
Example: with Total cholesterol (mg/dL) 200 · HDL cholesterol (mg/dL) 50 · Triglycerides (mg/dL, optional) 150 → Total-to-HDL ratio: 4 : 1 (total ÷ HDL).
- Non-HDL cholesterol150 mg/dL non-HDL
- Triglyceride-to-HDL ratio3 : 1 (TG ÷ HDL)
- Ratio bandTotal:HDL Average
Computed by the calculator below using its default values. Change any input to see your own numbers.
The total-to-HDL ratio is total cholesterol ÷ HDL; lower is better. Because it is a ratio, it reads the same whether the panel is in mg/dL or mmol/L.
What the ratios add to a lipid panel
The total-to-HDL cholesterol ratio compresses two numbers into one risk signal: divide total cholesterol by HDL, and a lower result is better because it means more of your cholesterol is the protective HDL kind. A total of 200 with an HDL of 50 gives a 4.0 ratio. General guidance treats under about 3.5 as ideal and 5 or above as higher risk, though your real risk depends on the whole picture — blood pressure, smoking, diabetes, and age.
Two companion numbers help. Non-HDL cholesterol (total minus HDL) captures all the atherogenic particles in one figure, with under 130 mg/dL often considered good. The triglyceride-to-HDL ratio is used in research as a rough proxy for insulin resistance, where lower is better. Because these are ratios, they read the same in mg/dL or mmol/L.
How it’s calculated
Total-to-HDL ratio = total cholesterol ÷ HDL. Non-HDL cholesterol = total − HDL. Triglyceride-to-HDL ratio = triglycerides ÷ HDL. Ratios are unitless, so mg/dL and mmol/L give the same value. Bands: < 3.5 ideal, 3.5–5 average, 5–9 higher, ≥ 9 high (general AHA/Framingham usage).
Ratios summarize but do not replace the full panel or your overall cardiovascular risk; the TG-to-HDL proxy for insulin resistance is research-based, not a diagnosis. Not medical advice.
Total-to-HDL ratio bands
| Total : HDL | Interpretation |
|---|---|
| Below 3.5 | Ideal / low risk |
| 3.5 - 5.0 | Average |
| 5.0 - 9.0 | Higher risk |
| Above 9 | High risk |
General AHA/Framingham ranges; individual targets depend on overall risk.
Common mistakes
- Swapping the order — it is total ÷ HDL, so a higher HDL lowers (improves) the ratio.
- Chasing the ratio while ignoring a high LDL or non-HDL that also needs attention.
- Comparing your ratio to another lab's cutoffs without noting they are general, not personal.
- Reading the TG-to-HDL number as a diagnosis of insulin resistance rather than a rough proxy.
Frequently asked questions
How do I calculate my cholesterol ratio?
Divide total cholesterol by HDL. A total of 200 mg/dL and HDL of 50 mg/dL give a ratio of 4.0. Lower ratios are generally better.
What is a good cholesterol ratio?
Under about 3.5 is often called ideal and 5 or higher higher-risk, but these are general guides. Your target depends on your full risk profile.
Does the ratio change in mmol/L?
No. Because both numbers are in the same unit, the ratio is unitless and identical whether the panel is reported in mg/dL or mmol/L.
Should I make decisions from this alone?
No. Ratios are one piece of the picture. Discuss your full lipid panel and overall risk with your clinician before changing anything.