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Cholesterol Ratio

General

Total Cholesterol to HDL Ratio

Total cholesterol divided by HDL, condensing a lipid panel into a single number that's often more informative of cardiovascular risk than either value alone.

Written by · Reviewed by the thecalcu.com team · Last updated July 3, 2026

What is Cholesterol Ratio?

Cholesterol Ratio condenses two numbers from a standard lipid panel, total cholesterol and HDL, into a single figure that's often more informative than either number alone. Because total cholesterol combines both protective HDL and risk-associated LDL, a low total cholesterol reading doesn't automatically mean low risk, and a high reading doesn't automatically mean high risk, the ratio captures the balance between the two.

The Cholesterol Ratio Calculator calculates this instantly from your lipid panel values.

Formula

Cholesterol Ratio = Total Cholesterol ÷ HDL Cholesterol

Worked Example

With total cholesterol of 200 mg/dL and HDL of 50 mg/dL:

Ratio = 200 ÷ 50 = 4.0, or expressed as 4.0:1, within the generally acceptable range of below 5:1.

Key Things to Know

  • Lower is generally better: a ratio under 3.5:1 is considered optimal by many cardiologists, while above 5:1 is often flagged for further evaluation.
  • Doesn't replace individual values: check your LDL and HDL values directly alongside the ratio, not instead of them.
  • Unit-independent calculation: the ratio works the same whether your lab report uses mg/dL or mmol/L, since both values come from the same units.
  • One input among several for doctors: cholesterol ratio is a useful screening number, but it's considered alongside blood pressure, family history, and other cardiovascular risk factors.

Related Calculators

Cholesterol Ratio Calculator →Calculate your total cholesterol-to-HDL ratio, LDL/HDL ratio, and non-HDL cholesterol from a standard lipid panel, with AHA-based cardiovascular risk context.
LDL Calculator →Calculate LDL cholesterol from total cholesterol, HDL, and triglycerides using the Friedewald formula, with a risk category noted instantly.
VLDL Calculator →Estimate VLDL cholesterol from triglycerides using the Friedewald-derived formula, with a normal/borderline/high category and the 400 mg/dL caveat noted.

Related Terms

LDLLow-Density LipoproteinHDLHigh-Density LipoproteinVLDL CholesterolVery Low-Density Lipoprotein

Frequently Asked Questions

What is considered a good cholesterol ratio?

A ratio below 5:1 is generally considered acceptable, with under 3.5:1 considered optimal by many cardiologists, the lower the ratio, the more of your total cholesterol is the protective [HDL](/glossary/hdl/) type.

What two numbers do I need to calculate my cholesterol ratio?

You need your total cholesterol and your HDL cholesterol, both found on a standard lipid panel. The [Cholesterol Ratio Calculator](/cholesterol-ratio-calculator/) uses just these two values.

Is a low ratio always good, even if my total cholesterol is very high?

Not necessarily, a low ratio driven by very high HDL alongside very high total cholesterol still means your absolute [LDL](/glossary/ldl/) could be elevated, so the ratio should be considered alongside individual values, not in isolation.

Can I calculate my ratio if my lab report is in mmol/L instead of mg/dL?

Yes, the ratio itself is unit-independent since it's a division of two values in the same units, so you don't need to convert units just to calculate the ratio.

How often should I recalculate my cholesterol ratio?

Recalculate it every time you get a new lipid panel, typically every 4–6 years for healthy adults or more frequently if you have risk factors or are on cholesterol-lowering treatment.