Optimize
← All biomarkers
Heart & Vascular

LDL / HDL Ratio

The LDL/HDL ratio divides your 'bad' LDL cholesterol by your 'good' HDL to summarise the balance in your lipid profile.

What is LDL / HDL Ratio?

The LDL/HDL ratio divides LDL cholesterol by HDL cholesterol to give a single-number summary of the balance between atherogenic transport (LDL) and reverse transport back to the liver (HDL). A higher ratio means more atherogenic cholesterol per unit of protective cholesterol. The ratio is a derived value, not a direct measurement. The same ratio can be reached through very different routes — a strongly lowered LDL from medication tells a different story than the same ratio driven by a high HDL in someone who trains regularly. Without the absolute values and context, the full picture is missing.

Why is LDL / HDL Ratio relevant?

The ratio is useful as a quick summary when tracking changes. When LDL falls and HDL rises, the ratio improves twice as fast as the individual values would suggest — making trends more visible. Modern guidelines favour ApoB and non-HDL cholesterol as better measures of cardiovascular risk. The LDL/HDL ratio remains a readily readable indicator within a standard lipid profile. Use it as part of the broader picture, never as a standalone verdict.

LDL / HDL Ratio high or low — what it means

Always read the ratio alongside the absolute values of LDL, HDL, triglycerides, and ApoB. A low ratio driven by a low HDL — from inactivity, smoking, or high triglycerides — is not a good sign. When triglycerides are markedly elevated, ApoB is a more reliable measure of atherogenic burden. After a lifestyle change or starting medication, a retest after six to twelve weeks is appropriate — enough time for the lipid profile to respond.

LDL / HDL Ratio reference ranges

Optimal (women)Primary-prevention target, women (Millán 2009)< 2.5 ratio
Optimal (men)Primary-prevention target, men (Millán 2009)< 3.0 ratio
Increased risk (women)Increased cardiovascular risk, women (Millán 2009)> 3.0 ratio
Increased risk (men)Increased cardiovascular risk, men (Millán 2009)> 3.5 ratio

The LDL/HDL ratio is a derived, unitless measure with no official NHG cut-off. The commonly used thresholds are sex-specific (Millán et al. 2009): for women they sit roughly 0.5 lower than for men. These are guide values that vary by lab and method. Always read the ratio alongside the absolute values of LDL, HDL, triglycerides, and ApoB. Note: when triglycerides are markedly elevated (above roughly 3.4 mmol/L), the calculated LDL — and therefore the ratio — becomes unreliable.

Educational information only — not medical advice. Consult a healthcare professional for clinical decisions.

Read about our scientific approach →Read the guide: Heart health →

Frequently asked questions

What is a normal LDL/HDL ratio?

The commonly used cut-offs differ by sex. For women, a ratio below 2.5 is optimal and above 3.0 signals increased risk; for men they sit about 0.5 higher: below 3.0 optimal and above 3.5 increased risk. The lower the ratio, the more favourable the balance between plaque-forming LDL and plaque-clearing HDL. These are guide values from the literature (Millán 2009) and differ by lab.

What does a high LDL/HDL ratio mean?

A ratio above roughly 3.5 in men or 3.0 in women means there is relatively much 'bad' LDL cholesterol compared with protective HDL, which is associated with a higher risk of cardiovascular disease. It usually reflects a high LDL, a low HDL, or both. Always check the individual values and, where useful, ApoB to understand what is driving it.

Is a low LDL/HDL ratio always good?

Not necessarily. A low ratio is favourable when it comes from a low LDL and a healthy HDL. But the same low ratio can also arise from an unfavourably low HDL paired with a low LDL, or be masked by high triglycerides. When triglycerides are markedly elevated (above roughly 3.4 mmol/L) the calculated LDL becomes unreliable, and ApoB is a more reliable measure than the ratio.

When is my LDL/HDL ratio a concern?

A ratio above roughly 3.5 (men) or 3.0 (women) warrants attention, especially together with a high LDL, low HDL, high triglycerides, or other risk factors such as smoking, high blood pressure, or excess weight. The ratio is not a diagnosis; discuss an elevated result with your doctor, who will assess the full lipid profile and your personal risk.

Do I need to fast before this test?

For a reliable ratio, a fasting sample (no food for 9-12 hours) is advisable, because LDL cholesterol is usually calculated and that calculation is sensitive to recently eaten triglycerides. Follow your lab's instructions; if a result is borderline or abnormal, repeating it fasting is recommended.

Related biomarkers

LDL Cholesterol
LDL cholesterol is the cholesterol in your blood that can lodge in artery walls and build up as plaque.
HDL Cholesterol
HDL is the 'good' cholesterol that carries excess cholesterol back to your liver.
Apolipoprotein B (ApoB)
ApoB is a protein on every harmful cholesterol particle, so it counts how many of those particles circulate in your blood.
Triglycerides
Triglycerides are a blood fat that responds strongly to diet and alcohol and reflects your metabolic health.

LDL / HDL Ratio is one of the biomarkers in the Optimize blood test. Book a blood draw at any of 238+ partner labs in the Netherlands, or upload your existing results in the app.

See the full test