Your lipid panel comes back. Total cholesterol 215, LDL 130, HDL 55, triglycerides 140. Is that good? Bad? Dangerous?
Individual cholesterol numbers are hard to interpret in isolation. That is where cholesterol ratios come in — they tell you how the numbers relate to each other, which is often more informative than any single value.
The three cholesterol ratios that matter
1. Total cholesterol / HDL ratio
The simplest and most widely used ratio.
Formula: Total Cholesterol ÷ HDL
| Ratio | Risk level |
|---|---|
| Below 3.0 | Excellent — very low risk |
| 3.0–3.5 | Ideal |
| 3.5–5.0 | Acceptable — average risk |
| Above 5.0 | Elevated risk |
| Above 6.0 | High risk |
Why it works: HDL particles remove cholesterol from arteries and transport it back to the liver (reverse cholesterol transport). A high ratio means you have lots of potentially atherogenic cholesterol relative to your protective HDL capacity.
2. LDL / HDL ratio
Focuses specifically on the balance between atherogenic (LDL) and protective (HDL) lipoproteins.
Formula: LDL ÷ HDL
| Ratio | Risk level |
|---|---|
| Below 1.5 | Excellent |
| 1.5–2.5 | Good |
| 2.5–3.5 | Borderline |
| Above 3.5 | Elevated risk |
Limitation: LDL cholesterol measures the mass of cholesterol inside LDL particles, not the number of particles. Two people can have the same LDL-C but very different particle counts — which is why ApoB is increasingly preferred over LDL-C.
3. Triglyceride / HDL ratio — the metabolic health ratio
This is the ratio that metabolic health researchers care most about. It is the best lipid-panel-based proxy for insulin resistance and small dense LDL particles.
Formula: Triglycerides ÷ HDL
| Ratio | Interpretation |
|---|---|
| Below 1.0 | Excellent — strong insulin sensitivity |
| 1.0–2.0 | Optimal |
| 2.0–3.0 | Borderline — insulin resistance may be developing |
| 3.0–3.5 | Elevated — likely insulin resistant |
| Above 3.5 | High — strong correlation with metabolic syndrome and small dense LDL |
Why this ratio is so powerful: High triglycerides and low HDL are the lipid hallmarks of insulin resistance. When triglycerides are high, the liver produces more VLDL particles, which are remodeled into small, dense LDL — the most atherogenic type. Simultaneously, HDL particles are consumed faster in this process, lowering HDL levels. The TG/HDL ratio captures this entire metabolic dysfunction in a single number.
A TG/HDL ratio above 3.5 has been shown to correlate with a preponderance of small dense LDL particles (pattern B) with approximately 80% accuracy — without needing an advanced NMR lipid panel.
Why ratios matter more than total cholesterol alone
Consider two patients:
Patient A: Total cholesterol 250, HDL 85, Triglycerides 70
- TC/HDL ratio: 2.9 (excellent)
- TG/HDL ratio: 0.8 (excellent)
- Likely very low cardiovascular risk despite "high" total cholesterol
Patient B: Total cholesterol 195, HDL 35, Triglycerides 250
- TC/HDL ratio: 5.6 (high risk)
- TG/HDL ratio: 7.1 (very high — metabolic syndrome likely)
- Likely high cardiovascular risk despite "normal" total cholesterol
Patient B would pass a basic cholesterol screening (total below 200). Patient A might be flagged for "high cholesterol." The ratios tell the real story.
Beyond ratios: ApoB and the future
Cholesterol ratios are useful, but they are still indirect measures. The field is moving toward more precise markers:
ApoB directly counts atherogenic particles. One ApoB protein sits on each LDL, VLDL, IDL, and Lp(a) particle. An ApoB below 90 mg/dL (conservative) or below 60 mg/dL (aggressive/longevity-focused) is the current gold standard for cardiovascular risk assessment.
Non-HDL cholesterol (total cholesterol minus HDL) captures all atherogenic cholesterol in a single number. It correlates well with ApoB and is already available on any standard lipid panel.
The hierarchy of predictive accuracy, from least to most precise: total cholesterol → LDL-C → non-HDL-C → ApoB. Ratios fall between LDL-C and non-HDL-C in predictive power.
How to improve your cholesterol ratios
Most interventions that improve ratios work by raising HDL, lowering triglycerides, or both:
- Exercise — aerobic exercise reliably raises HDL 5–15% and lowers triglycerides 15–30%
- Reduce refined carbohydrates and sugar — the single most effective dietary intervention for triglycerides
- Lose excess weight — particularly visceral fat, which drives triglyceride overproduction
- Omega-3 fatty acids — EPA+DHA at 2–4 g/day lowers triglycerides 25–30%
- Replace saturated fat with unsaturated fat — improves the LDL/HDL ratio
- Moderate alcohol or abstain — alcohol raises HDL slightly but also raises triglycerides; net effect depends on amount
- Increase fiber — soluble fiber (oats, beans, psyllium) binds bile acids and lowers LDL
How Merios helps
Upload your lipid panel to Merios and we automatically calculate all three cholesterol ratios alongside your individual lipid values and ApoB. Track how your ratios change over time as you modify your diet, exercise, and lifestyle. See the trajectory, not just the snapshot.
Calculate your cholesterol ratios with Merios →
This article is for informational purposes only and does not constitute medical advice. Discuss your lipid results with your physician.