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.
How to Find These Numbers on Your Lab Report
Both values come from a standard lipid panel — one of the most common blood tests.
How to Test
💡 Pro tip: Check your units: US labs typically use mg/dL, while European labs often use mmol/L. Our calculator handles both.
What is the TG/HDL Ratio?
The math is simple: take your triglyceride level and divide it by your HDL ("good") cholesterol.
Example Calculation
150
Triglycerides (mg/dL)
50
HDL (mg/dL)
3.0
A ratio of 3.0 suggests elevated cardiovascular risk and possible insulin resistance.
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.
Takes 30 seconds. No signup required.
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:
| Marker | Conversion |
|---|---|
| Triglycerides | 1 mmol/L = 88.57 mg/dL |
| HDL Cholesterol | 1 mmol/L = 38.67 mg/dL |
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:
TG/HDL Ratio Interpretation by Paradigm
Standard Medical
Research Consensus
Metabolic Optimization
Standard Medical
ESC guidelines: TG/HDL ≥3.0 indicates insulin resistance.
Many labs don't flag until > 3.5. Focus is on clinical diagnosis.
Research Consensus
Based on cardiometabolic research and MESYAS findings.
Target < 2.0 for early risk prevention. < 1.5 associated with lowest CVD risk.
Metabolic Optimization
Low-carb and ketogenic community targets for optimal metabolic health.
LMHR phenotype mean ~0.47. Well-adapted keto typically < 1.0.
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.
LDL Cholesterol vs TG/HDL Ratio
Traditional Focus: LDL
- •Single marker focus
- •Doesn't distinguish LDL particle size
- •Can be normal while metabolic issues develop
- •Primarily influenced by genetics
Emerging Focus: TG/HDL
- •Captures metabolic dysfunction
- •Strong correlation with small, dense LDL
- •Responsive to diet and lifestyle
- •Predicts cardiovascular risk independent of LDL
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.
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
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.
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 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 clear TG
Raise 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
Track Progress
Retest in 6-8 weeks
Triglycerides respond quickly
Use fasting labs
More accurate TG reading
Calculate the ratio
Don't just check individual numbers
Track trends over time
Direction matters as much as absolute value
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.
Frequently Asked Questions
Key Takeaways
- 1TG/HDL ratio is calculated by dividing triglycerides by HDL cholesterol
- 2Large studies (400,000+ participants) show it predicts heart disease — **even after accounting for LDL**
- 3High TG/HDL strongly correlates with **insulin resistance** and small, dense LDL particles
- 4Standard tests don't show it — **you need to calculate it yourself**
- 5Lifestyle changes work — cutting refined carbs and exercising can improve it **within weeks**
- 6Use mg/dL-based thresholds for consistent interpretation regardless of lab units