TG/HDL Ratio: A Simple Way to Spot Hidden Metabolic Risk
Use two numbers from your lipid panel to estimate insulin resistance risk and long-term cardiovascular strain.
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Calculated on your device
Evidence-based
Peer-reviewed research
Actionable
Improves with lifestyle
Who is this especially useful for?
- •Your LDL looks "fine," but family history is concerning
- •A1C and glucose are "normal," but energy and cravings aren't
- •You want early signals, not late diagnoses
TG/HDL is not a diagnosis — it's an early pattern signal.
You get your cholesterol results back. Your doctor glances at the LDL number, maybe mentions it's "a bit high," and moves on. But buried in that same lab report is a ratio that research suggests might be even more important — and it rarely gets discussed.
The triglyceride-to-HDL ratio (TG/HDL) is calculated by dividing your triglycerides by your HDL cholesterol. It takes about three seconds to calculate, yet mounting evidence shows it's one of the strongest predictors of cardiovascular disease and metabolic dysfunction.
Calculate yours now
Enter your triglyceride and HDL values from your most recent lab work into our free TG/HDL calculatorto see where you stand.
What is the TG/HDL Ratio?
The math is simple: take your triglyceride level and divide it by your HDL ("good") cholesterol.
Triglycerides are fats circulating in your blood. Your body produces them from excess calories — especially sugar, refined carbs, and alcohol. High levels signal that your metabolism isn't processing fuel efficiently.
HDL cholesterol acts like a cleanup crew, removing excess cholesterol from your arteries and transporting it back to the liver. Higher is generally better.
Example Calculation
150
Triglycerides (mg/dL)
50
HDL (mg/dL)
Your TG/HDL Ratio
3.0
How to Find These Numbers on Your Lab Report
Both values come from a standard lipid panel — one of the most common blood tests.
Triglycerides
Usually listed as "Triglycerides" or "TG" in the lipid panel section
HDL Cholesterol
Listed as "HDL" or "HDL-C" — this is the "good" cholesterol
💡 Check your units: US labs typically use mg/dL, while European labs often use mmol/L. Our calculator handles both.
I have my numbers →Calculation Methodology: Why Units Matter
The TG/HDL ratio isn't as simple as dividing two numbers — at least not when different units are involved.
Different conversion factors
Triglycerides and HDL cholesterol use different conversion factors between mg/dL and mmol/L:
Because these factors differ by a ratio of ~2.29, calculating the TG/HDL ratio directly in mmol/L gives a different number than calculating in mg/dL.
Example: Same values, different ratios
Consider someone with TG = 1.5 mmol/L and HDL = 1.3 mmol/L:
Direct mmol/L ratio: 1.5 ÷ 1.3 = 1.15
After conversion to mg/dL: (1.5 × 88.57) ÷ (1.3 × 38.67) = 132.86 ÷ 50.27 = 2.64
The mg/dL-based ratio is approximately 2.3× higher than the mmol/L-based ratio.
Why we use mg/dL-based thresholds
The clinical thresholds for TG/HDL ratio were established in studies using mg/dL measurements. To ensure consistent interpretation regardless of your lab's unit system, our calculator:
- Converts mmol/L values to mg/dL using the appropriate conversion factors
- Calculates the ratio using these standardized values
- Applies the validated clinical thresholds
This way, whether your lab reports in mg/dL (common in the US) or mmol/L (common in Europe and elsewhere), you get the same risk assessment.
Three Perspectives on TG/HDL
Different health paradigms interpret these thresholds differently:
Based on population averages. Many labs don't flag until > 3.5.
Functional medicine targets tighter ranges for prevention.
Often improves dramatically on carb restriction. Transient rises during adaptation are normal.
Three Perspectives on TG/HDL
Different health paradigms interpret these thresholds differently:
mg/dL (US)
Standard Medical
Based on population averages. Many labs don't flag until > 3.5.
Research Consensus
Functional medicine targets tighter ranges for prevention.
Metabolic Optimization
Often improves dramatically on carb restriction. Transient rises during adaptation are normal.
mmol/L (International)
Standard Medical
Based on population averages. Many labs don't flag until > 1.5.
Research Consensus
Functional medicine targets tighter ranges for prevention.
Metabolic Optimization
Often improves dramatically on carb restriction. Transient rises during adaptation are normal.
Learn more about these paradigms
A note on ethnic differences
Studies suggest these thresholds work well for Caucasian, Hispanic, and Asian populations. For African Americans, the TG/HDL ratio may be less predictive. Consider using HOMA-IR as a complementary marker.
Why This Ratio Matters More Than You'd Think
For decades, LDL cholesterol has dominated conversations about heart health. But large-scale studies suggest the TG/HDL ratio often predicts cardiovascular risk better than LDL alone.
43%
Higher CVD Risk
Top vs. bottom TG/HDL category
Chen et al., 2022 — 207,000 participants
29%
Higher CVD Risk
Top vs. bottom TG/HDL quartile
UK Biobank, 2023 — 403,000 participants
79%
Sensitivity
For insulin resistance detection
McLaughlin et al., 2003
The research is compelling
A 2022 meta-analysis combined data from 13 studies with over 207,000 participants. Those with the highest TG/HDL ratios had 43% higher risk of cardiovascular events compared to those with the lowest ratios.
An even larger 2023 study followed 403,000 people from the UK Biobank for over eight years. Those in the top quartile for TG/HDL ratio had a 29% higher risk of developing heart disease.
McLaughlin's landmark 2003 study validated the TG/HDL ratio against the gold-standard euglycemic clamp, finding that a ratio ≥3.0 identifies insulin-resistant individuals with 79% sensitivity.
What doctors often focus on
LDL Cholesterol
What studies suggest matters
TG/HDL Ratio
(often more predictive)
The Hidden Connection: Insulin Resistance
Here's something crucial: an elevated TG/HDL ratio is one of the strongest markers of insulin resistance — the metabolic dysfunction at the root of type 2 diabetes, metabolic syndrome, and much cardiovascular disease.
What an elevated TG/HDL ratio often signals
- Insulin resistance — cells not responding well to insulin
- Small, dense LDL particles — the type more likely to cause plaque
- Increased cardiovascular risk — independent of LDL levels
- Metabolic dysfunction — often years before diabetes develops
How to Improve Your TG/HDL Ratio
The good news: TG/HDL ratio responds very well to lifestyle changes. Triglycerides in particular can shift within weeks of targeted changes.
Lower Your Triglycerides
- •Cut refined carbs and sugars — dramatic improvement in 2-4 weeks
- •Limit alcohol — even moderate drinking raises triglycerides
- •Add omega-3s — fatty fish 2-3x per week
- •Move after meals — a 15-minute walk helps
Raise Your HDL
- •Exercise regularly — consistency matters more than intensity
- •Choose healthy fats — olive oil, avocado, nuts
- •Stop smoking — powerful way to raise HDL
- •Prioritize sleep — 7-9 hours makes a real difference
How fast can you see results?
Triglycerides respond quickly — often within 2-4 weeks of dietary changes. HDL takes longer, typically 2-3 months. Many people see meaningful TG/HDL ratio improvement within 4-8 weeks.
What About Insulin Spikes? Why TG/HDL Still Matters
You might have heard that insulin "spikes" after meals are actually healthy. That's true — and it doesn't change what your TG/HDL ratio tells you. Here's why.
Different timeframes, different information
A strong insulin response when you eat reflects healthy pancreatic function. Your beta cells detect rising blood sugar and release insulin quickly. This acute response happens in minutes and is a sign your system is working well.
Your TG/HDL ratio measures something else entirely: the cumulative effects of how your cells have been responding to insulin over weeks to months. When chronic insulin resistance develops, it disrupts lipid metabolism in predictable ways:
- Your liver produces more triglycerides
- HDL particles are cleared more rapidly
- LDL particles shift toward the smaller, denser type
These changes accumulate gradually. They're not about what happens in the 30 minutes after lunch.
Both can be true at once
This is the key insight: you can have excellent meal-time insulin secretion AND elevated TG/HDL at the same time. They measure different stages of metabolic health.
Think of it like this:
- Acute insulin response = checking if your thermostat responds when you adjust it (immediate function)
- TG/HDL ratio = your average monthly heating bill (cumulative efficiency)
Both tell you something important, but they're measuring different things.
The research supports this
A 2024 genetic study of over 400,000 UK Biobank participants identified 114 genetic locations associated with TG:HDL-C ratio as a marker of insulin resistance. This validation is independent of any debate about acute insulin responses — it confirms that TG/HDL captures real, chronic metabolic dysfunction with genetic underpinnings.
The bottom line
When someone says "insulin spikes aren't bad," they're right about acute responses. But your TG/HDL ratio reveals whether chronic insulin resistance has progressed enough to affect your lipid metabolism — and that matters for your long-term cardiovascular and metabolic health.
Key Takeaways
- TG/HDL ratio is calculated by dividing triglycerides by HDL cholesterol
- Large studies (400,000+ participants) show it predicts heart disease — even after accounting for LDL
- High TG/HDL strongly correlates with insulin resistance and small, dense LDL particles
- Standard tests don't show it — you need to calculate it yourself
- Lifestyle changes work — cutting refined carbs and exercising can improve it within weeks
Related Tools
TG/HDL Calculator
Calculate your ratio instantly
HOMA-IR Calculator
Measure insulin resistance
WHtR Calculator
Waist-to-height ratio
References
- Gaziano JM et al. (1997). Fasting triglycerides, HDL, and risk of myocardial infarction. Circulation. PMID: 9355888
- McLaughlin T et al. (2003). Use of metabolic markers to identify insulin-resistant individuals. Ann. Intern. Med. PMID: 14623617
- Hanak V et al. (2004). TG/HDL ratio for prediction of LDL phenotype B. Am. J. Cardiol. PMID: 15246908
- Chen Z et al. (2022). Triglyceride to HDL-C ratio and cardiovascular events. Nutr. Metab. Cardiovasc. Dis. PMID: 34953633
- Che B et al. (2023). TG/HDL-C ratio and CVD risk: UK Biobank analysis. Cardiovasc. Diabetol. PMID: 36797706
Medical Disclaimer: This article is for educational purposes only and is not intended as medical advice. Information presented is based on peer-reviewed research but should not be used for self-diagnosis. Always discuss your lab results with your healthcare provider.