What Is the Average Calcium Score by Age?

Average coronary artery calcium (CAC) scores rise steadily with age, and men consistently score higher than women at every age. A large pooled analysis of more than 130,000 Western adults and 33,000 Asian adults generated percentile tables showing how scores distribute across age groups and sexes, making it possible to compare an individual’s score to population norms.¹ But comparing your number to an “average” is only one small piece of the picture, and in some ways it’s the least useful piece. What the score actually predicts, where its blind spots are, and how it changes over time matter far more.

How Calcium Scores Climb With Age

Coronary artery calcium is a marker of atherosclerosis, the buildup of plaque in the arteries feeding the heart. The scan itself measures calcified plaque using a CT scanner and produces a number called the Agatston score. A score of zero means no detectable calcified plaque. Higher scores mean more calcification.

The Multi-Ethnic Study of Atherosclerosis (MESA), one of the largest and most cited studies on this topic, confirmed that calcium amount and the proportion of people who have any calcium at all both increase steadily with age.² A 45-year-old and a 75-year-old with identical risk factors will have very different expected scores. This is why raw score alone, without age and sex context, tells you little.

Among older adults, the numbers get large. A study of people up to age 99 found median scores of 622 for men and 205 for women, reflecting decades of plaque accumulation.³ At younger ages, most people score zero. But the transition from “most people have no calcium” to “most people have some” happens gradually through the 40s and 50s, and varies by sex and ethnicity.

Why Percentiles Matter More Than Averages

If you’re 55 and your calcium score is 150, knowing that the “average” score for your age group might be somewhere around 50 or 100 is less helpful than knowing where you fall on the percentile chart. A score at the 75th percentile for your age and sex means you have more calcified plaque than three-quarters of comparable people. That ranking drives clinical decisions more than the raw number.

The pooled percentile analysis that combined data from over 134,000 Western subjects and over 33,000 Asian subjects created separate nomograms for each population, broken down by five-year age bands and sex.¹ This matters because a score of 100 in a 45-year-old man is far more alarming than a score of 100 in a 70-year-old woman. The percentile approach adjusts for the expected background of age-related calcification.

The Gender Gap

At every age, men have higher calcium scores and a higher likelihood of having any detectable calcium. In a study of healthy people aged 60 to 69, the prevalence of any meaningful calcium (score above 10) was 76% in men versus 41% in women.⁴ Women tend to develop coronary calcification roughly a decade later than men, which partly tracks with the known delay in heart disease risk that women experience before menopause.

This gap narrows with age but never fully closes. By the time people reach their 80s and 90s, most women have detectable calcium too, but men still tend to have higher scores. The clinical implication is straightforward: a given score carries different weight depending on sex, which is why every major percentile reference table is stratified by both age and sex.

Race and Ethnicity Shift the Baseline

Calcium scores vary across racial and ethnic groups in ways that aren’t fully explained by traditional risk factors like cholesterol, blood pressure, or smoking. In the MESA population of over 6,700 men and women, white participants tended to have the highest calcium burdens, while Black, Hispanic, and Chinese American participants had lower scores on average.⁵ Despite the lower baseline scores in these groups, the predictive power of calcium held: across all four groups, a doubling of the calcium score increased the risk of a major coronary event by 15 to 35%.

A study of men aged 60 to 69 found that white men had roughly double the odds of having any calcium compared to Black men, and that East Asian men also had lower odds after adjusting for standard risk factors.⁴ Interestingly, the pattern in women was different. Asian women in that study actually had higher odds of calcium compared to other groups, and the ethnic differences in women were generally less pronounced.

One thing these differences do not mean is that lower calcium equals lower risk across populations. Black Americans have higher cardiovascular mortality than white Americans despite lower average calcium scores. A study tracking calcium progression in Black and white men found that although Black men started with significantly lower scores (about 34 versus 102 on average), the rate of progression once calcium was present was essentially the same between the two groups.⁶ The separate pooled percentile tables for Western and Asian populations reflect this understanding that one size does not fit all.¹

What the Score Categories Mean

Regardless of age, calcium scores are grouped into standard risk categories that guide treatment decisions. An expert consensus document lays out the framework that most cardiologists use:

• Zero: Very low risk. Statins are generally not recommended based on the score alone.
• 1 to 99: Mildly increased risk. A moderate-intensity statin may be recommended, especially if the score is above the 75th percentile for your age and sex.
• 100 to 299: Moderately increased risk. Moderate-to-high-intensity statin therapy plus low-dose aspirin is typically suggested.
• 300 and above: Moderate-to-severely increased risk. High-intensity statin therapy and low-dose aspirin are recommended.⁷

These categories are applied regardless of age, but context still matters. A score of 50 in a 40-year-old is a much bigger deal than a score of 50 in an 80-year-old, because the younger person has accumulated plaque far earlier than expected. That’s where the percentile tables come back into play: the same raw number represents very different percentile ranks at different ages.

When Calcium Shows Up Before Age 45

Roughly one in ten young adults in the general population already has some detectable coronary calcium, and among young adults who carry traditional cardiovascular risk factors, the number jumps to about one in three.⁸ While guidelines have not formally defined “premature” calcium, there is growing agreement that any calcium in someone under 45 should be treated as a warning sign.

The consequences of early calcium are serious. In a study comparing younger and older adults, people under 45 with scores between 100 and 400 had roughly double the mortality rate of people 75 and older with zero calcium. Those under 45 with scores above 400 had a tenfold higher mortality rate than calcium-free elderly adults.⁹ In other words, a high calcium score in a young person can signal a worse outlook than being old with a clean scan.

Calcium Scoring in Older Adults

For people over 70, calcium is common enough that its absence becomes the more informative finding. A study of elderly men and women found that calcium scores still predicted survival across all age groups, and that the scan allowed doctors to reclassify risk in more than 40% of patients over 70.¹⁰ The reclassification often worked by excluding risk: a person over 70 with several risk factors but a low calcium score could be moved into a lower risk category, potentially sparing them aggressive treatment they didn’t need.

At the same time, older adults face a competing-risk problem. A calcium score predicts cardiovascular death, but the older you get, the more you’re also at risk of dying from cancer or other causes. A large consortium study found that this balance shifts with age, and that the relative predictive power of calcium for cardiovascular versus cancer mortality changes across age groups.¹¹ For an 80-year-old, knowing about heart risk is helpful, but the clinical decision about whether to start a statin also has to weigh the remaining years of potential benefit.

The Zero Score Is Not a Lifetime Guarantee

A calcium score of zero is one of the most powerful negative predictors in cardiology. It’s associated with very low event rates over the following five to ten years, and it’s the main reason many doctors use the scan as a “tiebreaker” for people whose risk based on standard factors is uncertain. A MESA analysis found that about 19% of all coronary events over a decade occurred in people who initially had a score of zero.¹² When those individuals were rescanned three to five years later, the appearance of new calcium preceded 55% of future events and identified people at roughly triple the risk.

The score also has a blind spot. It only detects calcified plaque, and some dangerous plaque is soft or “noncalcified.” A case report documented severe coronary blockage from noncalcified plaque in a patient whose calcium score was zero.¹³ A separate study of patients with zero calcium found that about 9% still had atherosclerotic plaque visible on a more detailed CT angiogram, and nearly half of those had blockages exceeding 50%.¹⁴ AI-enhanced CT angiography is beginning to reveal subclinical plaque that a standard calcium score misses entirely.¹⁵

A zero score is reassuring, not definitive. It lowers the probability of a near-term heart attack dramatically, but it doesn’t rule out the presence of early disease.

How Fast Scores Progress

Calcium scores don’t stay still. Annual progression rates of 22% to 52% have been reported in symptomatic or high-risk people, while effective lipid-lowering treatment can slow progression to 0% to 20% per year.¹⁶ In one study of asymptomatic individuals, the average annual increase in the Agatston score was about 10 points, but people who started with higher scores progressed faster.¹⁷ Rapid progression (gaining more than 10 to 20 points per year) appears to carry increased risk of future cardiac events on its own, independent of the absolute score.

This is where the biology becomes relevant. Coronary calcification isn’t just calcium drifting into artery walls. It’s an active, organized process resembling bone formation. Cells in the vessel wall undergo a transformation, taking on bone-like characteristics and producing proteins involved in mineralization.¹⁸ Smooth muscle cells in atherosclerotic plaques can shift into a state that drives calcium deposition, and this transition follows a program that mirrors what happens in bone and cartilage.¹⁹ Because calcification is a regulated biological process rather than simple mineral buildup, it responds to both the progression and the treatment of atherosclerosis.

The Statin Paradox

This is where things get genuinely confusing. Statins are the primary medication prescribed to reduce cardiovascular events, and they work. But long-term statin therapy is associated with higher calcium scores. A study found that the odds of having an elevated calcium score grew with each additional five-year block of statin use, reaching more than fourfold after ten years of treatment compared to non-users, even after adjusting for risk factors.²⁰

This doesn’t mean statins are making your arteries worse. The leading explanation is that statins stabilize vulnerable soft plaques by converting them into dense, calcified plaques that are less likely to rupture and cause a heart attack. The calcium score goes up, but the plaque becomes less dangerous. This creates a real clinical headache: if you’re on a statin and your calcium score rises, that increase likely doesn’t carry the same meaning as a rising score in someone not on treatment. Serial calcium scoring to track treatment response has clear limitations for this reason, and guidelines generally don’t recommend rescanning solely to monitor statin therapy.

How Calcium Scoring Adds to Standard Risk Tools

Standard cardiovascular risk calculators use age, cholesterol, blood pressure, smoking status, and diabetes to estimate your chance of having a heart attack or stroke. But these models miss a lot of individual variation. A systematic review and meta-analysis found that adding calcium scores to traditional risk tools improved the ability to discriminate who would and wouldn’t have an event.²¹ Among people originally classified as high risk but reclassified to low risk by their calcium score, over 91% remained event-free over five to ten years of follow-up. The calcium score is especially good at identifying people who look risky on paper but actually aren’t.

Both the older Pooled Cohort Equations and the newer AHA PREVENT calculator produce heterogeneous calcium distributions within their risk categories, meaning many people labeled “borderline” by these tools have either no calcium or quite a lot of it.²² The calcium scan essentially sorts them into meaningfully different groups that the calculators can’t distinguish on their own.

The Psychological Effect of Seeing Your Score

One underappreciated feature of calcium scoring is its motivational impact. Seeing actual images of calcium in your arteries, or getting a number that puts your plaque burden in context, changes behavior in ways that abstract risk percentages do not. In one study, statin compliance was only about 27% among people who scored zero, but climbed to nearly 59% among people with scores of 400 or higher.²³ Weight loss followed the same gradient: about 20% of people with zero scores made behavioral changes, compared to about 34% of those with the highest scores.

A separate study found that among people already prescribed statins, 91% of those with the highest baseline calcium adhered to therapy, compared to 44% of those in the lowest quartile.²⁴ In adults with type 2 diabetes, calcium scoring increased statin uptake to about 44% versus 25% with traditional risk counseling alone.²⁵ There’s an irony here: the same people at very low risk (score of zero) are also the least motivated to take preventive action, while those confronted with high scores become more committed to treatment and lifestyle changes.

The Athlete Paradox

Endurance athletes, particularly long-distance runners, present a puzzle. Despite being otherwise healthy and free of traditional risk factors, marathon and ultramarathon runners have been found to have higher rates of coronary calcification and higher average plaque burdens compared to shorter-distance runners and general population databases.²⁶ A study of 50 men who had collectively run over 3,500 marathons confirmed that elevated calcium scores are common in this group.²⁷

The explanation is still debated. Some researchers think extreme exercise promotes coronary calcification through repeated hemodynamic stress, chronic inflammation, or increased coronary artery wall shear. Others suggest the calcification in athletes may represent a more stable, benign type of plaque, similar to the statin paradox. Whatever the mechanism, it means that a calcium score in an endurance athlete can’t be interpreted the same way as a score in a sedentary person. A runner with a score of 200 and decades of high-volume training may have a very different risk profile than a couch-bound 55-year-old with the same score.

Radiation Dose and the Scan Itself

A standard calcium scoring CT scan takes about 10 to 15 minutes and doesn’t require contrast dye. The radiation dose varies depending on the equipment and protocol. One study found more than a tenfold range across different setups, from 0.8 to 10.5 millisieverts (mSv) per scan.²⁸ For reference, a chest X-ray delivers about 0.02 mSv, so even the lowest-dose calcium scan involves meaningfully more radiation than an X-ray. Newer low-voltage protocols with tin filtration have cut effective doses to roughly 0.2 mSv while maintaining excellent agreement with standard scoring, representing about a 75% dose reduction.²⁹

Beyond the Agatston Score

The Agatston score, developed in 1990, remains the standard measurement. But researchers are exploring whether splitting the score into its two components, volume and density, offers better risk prediction. A MESA analysis found that using calcium volume and density separately improved the ability to predict coronary events compared to the traditional Agatston score, with a meaningful reclassification improvement.³⁰ The counterintuitive finding: denser calcium appears to be associated with lower risk. Dense, compact calcification may signal stable, mature plaque, while diffuse, lower-density calcium may indicate more active disease.

Quantitative plaque measurements from CT angiography are also being compared to calcium scoring. Total plaque volume, which includes both calcified and noncalcified plaque, shows higher sensitivity for predicting blockages than calcium scoring alone.³¹ These tools are still largely research instruments, but they hint at a future where a single scan provides a much richer picture of plaque burden than the current scoring system allows. During calcium scoring, incidental findings like aortic or heart valve calcification can also appear, and some evidence suggests these findings carry their own mortality risk independent of the coronary score.³²