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Cholesterol Ratio Calculator

Calculate your cholesterol ratios and atherogenic risk per AHA/ESC guidelines.

If LDL is empty, it will be estimated via the Friedewald formula (only when triglycerides < 400 mg/dL).

RatioOptimalModerateElevated risk
Total/HDL< 3.53.5 – 5.0> 5.0
LDL/HDL< 2.52.5 – 3.5> 3.5
Triglyceride/HDL< 22 – 4> 4

How it works

The Total/HDL ratio is an established marker of cardiovascular risk. Per AHA/ESC, values below 3.5 are optimal, 3.5–5.0 moderate, above 5.0 elevated. The LDL/HDL ratio and atherogenic index (Triglyceride/HDL) provide additional risk insight. When LDL is missing and triglycerides < 400 mg/dL, the Friedewald formula is used: LDL = Total − HDL − Triglycerides/5.

Frequently Asked Questions

What is the cholesterol ratio and why does it matter?+
Studies (Framingham, INTERHEART) show that the Total/HDL ratio predicts heart attacks more accurately than total cholesterol alone. By accounting for protective HDL, it is a more robust single marker.
What value is optimal?+
AHA/ESC 2023: Total/HDL below 3.5 is optimal, 3.5–5.0 moderate, above 5.0 elevated risk. The LDL/HDL ratio should be below 2.5.
What is the Friedewald formula?+
The Friedewald formula estimates LDL from total cholesterol, HDL and triglycerides: LDL = Total − HDL − Triglycerides/5. It is only valid when triglycerides are below 400 mg/dL.
What does a high Triglyceride/HDL ratio mean?+
Values above 4 indicate insulin resistance and elevated metabolic risk. This ratio correlates strongly with small dense LDL particles, which are particularly atherogenic.
How can I improve my cholesterol ratio?+
Raise HDL with endurance exercise, olive oil, fatty fish, and avoiding trans fats. Lower LDL and triglycerides through weight loss, less sugar and alcohol, and a fibre-rich diet.
Do I need to fast before the blood test?+
Yes for triglycerides — and therefore for the Friedewald LDL estimate — at least 9–12 hours fasting. Total cholesterol and HDL do not strictly require fasting.

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Background

Cholesterol Ratio Explained: What Your Blood Work Really Tells You

8 min