The triglyceride to HDL ratio is a simple calculation from a standard lipid panel, but the answer depends on which units your lab reports. Most of the confusion online comes from quoting a cutoff without saying which unit it was in.
Quick answer: The ratio is not unit-independent. A ratio calculated in mmol/L is about 2.3 times smaller than the same person’s ratio in mg/dL. In mg/dL, a ratio under about 2 is often described as favorable and a ratio of about 3 or higher has been associated with insulin resistance in several studies. The matching mmol/L figures are roughly 0.9 and 1.3. Cutoffs vary by study, sex, and ancestry, and the ratio is a clue, not a diagnosis.
How to calculate it
Divide triglycerides by HDL, both in the same units. Example in mg/dL: triglycerides 150 and HDL 50 give 3.0. The same blood in mmol/L is triglycerides 1.69 and HDL 1.29, which gives 1.31. Our triglyceride/HDL ratio calculator works in either unit so you do not have to convert.
Converting units
- Triglycerides: mmol/L x 88.57 = mg/dL
- HDL cholesterol: mmol/L x 38.67 = mg/dL
- Ratio: mg/dL ratio / 2.29 = mmol/L ratio
Mixing units is the most common error. If a result shows triglycerides of 1.7 and HDL of 50, one is in each system and the ratio is meaningless until you convert. Here are common values side by side.
| Triglycerides (mg/dL) | Triglycerides (mmol/L) | HDL (mg/dL) | HDL (mmol/L) |
|---|---|---|---|
| 100 | 1.13 | 40 | 1.03 |
| 150 | 1.69 | 50 | 1.29 |
| 200 | 2.26 | 60 | 1.55 |
| 500 | 5.65 | 70 | 1.81 |
Worked examples in both units
Each row below was computed from the formulas above. Notice how the mg/dL ratio is always about 2.3 times the mmol/L ratio.
| Triglycerides | HDL | Ratio (mg/dL) | Ratio (mmol/L) | Same blood, different story |
|---|---|---|---|---|
| 90 mg/dL (1.02 mmol/L) | 70 mg/dL (1.81 mmol/L) | 1.29 | 0.56 | Low triglycerides, high HDL |
| 100 mg/dL (1.13 mmol/L) | 60 mg/dL (1.55 mmol/L) | 1.67 | 0.73 | Both in comfortable ranges |
| 150 mg/dL (1.69 mmol/L) | 50 mg/dL (1.29 mmol/L) | 3.00 | 1.31 | Triglycerides at the 150 line, HDL moderate |
| 200 mg/dL (2.26 mmol/L) | 40 mg/dL (1.03 mmol/L) | 5.00 | 2.18 | High triglycerides and low HDL |
| 250 mg/dL (2.82 mmol/L) | 35 mg/dL (0.91 mmol/L) | 7.14 | 3.12 | Both components unfavorable |
| 240 mg/dL (2.71 mmol/L) | 80 mg/dL (2.07 mmol/L) | 3.00 | 1.31 | Same ratio as row three, but triglycerides are high |
The last row is the reason to look at the ingredients as well as the ratio. Triglycerides of 150 mg/dL or higher count as one of the five metabolic syndrome markers, and HDL below 40 mg/dL in men or below 50 mg/dL in women counts as another. A ratio can look acceptable when one of those components is flagged.
What the ratio is thought to reflect
High triglycerides with low HDL is a common pattern in insulin resistance, and the ratio has been used as a quick marker of it in research. A frequently cited example is a 2003 study by McLaughlin and colleagues in the Annals of Internal Medicine, which examined whether triglyceride and HDL measures could identify insulin resistance in 258 overweight adults without diabetes. In some studies the ratio has tracked with more direct measures such as HOMA-IR and with cardiovascular risk. It is less reliable across different populations, and women, who tend to have higher HDL, often run lower ratios at the same level of risk. Read more in our triglyceride/HDL ratio guide, and see what low HDL means.
Why cutoffs disagree
You will see published thresholds in mg/dL and mmol/L, for different sexes, ancestries, and outcomes (insulin resistance, fatty liver, heart disease). A cutoff built to flag insulin resistance in overweight adults may not apply to a lean young woman or an older man with diabetes. A cutoff quoted without units is nearly useless. That is why this page gives approximate rules of thumb in both units and stresses trends over single readings.
The ratio in the context of metabolic syndrome
Triglycerides and HDL are two of the five markers used to define metabolic syndrome. Under the commonly used U.S. criteria, having three or more of the five counts.
| Marker | Common U.S. threshold |
|---|---|
| Waist | 40 in (102 cm) or more in men; 35 in (88 cm) or more in women |
| Triglycerides | 150 mg/dL (1.7 mmol/L) or higher, or on treatment for high triglycerides |
| HDL cholesterol | Below 40 mg/dL (1.0 mmol/L) in men or below 50 mg/dL (1.3 mmol/L) in women, or on treatment |
| Blood pressure | 130/85 or higher, or on treatment |
| Fasting glucose | 100 mg/dL (5.6 mmol/L) or higher, or on treatment |
The ratio compresses two of these markers into one number. It is convenient, but it cannot replace the full checklist, which is why our metabolic syndrome calculator counts all five. The MedlinePlus metabolic syndrome page lists the criteria.
Reading the ratio over time: an example
Here is a fictional series of four fasting panels, each calculated in mg/dL.
| Panel | Triglycerides | HDL | Ratio (mg/dL) | Ratio (mmol/L) |
|---|---|---|---|---|
| 1 | 210 | 38 | 5.53 | 2.41 |
| 2 | 180 | 42 | 4.29 | 1.87 |
| 3 | 150 | 48 | 3.13 | 1.36 |
| 4 | 120 | 52 | 2.31 | 1.01 |
Over four panels, triglycerides fell and HDL rose, so the ratio fell from 5.5 to 2.3. Because both components moved, the ratio exaggerates the change relative to either alone. That is a feature when you want a single trend line and a risk when someone treats the drop as a measure of progress by itself. Also notice the ratio still sits above 2 at the end, which is where the “favorable” rule of thumb starts. Whether that matters is a question for the clinician reading the whole panel.
Women and men: why the same ratio can mean different things
HDL is higher on average in women, so women often have lower ratios at similar triglyceride levels. For example, triglycerides of 130 mg/dL with HDL of 70 mg/dL give a ratio of 1.86, while the same triglycerides with HDL of 45 give 2.89. Both people are under the 150 mg/dL triglyceride line, yet their ratios land on opposite sides of the “about 2” rule of thumb. Researchers have proposed sex-specific and ancestry-specific cutoffs for this reason, but none is universally adopted. Use the ratio as a trend and a prompt for a conversation.
How it compares with other estimates
| Estimate | Inputs | Strength | Weakness |
|---|---|---|---|
| Triglyceride/HDL ratio | Triglycerides and HDL | Uses a standard lipid panel; simple | Unit confusion; cutoffs vary; sensitive to meals |
| TyG index | Triglycerides and fasting glucose | Adds glucose; no insulin needed | Triglycerides are noisy; cutoffs vary |
| HOMA-IR | Fasting glucose and insulin | Uses insulin, closer to the mechanism | Needs insulin; assays differ |
| Remnant cholesterol | Total, HDL, LDL | Highlights triglyceride-rich particles | Depends on LDL calculation |
See TyG index vs HOMA-IR for those two in detail and what remnant cholesterol is for the last row.
Where to find your numbers and how to check the units
Most patient portals show triglycerides and HDL in the results table with the unit printed next to each value, such as mg/dL or mmol/L. If the column header says only “result”, look at the reference range: a triglyceride reference range of “below 150” is mg/dL, while “below 1.7” is mmol/L. HDL ranges follow the same pattern, with 40 to 60 typical in mg/dL and 1.0 to 1.6 in mmol/L. If your portal shows only a ratio your clinic calculated, ask which unit it used before comparing it with any cutoff you read online. When two labs report in different systems, write both versions in your notes so you can compare across years.
Things that change the result
Triglycerides swing with your last meal, alcohol, and recent weight changes, which is why fasting vs nonfasting matters. HDL is steadier but changes with activity, smoking, some medicines, and weight. Repeat the calculation on a comparable test before drawing conclusions. If you want a second view, the TyG index calculator adds fasting glucose, and the HOMA-IR calculator uses insulin. The MedlinePlus triglycerides page covers the standard ranges.
For what moves triglycerides, see diet for high triglycerides and the complete guide to high triglycerides. Do not start, stop, or change any medicine because of a ratio.
Common mistakes
- Dividing triglycerides in one unit by HDL in another.
- Quoting a cutoff without its unit.
- Using a non-fasting sample and comparing it with earlier fasting ones.
- Ignoring the components when the ratio looks acceptable.
- Treating the ratio as a diagnosis of insulin resistance.
- Comparing results from different labs without checking the units each uses.
Questions to bring to your appointment
- Which units does your lab use, and was my sample fasting?
- How does my ratio compare with my other markers?
- Would a direct insulin resistance test change anything?
- When should we repeat the panel?
- Do my triglycerides or my HDL deserve more attention than the ratio?
Frequently asked questions
What is a good triglyceride to HDL ratio?
There is no single official target. In mg/dL units, a ratio under about 2 is often described as favorable, and values around 3 or higher have been used in studies as a flag for insulin resistance. In mmol/L units the matching figures are roughly 0.9 and 1.3. Cutoffs differ by study, sex, and ancestry.
Why does my ratio look different in a calculator that uses mmol/L?
Because the ratio is not unit-independent. Triglycerides convert at 88.57 and HDL at 38.67, so a ratio in mmol/L is the mg/dL ratio divided by about 2.29. A ratio of 3.0 in mg/dL is 1.31 in mmol/L for the same blood.
Do men and women have the same cutoff?
Studies often find women have higher HDL and therefore lower ratios at the same level of metabolic risk, so some researchers propose sex-specific cutoffs. There is no single agreed set. Look at your ratio together with your HDL, triglycerides, and other metabolic markers.
Does the ratio need a fasting sample?
Fasting is better because triglycerides rise after meals and alcohol. A non-fasting ratio can look higher. If you compare over time, keep the fasting status the same.
Can the ratio be normal when my triglycerides are high?
Yes, if HDL is also high. For example, triglycerides of 240 mg/dL with HDL of 80 mg/dL give a ratio of 3.0, the same as triglycerides of 150 with HDL of 50. The ratio can hide a high triglyceride value, so read the components too.
Is the ratio a diagnosis of insulin resistance?
No. It is a clue that has tracked with insulin resistance in some studies. A clinician looks at the ratio with waist size, blood pressure, glucose or A1C, liver tests, and family history.
Which units should I use?
Use whichever your lab reports, and use the same units for both values. If your report mixes systems, convert before dividing. Our calculator accepts either unit so you do not have to convert.
About the author: Charles Kirkland is the founder of Metabolic Clarity Labs and author of The Journey Back. He is not a physician. This is general education, not a medically reviewed treatment plan.
Sources checked October 31, 2026. Discuss personal decisions with a qualified clinician. Do not start, stop, or change prescribed treatment based on this article.
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