COVID-19 Mortality Risk Calculator
Estimate COVID-19 mortality risk by age, comorbidities, and vaccination status, using infection fatality rate (IFR) research published in Nature (O'Driscoll et al., 2021). Values are historical reference data covering the pre-vaccination, ancestral-strain period.
years
Main comorbidity
Vaccination status
Probability of death if infected — historical pre-immunity baseline
- 1
Base IFR for age (O'Driscoll et al.)
1.025%Interpolated from age-stratified infection fatality rate table. - 2
Apply comorbidity multiplier (×1)
1.025 × 1 = 1.025%
How does this calculator work?
COVID-19 IFR ranges from ~0.002% in young children to ~16% in the over-80s (O'Driscoll et al., Nature 2021). Multiply by comorbidity factors (diabetes ×2, CVD ×2.5) and reduce by 90% if vaccinated. These are historical pre-immunity baselines — current risk is substantially lower due to population immunity and milder variants.
Formula
How this is calculated
The infection fatality rate (IFR) measures the share of all infected individuals — including the many with mild or asymptomatic illness who are never tested — who die. This makes IFR a far more accurate gauge of biological risk than the case fatality rate (CFR), which is inflated by missed cases. Age is by far the strongest predictor: IFR roughly doubles every 5 years, rising from ~0.002% in young children to ~16% above age 80 — an 8,000-fold range across the lifespan.
This calculator applies age-stratified IFR estimates from O'Driscoll et al. (Nature, 2021), a meta-analysis covering 45 countries. A comorbidity multiplier drawn from published systematic reviews is then applied: diabetes roughly doubles the risk (×2.0), cardiovascular disease increases it by ~2.5×, obesity and hypertension add about 50% each. If fully vaccinated, a 90% reduction is applied — reflecting the early-variant vaccine efficacy against death measured in pivotal trials and early real-world data.
These figures capture a historical snapshot from 2020–2021, before Omicron, widespread population immunity, or antivirals. Current COVID-19 risk is substantially lower in most countries due to accumulated immunity and lower intrinsic variant severity. Use this tool for educational comparisons, not as a clinical decision aid.
Frequently asked questions
The case fatality rate (CFR) counts deaths among confirmed (tested) cases only. Because COVID-19 caused many asymptomatic or mild infections that went undetected, confirmed cases were a fraction of all infections, making CFR much higher than true per-person risk. The infection fatality rate (IFR) divides by all estimated infections — including undetected ones — giving a more accurate probability of death per person infected.
No — these figures are based on the ancestral/Alpha-strain period (2020–2021) before widespread vaccination or Omicron. Omicron and later variants have substantially lower intrinsic severity, and population immunity (from vaccination and prior infection) has reduced the effective IFR further. This calculator is most useful for understanding how age and comorbidities scale relative risk, or for comparing historical risk estimates.
Immune senescence — the age-related decline in immune function — combined with the accumulation of chronic conditions means older immune systems cannot control the infection as effectively. IFR roughly doubles every 5–6 years of age, a pattern seen across countries, variants, and healthcare systems. Age is the single most powerful predictor of COVID-19 mortality, larger in effect than any individual comorbidity.
TG we-Calculate Editorial Team. (2026). COVID-19 Mortality Risk Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/covid-mortality-risk-calculator
TG we-Calculate Editorial Team. "COVID-19 Mortality Risk Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/covid-mortality-risk-calculator.
TG we-Calculate Editorial Team, "COVID-19 Mortality Risk Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/covid-mortality-risk-calculator
@misc{wecalculate_covid_mortality_risk_calculator, title = {COVID-19 Mortality Risk Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/covid-mortality-risk-calculator}}, year = {2026}, note = {TG we-Calculate} }
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