Triglyceride to HDL Ratio Calculator (mg/dL and mmol/L)
The triglyceride to HDL ratio is your triglycerides divided by your HDL cholesterol. It’s an indirect clue to insulin resistance, not a diagnosis. In US units (mg/dL), 3.0 or more was the cut-off that best picked out insulin resistance in a 2003 Stanford study, and below 2.0 sits under most published cut-offs. In UK units (mmol/L), those same points are about 1.3 and 0.9. So a UK ratio of 2.0 equals about 4.6 in US units.
Units: triglycerides mg/dL × 0.0113 = mmol/L; HDL mg/dL × 0.0259 = mmol/L (Labcorp). A mmol/L ratio × 2.29 gives the mg/dL ratio.
Triglyceride to HDL ratio calculator
Enter both results from one lipid panel (lipid profile in the UK). It runs on your device; nothing is saved or sent.
TG/HDL ratio chart
Pins show the cut-offs from the main studies. Each defined insulin resistance its own way, which is one reason they disagree.
Sources: McLaughlin 2003; Li 2008; Salazar 2012; Murguía-Romero 2013; Mostafa 2012. Salazar and Murguía-Romero print no units; we read them as mg/dL ratios.
| Ratio in mg/dL (US) | Ratio in mmol/L (UK) | Band | What it usually means |
|---|---|---|---|
| Below 2.0 | Below 0.87 | Lower ratio | Below most published cut-offs |
| 2.0 to 2.99 | 0.87 to 1.30 | Grey zone | Above some cut-offs for women and some ethnic groups |
| 3.0 or more | 1.31 or more | Higher ratio | At or above the classic 3.0 cut-off; insulin resistance more likely |
How the TG/HDL ratio is calculated
Same units both in mg/dL, or both in mmol/L
Example: triglycerides 150 mg/dL and HDL 50 mg/dL. The same blood in UK units is 1.70 and 1.30 mmol/L:
UK: 1.70 ÷ 1.30 = 1.31
Same blood, two ratios. A triglyceride molecule weighs more than a cholesterol molecule, so the conversion factors differ (0.0113 and 0.0259). Multiply a mg/dL ratio by 0.436 to get the mmol/L ratio, or a mmol/L ratio by 2.29 to go back. Our unit converter handles single results.
Where 3.0 comes from. McLaughlin and colleagues at Stanford (2003) measured insulin resistance directly in 258 overweight adults without diabetes. A ratio of 3.0 or more picked out 64% of the insulin-resistant people and correctly cleared 68% of the rest. The abstract also prints 1.8 as the SI-unit cut-off, but 3.0 converts to 1.31 (1.8 would be about 4.1 in mg/dL). We use 1.31.
Rounding: the calculator divides your unrounded results and rounds the ratio to 2 decimals, halves up. It bands the ratio in the units you entered: 2.00 and 3.00 in mg/dL, 0.87 and 1.31 in mmol/L.
What your TG/HDL ratio means
Each band is a case file. NIDDK notes that blood fat levels may go up with insulin resistance. The usual footprint is raised triglycerides with low HDL, and AHA calls the ratio a summary measure of either or both. Like a detective reading footprints, the ratio never sees insulin itself.
Below 2.0 in mg/dL (below 0.87 in mmol/L)
- Triglycerides are low compared with HDL
- Below most published cut-offs
- A healthy blood fat pattern
- Possible false reassurance in Black adults (Metabolism 2010)
Check the rest: waist, blood pressure, glucose and HbA1c.
No guideline we checked uses this ratio. NIDDK says the test for insulin resistance is mainly used in research.
Ask: Do my other results point to insulin resistance? Is my LDL or lipoprotein(a) worth checking?
2.0 to 2.99 in mg/dL (0.87 to 1.30 in mmol/L)
- Below the classic 3.0
- At or above cut-offs some studies set for women (2.0 to 2.5), Black Americans (2.0) and South Asian men (2.8)
- Early insulin resistance, especially in women
- A non-fasting sample, recent alcohol or a sugary diet
Repeat fasting if this sample wasn’t. A HOMA-IR calculation adds fasting insulin to the picture.
Metabolic syndrome counts triglycerides above 150 mg/dL (1.7 mmol/L) and HDL below 40 mg/dL in men or 50 in women (1.0 or 1.3 mmol/L) as separate signs (NHLBI).
Ask: Should we repeat this fasting? Do I have any other signs of insulin resistance?
3.0 or more in mg/dL (1.31 or more in mmol/L)
- At or above McLaughlin’s 3.0
- In men, some studies set the bar higher, at 3.5 or 3.8
- Insulin resistance, prediabetes or type 2 diabetes
- Other causes of high triglycerides (see below)
Glucose and HbA1c, thyroid tests and kidney function if your doctor thinks they fit. If fatty liver is suspected, see FIB-4.
AHA/ACC 2018 lists metabolic syndrome and persistent triglycerides of 175 mg/dL (about 2.0 mmol/L) or more as factors that raise heart risk. The ratio isn’t on its list.
Ask: Could a secondary cause explain my triglycerides? Which lifestyle change would help me most?
What can throw off your ratio
- Not fasting. After usual meals, triglycerides rise by up to 0.3 mmol/L (26 mg/dL) on average, while HDL stays put (EAS/EFLM 2016). With HDL at 50 mg/dL, that adds about 0.5 to a mg/dL ratio. The main cut-off studies used fasting blood (McLaughlin 2003; Mostafa 2012).
- Mixing units. Comparing a mmol/L ratio with mg/dL cut-offs makes a UK result look better than it is: 1.3 in mmol/L is already at the classic 3.0.
- Alcohol, sugar and refined carbohydrates. Alcohol excess raises triglycerides, and AHA advises limiting added sugar and fructose.
- Exercise and weight loss. Lifestyle changes can cut triglycerides by 20 to 50% (AHA 2011).
- Other conditions and medicines: hypothyroidism, poorly controlled diabetes, kidney disease, steroids, thiazides, oral estrogen and pregnancy (AHA 2011).
- Lipid-lowering medicines. The Leicester study left out people taking them, so its cut-offs may not apply to you.
- Very high triglycerides. From 4.5 mmol/L (about 400 mg/dL), the triglyceride result itself needs attention. NICE (NG238) advises a repeat fasting test.
US vs UK: the mg/dL and mmol/L trap
Most online advice (“below 2 is good, above 3 is bad”) assumes mg/dL. UK labs (and those in Canada and Australia) report mmol/L, where the same cut-offs are about 0.9 and 1.3.
| Topic | US | UK |
|---|---|---|
| Units | mg/dL | mmol/L |
| Classic cut-off | 3.0 | 1.31 (about 1.3) |
| Lower point | 2.0 | 0.87 (about 0.9) |
| High triglycerides | 150 to 199 borderline high, 200 to 499 high, 500 or more very high (AHA 2011) | 4.5 to 9.9: repeat fasting; 10 to 20: urgent repeat within 5 to 14 days; over 20: urgent specialist review unless alcohol or poor glucose control explains it (NICE NG238) |
| Ratio on heart risk tools | Not among AHA/ACC risk enhancers | QRISK3 uses a cholesterol/HDL ratio, a different number |
Women, men and ethnicity
- Women and men: women tend to have more favorable blood fats (Baneu 2024), so cut-offs are lower. Salazar (Argentina) and Murguía-Romero (young Mexican adults) used 2.5 for women and 3.5 for men. In Leicester, the cut-offs were 2.0 for White European women and 3.8 for men.
- South Asian people: in Leicester, the cut-off for South Asian men was 2.8 (1.2 mmol/L). In South Asian women, it wasn’t linked with insulin resistance (Mostafa 2012). AHA/ACC counts South Asian ancestry as a heart risk-enhancing factor.
- Black adults: in one US study, African American adults had lower triglycerides, and the ratio predicted their insulin resistance poorly (Metabolism 2010). AHA (2011) links the ratio to insulin resistance in White people. A US study proposed 2.0 instead of 3.0 for Black adults (Li 2008).
- Pregnancy: triglycerides rise in pregnancy, especially in the third trimester (AHA 2011), so the usual cut-offs are hard to apply.
- Children: these cut-offs come from people aged 17 and over.
TG/HDL ratio vs HOMA-IR vs HbA1c
| Test | What it reads | Good to know |
|---|---|---|
| TG/HDL ratio | A blood fat pattern linked with insulin resistance | Uses a standard lipid panel. Weaker in Black adults and South Asian women. |
| HOMA-IR | Fasting glucose and fasting insulin | Needs an insulin test, and insulin assays aren’t standardized (McLaughlin 2003). |
| HbA1c | Average blood glucose over the past 3 months (NIDDK) | Diagnoses prediabetes and diabetes. It measures sugar, not insulin resistance. |
A 2024 review of 32 studies found no agreed cut-off: half proposed none at all. Only 2 of 17 studies that tested accuracy reached an area under the curve (AUC) of 0.8 or more, where 1.0 would be perfect (Baneu 2024).
Reading your ratio on a lab report or app
Look for triglycerides (TG, TRIG) and HDL cholesterol (HDL-C) on a lipid panel (US) or lipid profile (UK). US reports use mg/dL; UK reports and the NHS App use mmol/L. If a ratio is printed, check the label: cholesterol/HDL is a different calculation. Use one blood draw, and note whether you fasted.
When to get help urgently
- Call 911 (US) or 999 (UK) if you have sudden, severe pain in your tummy that spreads to your back, or comes with a fast heartbeat or trouble breathing. These can be signs of acute pancreatitis (NHS), a risk when triglycerides reach 10 mmol/L (880 mg/dL) or more (EAS/EFLM 2016).
- Triglycerides of 10 mmol/L (880 mg/dL) or more without symptoms: contact your doctor promptly. NICE advises an urgent repeat fasting test within 5 to 14 days.
TG/HDL ratio questions people ask
What is a good triglyceride to HDL ratio?
There’s no agreed ideal. In mg/dL, below 2.0 sits under most published cut-offs, and 3.0 or more often goes with insulin resistance.
What is a normal TG/HDL ratio in mmol/L?
Divide the mg/dL cut-offs by 2.29: 2.0 becomes 0.87 and 3.0 becomes 1.31. A UK ratio of 1.0 equals about 2.3 in US units.
Is a TG/HDL ratio of 3 bad?
In mg/dL, 3.0 is the classic cut-off for likely insulin resistance in overweight adults (McLaughlin 2003). In mmol/L, a ratio of 3 equals about 6.9 in mg/dL, which is high.
Can the ratio diagnose insulin resistance?
No. It’s a clue. In the Stanford study it missed about 1 in 3 insulin-resistant people.
Do I need to fast for the test?
Lipid panels often don’t need fasting, but the ratio’s cut-offs come from fasting blood. A non-fasting ratio can read higher.
How can I lower my TG/HDL ratio?
Lifestyle changes such as weight loss, more activity, less alcohol and less added sugar can cut triglycerides by 20 to 50% (AHA 2011). Your doctor will advise on medicines if needed.
How we wrote this page
Written and medically reviewed by Dr. Mustafa Sakr, MBBCh. Last reviewed: October 2026. The numbers come from the original studies and the guidance listed below. We update this page when guidance changes.
How the calculator works: it divides triglycerides by HDL, converts with Labcorp’s factors, rounds to 2 decimals and applies the bands above. Sex and background change only the notes. It flags non-fasting samples, unit mix-ups and very high triglycerides. It runs on your device and stores nothing.
References
- McLaughlin T, et al. Use of metabolic markers to identify overweight individuals who are insulin resistant. Ann Intern Med 2003;139:802–809. stanfordhealthcare.org
- Mostafa SA, et al. The association of the triglyceride-to-HDL cholesterol ratio with insulin resistance in White European and South Asian men and women. PLoS One 2012;7:e50931. journals.plos.org
- Li C, Ford ES, et al. Does the association of the TG/HDL-C ratio with fasting serum insulin differ by race/ethnicity? Cardiovasc Diabetol 2008;7:4. stacks.cdc.gov
- Should triglycerides and the TG/HDL-C ratio be used as surrogates for insulin resistance? Metabolism 2010;59:299–304. pubmed.ncbi.nlm.nih.gov
- Salazar MR, et al. TG/HDL ratio, insulin resistance and cardio-metabolic risk in men and women. Am J Cardiol 2012;109:1749–1753. bvsalud.org. Murguía-Romero M, et al. J Lipid Res 2013;54:2795–2799. doaj.org
- Baneu P, et al. The triglyceride/HDL ratio as a surrogate biomarker for insulin resistance. Biomedicines 2024;12:1493. mdpi.com
- Miller M, et al. Triglycerides and cardiovascular disease: AHA scientific statement. Circulation 2011;123:2292–2333. PDF. Summary: medicalxpress.com
- Nordestgaard BG, et al. Fasting is not routinely required for determination of a lipid profile (EAS/EFLM). Clin Chem 2016;62:930–946. eflm.eu (PDF)
- American College of Cardiology. 2018 AHA/ACC Multisociety Guideline on the Management of Blood Cholesterol: ten points to remember. acc.org
- NICE. Cardiovascular disease: risk assessment and reduction, including lipid modification (NG238), 2023, as applied by Liverpool University Hospitals pathology. rlbuht.nhs.uk. QRISK3: qrisk.org
- NHLBI. Metabolic syndrome: diagnosis. nhlbi.nih.gov
- NIDDK. Insulin resistance and prediabetes. niddk.nih.gov
- Labcorp. SI unit conversion table. labcorp.com. Mayo Clinic Laboratories: mayocliniclabs.com
- NHS. Acute pancreatitis. nhs.uk
This page is for education only and isn’t medical advice, a diagnosis or a substitute for your own doctor. Always interpret results with a qualified clinician. See our medical disclaimer.
