Your cholesterol ratio is total cholesterol divided by HDL cholesterol. A lower ratio is better. In large population studies it predicts heart disease better than total cholesterol does by itself.
Even so, the ratio is not what treatment decisions are built on. Guidelines focus on LDL cholesterol and related measures, because those are what trials have lowered. Think of the ratio as a quick summary of your panel, not a verdict.
Key takeaways
- Divide total cholesterol by HDL cholesterol to get the ratio; the units cancel out.
- Among simple measures that include HDL, the ratio was the best predictor of fatal heart disease in a very large pooled study.
- Two people with the same ratio can have very different LDL cholesterol levels.
- Raising HDL to improve the ratio is not a proven way to lower risk.
- Treatment goals are set in terms of LDL cholesterol, not the ratio.
How to calculate it
Find total cholesterol and HDL cholesterol on your lipid panel and divide. A total of 200 mg/dL with an HDL of 50 mg/dL gives a ratio of 4.0. Because both numbers are in the same units, the ratio comes out the same whether your lab reports in mg/dL or mmol/L.
Some reports print it for you as "Chol/HDL ratio". Some also list an LDL-to-HDL ratio, which works on the same idea with a different top number.
What counts as high
There is no cut-off from a US guideline. The figures below come from one expert review of lipid ratios, which set its risk levels and targets for people without known heart disease as follows.
| Total-to-HDL ratio | Men | Women |
|---|---|---|
| Level the review treats as raised risk | Above 5.0 | Above 4.5 |
| Target the review suggests | Below 4.5 | Below 4.0 |
For people without known heart disease, that review put the risk level at a ratio above 5.0 in men and above 4.5 in women.1
Your lab may print a different reference range. Treat any of these numbers as rough guides. They are not thresholds for starting or stopping treatment.
What the ratio captures
The ratio packs two pieces of information into one figure: how much cholesterol you carry overall, and how much of it sits in HDL particles, which do not form plaque. A high ratio means a large share of your cholesterol is in the particles that do.
The evidence that this predicts disease is solid. A pooled analysis of 61 studies, with HDL results for about 150,000 participants, found that the total-to-HDL ratio was the strongest predictor of death from ischemic heart disease among simple measures involving HDL, and more than twice as informative as total cholesterol.2
The Framingham study points the same way. Among 3,322 middle-aged adults followed for a median of 15 years, each standard-deviation rise in the ratio was linked with about a 39% higher risk of coronary heart disease in both men and women, and a more elaborate ratio based on apolipoproteins did no better.3
So the ratio is not folklore. As a quick read on a standard panel, it is one of the better summaries available.
What it misses
The same ratio can hide different situations. A total of 160 with an HDL of 40 gives 4.0. So does a total of 280 with an HDL of 70. The second person is carrying far more cholesterol in plaque-forming particles, and the ratio cannot tell you that.
A high HDL can flatter it. People with high HDL do have fewer heart attacks on average, but that seems to be a marker, not a cause. In a large genetic study, people who inherited higher HDL cholesterol had no lower risk of heart attack than those who did not.4
That finding matters here. A ratio that looks good mainly because HDL is high is less reassuring than one that looks good because the other cholesterol is low. We go into this in is higher HDL always better?
It leaves things out entirely. The ratio says nothing about Lp(a), the number of particles, inflammation, blood sugar or blood pressure.
Why guidelines use other measures
Total and HDL cholesterol still matter. They are inputs to the PREVENT risk calculator, entered as two separate numbers, not as a ratio.
Treatment is a different matter. The 2018 US cholesterol guideline framed statin treatment goals as percentage reductions in LDL cholesterol, not as a ratio to reach.5 The reason is practical. The trials that proved a benefit lowered LDL cholesterol, and the genetic evidence above gives little reason to expect the same from raising HDL.
When clinicians want one number that sums up all the plaque-forming cholesterol, they tend to use non-HDL cholesterol, which is total minus HDL, or an ApoB test, which counts the particles.
What a Cardio Res-Q assessment adds to the ratio
If your ratio is borderline, or looks fine while something else worries you, the useful next step is to measure what the ratio leaves out. The Cardio Res-Q Comprehensive Assessment ($775) includes ApoB, Lp(a), hs-CRP, homocysteine, insulin, glucose and A1c, the Cleveland Heart cardiac panel and Dr. Varano's clinical evaluation. The Enhanced Assessment ($999) adds a CIMT ultrasound and a coronary calcium score.
To decide between the two, read Comprehensive vs. Enhanced: which to choose. You can book from the Cardio Res-Q program page.
Are You a Candidate for Cardio Res-Q?
Three quick questions about the risk factors we screen for. Your answers stay between you and the clinic.
Frequently asked questions
What is a good cholesterol ratio?
Lower is better. One expert review suggests aiming below 4.5 for men and below 4.0 for women without known heart disease, but these are not official US targets. Your LDL cholesterol and overall risk matter more than the ratio.
My ratio is good but my LDL is high. Which one counts?
The LDL result still counts. A good ratio driven by high HDL does not cancel out a high LDL cholesterol. Guidelines base treatment decisions on LDL and overall risk, so raise it with your clinician.
Is the total-to-HDL ratio the same as the LDL-to-HDL ratio?
No, though they behave similarly. One uses total cholesterol on top and the other uses LDL cholesterol. In the Framingham study both predicted coronary heart disease about equally well.
Do I need to fast for the ratio to be valid?
Not usually. Total and HDL cholesterol change very little after an ordinary meal. Fasting matters more for triglycerides and for tests such as insulin and glucose.
Related reading
This article is for general education and is not medical advice. Decisions about testing and medication should be made with your clinician. If you have chest pain or other symptoms of a heart attack, call 911.
