Total-to-HDL Cholesterol Ratio Calculator
Divide total cholesterol by HDL to get the ratio that predicts heart risk better than total cholesterol alone, with your non-HDL figure too.
How it works
Ratio = total cholesterol ÷ HDL · Non-HDL = total − HDL · Ideal <3.5, acceptable <5, higher risk ≥5
The total-to-HDL ratio compares all the cholesterol in your blood with the protective HDL fraction that carries cholesterol back to the liver. A lower ratio means a larger share of your cholesterol is the protective kind, which predicts cardiovascular risk more reliably than total cholesterol on its own. Non-HDL cholesterol — everything except HDL — is another strong risk marker doctors increasingly favour.
Worked example
With total cholesterol of 200 mg/dL and HDL of 50 mg/dL, the ratio is 200 ÷ 50 = 4.0 : 1 — the acceptable range, aiming for below 3.5. Non-HDL cholesterol is 200 − 50 = 150 mg/dL.
Frequently asked questions
Why use a ratio instead of total cholesterol?
Two people can share the same total cholesterol but very different risk. A high HDL lowers the ratio and is protective, so the ratio captures the balance of “good” versus “bad” cholesterol that a single total number hides.
What ratio should I aim for?
Below 3.5 : 1 is considered ideal and below 5 : 1 acceptable; 5 : 1 or higher signals elevated risk. Optimal targets depend on your overall cardiovascular risk profile.
What is non-HDL cholesterol?
It is total cholesterol minus HDL, capturing all the atherogenic particles (LDL and others). Many guidelines now treat non-HDL as a primary target because it does not require fasting to measure accurately.
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Educational estimate only — not medical advice, diagnosis or treatment. Consult a qualified clinician for health decisions.