Cholesterol ratios are different formulas doctors can apply to the results of blood tests. They can help calculate a person’s risk of stroke, heart attack, and other cardiovascular diseases due to cholesterol.

Cholesterol is a fat-like substance within the body’s cells and foods from animals. A person’s body uses it to make vitamin D, hormones, and substances that help digestion.

However, excess cholesterol can harm the body. It can bind to other substances in the blood to form plaques. These plaques stick to artery walls, potentially causing blockages and leading to stroke or heart attack.

Health experts often use cholesterol panels to assess a person’s general health and their risk of stroke, heart attack, and other cardiovascular diseases.

This article discusses cholesterol ratios and how to calculate them. It also answers common questions about cholesterol tests and ratios.

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Cholesterol ratios are simple formulas that quickly assess a person’s general health and risk of cardiovascular diseases, such as coronary artery disease (CAD), using blood test results.

Lipid profiles, or lipid panels, are standard blood tests that doctors order to assess someone’s cardiovascular health. The blood tests measure the presence of different types of cholesterol and the proteins that carry them in the bloodstream.

Read on to learn more about cholesterol blood tests.

People can measure their heart health and risk of heart diseases using a combination of these cholesterol types to work out ratios.

Healthcare professionals may assess for the following types of cholesterol in a blood test:

Total cholesterol

Total cholesterol gives an overview of a person’s cholesterol and provides the total amount of cholesterol present in the body. This measurement combines both “good” and “bad” cholesterol levels. However, it does not provide sufficient information about someone’s risk of heart disease.

High-density lipoprotein (HDL)

HDL is the “good” cholesterol in the blood. It carries about one-third to one-fourthTrusted Source of free cholesterol away from the arteries to the liver, where the body begins expelling it. A high HDL can lower a person’s risk of heart disease and stroke and indicates good health. A person’s HDL should ideally be greater than 60 milligrams per deciliter (mg/dl)Trusted Source or at least 40 mg/dl.

Low-density lipoprotein (LDL)

LDL is also known as “bad” cholesterol. It accumulates in the artery walls and may cause blockages, leading to stroke and heart attack. LDL levels should be less than 130 mg/dl but ideally less than 100 mg/dlTrusted Source, according to the Centers for Diseases Control and Prevention (CDC).

Very low-density lipoprotein (VLDL)

VLDL is cholesterol that mainly transports triglycerides but can also contribute to plaque buildup in the arteries. VLDL levels should be less than 30 mg/dl.

Triglycerides

Triglycerides are the most common type of fat in the body. They store excess energy from a person’s diet. High triglyceride levels in combination with high LDL or low HDL may cause fatty buildup in the artery walls. Triglycerides should ideally be less than 150 mg/dlTrusted Source or at least less than 200 mg/dl.

People can use the following equations to calculate various cholesterol ratios:

Total cholesterol HDL ratio = total cholesterol ÷ HDL

To obtain their total cholesterol HDL ratio, a person can divide their total cholesterol level by their HDL level. Generally, higher ratios relate to a higher risk of health problems, such as heart disease.

For example: 240 (total cholesterol) ÷ 60 (HDL) = 4 (total cholesterol HDL ratio).

Health experts designate the following total cholesterol HDL ratios as follows:

  • ideal: under 3.5
  • good: under 5
  • bad: over 5

LDL-HDL ratio = LDL ÷ HDL

People can work out their LDL-HDL ratio by dividing their LDL level by their HDL level. This ratio is one of the most popular measures to see a person’s risk of heart disease.

For example: 100 (LDL) ÷ 55 (55) = 1.8 (LDL-HDL ratio).

Health experts designate the following LDL-HDL ratios as follows:

  • ideal: under 2.0
  • good: under 5.0
  • bad: over 5.0

A 2017 studyTrusted Source found that the LDL-HDL ratio had links to an increased risk of sudden cardiac death in the middle-aged male population.

Triglyceride HDL ratio = triglyceride level ÷ HDL

People can calculate their triglyceride HDL ratio by dividing their triglycerides by their HDL level. This is not a common measurement method, but it can help determine a person’s risk of heart disease. Some evidence also suggests that high triglyceride HDL ratios could indicate a higher risk of metabolic syndrome.

For example, 200 (triglyceride level) ÷ 55 (HDL) = 3.6 (triglyceride HDL ratio).

Health experts designate the following triglyceride HDL ratios as follows:

  • ideal: 2.0 or less
  • good: 4.0 to 6.0
  • bad: over 6.0 or above

Non-HDL cholesterol ratio = total cholesterol – HDL

As the name implies, this measure subtracts a person’s HDL level from their total cholesterol level so that it contains only all the “bad” cholesterol.

For example, 240 (total cholesterol) – 70 (HDL) = 170 (non-HDL cholesterol ratio).

Cholesterol is a crucial structural component in animal and human cell membranes. It is also essential for producing steroid hormones, bile acids, and vitamin D.

Low cholesterol, or hypocholesterolemia, may cause premature birth or low birth weight in pregnant people. It is also a risk factorTrusted Source for acute intracerebral hemorrhage, which refers to bleeding in the brain tissue. Rarely, it can also lead to:

However, high cholesterol levels, which doctors call hypercholesterolemia, could lead to atherosclerosis. Atherosclerosis involves the hardening and narrowing of arteries due to plaque buildup. This may cause other more severe conditions, such as:

The National Heart, Lung, and Blood InstituteTrusted Source recommends that individuals aged 9 to 11 years undergo blood cholesterol screening every 5 years.

Meanwhile, males aged 45 to 65 and females aged 55 to 65 should undergo screening every 1–2 years. Additionally, those older than 65 years should undergo annual screening.

A doctor may recommend more frequent screening if the test results do not fall within desirable ranges. They may also suggest more frequent testing for certain people, including those with the following conditions:

Health experts also recommend frequent screenings for those with a family history of these conditions.

Here are some answers to frequently asked questions about cholesterol ratios:

What is a good total cholesterol ratio?

Doctors consider a good total cholesterol HDL ratio to be 5, but a ratio under 3.5 is ideal.

What is a bad LDL-HDL ratio?

Typically, health experts consider a LDL-HDL ratio over 5 to be bad, with ratios lower than 5 good, and those below 2 to be ideal.

What is a healthy cholesterol ratio by age?

Generally, a healthy cholesterol ratio is below 5, with 3.5 being ideal. While there is no ideal cholesterol ratio by age, there are recommended healthy levels of cholesterol by age.

Does a person’s sex influence cholesterol?

People assigned female at birth (AFAB) generally have higher HDL cholesterol levels than those assigned male at birth (AMAB). Other factors such as pregnancy and menopause can also raise cholesterol levels.

However, even with higher HDL levels, the guidelines for cholesterol levels still provide a good target for managing cholesterol levels.

Many healthcare professionals use cholesterol ratios to quickly assess a person’s general health and give a picture of their risk of heart disease, stroke, and other cardiovascular diseases.

Having a high cholesterol level puts someone at risk of atherosclerosis, or the formation of plaques in the artery walls. Lifestyle changes, such as quitting smoking, drinking moderately, exercising more, and eating a nutritious diet, can help people with high cholesterol achieve their desired cholesterol levels.