COVID-19 Mortality Risk Calculator

Estimate a population-based COVID-19 mortality risk from age, sex, vaccination status, and chronic health conditions, using a published age-specific infection fatality rate curve. Educational estimate only — not a diagnosis or personalized medical prediction.

Quick Facts

Baseline formula
log10(IFR%) = -3.27 + 0.0524 × age
Levin et al., 2020 — risk of death if infected roughly doubles every 7-8 years of age.
Vaccination effect
~5-12x lower death rate when vaccinated
Based on CDC surveillance data; boosters add further reduction.
Chronic conditions
~20-40% higher relative risk per condition
Diabetes, heart or lung disease, obesity, CKD, cancer, and immunosuppression are examples (OpenSAFELY, Williamson et al., 2020).
Important note
Educational estimate only
Not a diagnosis — this does not replace advice from a physician or public health authority.

Your Results

Calculated
Baseline Age-Related Risk
-
Population-average IFR estimate for this age
Adjusted Estimated Risk
-
After sex, vaccination, and condition factors
Relative Risk Multiplier
-
Vs. an unvaccinated peer of the same age, no conditions
Risk Category
-
Illustrative banding, not a clinical score

Ready

Enter age, sex, vaccination status, and condition count, then press Calculate.

Formula and Method for COVID-19 Mortality Risk

This calculator estimates a population-level COVID-19 infection fatality rate (IFR) — the estimated probability of death if infected — starting from age, the single strongest known predictor of COVID-19 mortality, and then adjusts that baseline using published relative-risk data for sex, vaccination status, and the presence of chronic health conditions. It is built from peer-reviewed epidemiological research, not from any single patient's medical record, so treat it as an educational estimate rather than a personal prognosis.

How the calculation works

The baseline comes from the age-specific IFR curve published by Levin et al. (European Journal of Epidemiology, 2020): log10(IFR%) = -3.27 + 0.0524 × age. Because this is an exponential (log-linear) relationship, the estimated risk of death roughly doubles every 7-8 years of age. The calculator then multiplies that baseline by three adjustment factors drawn from large cohort studies: about 1.6x for male sex versus female (Williamson et al., Nature, 2020), roughly 0.20x for a completed vaccine primary series or 0.08x for primary series plus booster relative to being unvaccinated (CDC surveillance data), and about 1.3x for each major chronic condition present (diabetes, heart disease, chronic lung disease, obesity, chronic kidney disease, cancer, or immunosuppression), reflecting typical hazard ratios of roughly 1.2-1.4 per condition reported in the OpenSAFELY study of over 17 million patients. The final adjusted estimate is capped at 95% and paired with a relative-risk multiplier showing how far it sits from an unvaccinated same-age peer with no conditions.

Important limitations

  • Population averages, not personal prognosis: the formula was fit to aggregate seroprevalence and death data, mostly from 2020-2021; it cannot capture your specific medical history, treatment access, or the behavior of the currently circulating variant.
  • Simplified adjustment factors: real hazard ratios vary by condition severity, control status, and combinations of conditions — this tool uses a single representative multiplier per condition for illustration, not a precise clinical risk score.
  • Not a diagnosis: results are for general education and public-health literacy. They should never be used to make treatment decisions, and they do not replace guidance from a physician or public health authority.

Why age and vaccination dominate the result

Across nearly every published COVID-19 mortality study, age explains the largest share of variation in outcomes — older adults face substantially higher baseline risk even before any other factor is considered. Vaccination, particularly with a booster dose, has consistently been the single largest modifiable factor shown to reduce that risk, which is why it carries one of the largest multipliers in this calculator.

Frequently Asked Questions

What formula does this calculator use for baseline COVID-19 mortality risk?
The baseline is the age-specific infection fatality rate (IFR) curve published by Levin et al. (European Journal of Epidemiology, 2020): log10(IFR%) = -3.27 + 0.0524 × age. This means the estimated risk of death if infected roughly doubles every 7-8 years of age, which is the single strongest known predictor of COVID-19 mortality.
How much does vaccination reduce COVID-19 death risk?
CDC surveillance data collected during 2021-2022 found that unvaccinated adults died from COVID-19 at roughly 5 to 12 times the rate of vaccinated adults, with the largest reduction seen in people who received a booster dose. This calculator applies illustrative multipliers of about 0.20x for a completed primary series and 0.08x for primary series plus booster, relative to being unvaccinated.
Why does the calculator ask about chronic health conditions?
Large cohort studies, including the OpenSAFELY analysis of over 17 million patient records (Williamson et al., Nature, 2020), found that conditions such as diabetes, heart disease, chronic lung disease, obesity, chronic kidney disease, cancer, and immunosuppression each independently raise the relative risk of COVID-19 death, typically by roughly 20-40% per condition. This tool applies a simplified multiplier for the number of such conditions present.
Is this a personalized medical risk prediction?
No. This tool combines published population-level statistics into an educational estimate only — it cannot account for your specific medical history, the current dominant variant, treatments, or other individual factors. It is not a diagnosis, prognosis, or substitute for advice from a physician or public health professional.

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