Total cholesterol alone is only half the story. The cholesterol ratio — especially Total/HDL — predicts your risk of heart attack and stroke more accurately than absolute numbers.
This guide explains the three key ratios, the Friedewald formula, and how to improve your numbers.
The three cholesterol ratios
Total/HDL = Total cholesterol / HDL
LDL/HDL = LDL / HDL
Triglyceride/HDL = Triglycerides / HDL (atherogenic index)
Studies like Framingham and INTERHEART show these ratios are more robust markers than total cholesterol alone, because they account for protective HDL.
Target values per AHA/ESC 2023
| Ratio | Optimal | Moderate | Elevated |
|---|---|---|---|
| Total/HDL | < 3.5 | 3.5 – 5.0 | > 5.0 |
| LDL/HDL | < 2.5 | 2.5 – 3.5 | > 3.5 |
| Triglyceride/HDL | < 2 | 2 – 4 | > 4 |
Friedewald formula: LDL without direct measurement
When your lab report doesn't include directly measured LDL, you can estimate it:
LDL = Total cholesterol − HDL − (Triglycerides / 5)
Important: When triglycerides are at or above 400 mg/dL, the estimate becomes inaccurate and should not be used — LDL must be measured directly.
Triglyceride/HDL — the atherogenic index
The Triglyceride/HDL ratio is a marker for insulin resistance and metabolic syndrome. High values (> 4) correlate strongly with small dense LDL particles, which are particularly damaging — even when total LDL looks normal.
How to improve your ratio
Raise HDL
Endurance exercise (3–4×/week), olive oil, fatty fish, moderate alcohol, avoid trans fats.
Lower LDL
Soluble fiber (oats, legumes), plant sterols, less saturated fat, weight loss.
Lower triglycerides
Less sugar and alcohol, omega-3 (salmon, flaxseed), regular exercise.
Calculate your cholesterol ratio now
Total/HDL, LDL/HDL and the atherogenic index — with risk classification and Friedewald fallback. Free and no sign-up.
Calculate for free →Related calculators
Cholesterol is closely tied to weight and lifestyle. Check your BMI, your blood pressure, and your diabetes risk — three numbers that together capture cardiometabolic risk.
Conclusion
The Total/HDL ratio is a more robust risk marker than absolute cholesterol. Combined with LDL/HDL and Triglyceride/HDL, it gives a clearer picture of your cardiovascular risk. Calculate yours with our Cholesterol Ratio Calculator.
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