Calcium Score Percentile Calculator

What the CAC Percentile Calculator Shows

The coronary artery calcium (CAC) percentile compares an individual's calcium score with others of the same age and sex in population reference cohorts such as the Multi-Ethnic Study of Atherosclerosis (MESA).

While the absolute CAC score measures the amount of calcified plaque in the coronary arteries, the percentile shows how that score compares with a reference population.

For example:

• A CAC score of 120 in a 45-year-old may correspond to approximately the 90th percentile, meaning the score is higher than 90% of individuals of the same age and sex.
• The same CAC score in a 75-year-old might fall closer to the 40th percentile.

This context helps determine whether a calcium score represents early or accelerated atherosclerosis relative to peers.

Percentile estimates are derived from the Multi-Ethnic Study of Atherosclerosis (MESA), one of the largest prospective cohorts evaluating coronary calcium and cardiovascular outcomes.

Why CAC Percentiles Matter

The absolute CAC score predicts cardiovascular risk, but age-adjusted percentiles provide additional clinical context.

Younger individuals typically have very little coronary calcium. Even a modest CAC score may therefore place them in a high percentile, suggesting early development of atherosclerosis.

Conversely, older individuals often have some degree of calcification, so the same score may represent average plaque burden for age.

Clinicians therefore often consider both:

• The absolute CAC score, and
• The age- and sex-specific percentile

when interpreting results.

A CAC percentile ≥75th is generally considered evidence of higher-than-expected plaque burden for age and sex.

Interpreting CAC Percentiles

CAC percentiles are typically interpreted as follows:

• Below 25th percentile — Lower plaque burden than most individuals of the same age and sex.
• 25th–75th percentile — Average plaque burden for age.
• ≥75th percentile — Higher-than-expected plaque burden and increased lifetime cardiovascular risk.

The 2026 ACC/AHA dyslipidemia guideline recommends initiation of lipid-lowering therapy for adults with a CAC score ≥100 or ≥75th percentile, with treatment typically targeting LDL-C <70 mg/dL (1.8 mmol/L).

A CAC score of zero corresponds to the lowest percentile for age and is associated with very low short-term risk of cardiovascular events in asymptomatic individuals.

However, results should always be interpreted in the clinical context of other cardiovascular risk factors.

Relationship Between CAC Score and Cardiovascular Risk

Multiple large studies have demonstrated that CAC is a powerful predictor of cardiovascular events.

Compared with individuals with CAC = 0, those with higher CAC scores have progressively greater risk of:

• Myocardial infarction
• Coronary death
• Overall cardiovascular events

CAC scoring has been shown to improve cardiovascular risk prediction beyond traditional risk calculators, including the PREVENT equations and the Pooled Cohort Equations.

Because CAC directly measures atherosclerotic plaque burden, it provides a more individualised estimate of coronary risk.

When CAC Percentiles Are Most Helpful

CAC percentiles can be particularly informative in:

• Younger patients with detectable coronary calcium
• Individuals with family history of premature coronary disease
• Patients with borderline or intermediate PREVENT-ASCVD risk
• Situations where clinicians want to determine whether plaque burden is expected or accelerated for age

In these settings, percentiles help distinguish between age-appropriate calcification and early atherosclerosis.

For a comprehensive 10-year risk estimate incorporating CAC and traditional risk factors, use our MESA Coronary Calcium Risk Calculator. To understand when CAC scoring is indicated, see our guide to coronary artery calcium scoring.