Work out case fatality rate instantly with clear inputs, formula shown and shareable results.
Divides deaths by confirmed cases, the proportion of diagnosed cases that prove fatal.
Case fatality rate
CFR (%) = deaths among cases / confirmed cases x 100
Mild cases are undetected and deaths lag diagnosis, so the naive ratio is biased in both directions.
CFR uses diagnosed cases; IFR uses all infections including undetected ones and is always lower.