The paper, which has not been peer-reviewed, was published in the Lancet Infectious Diseases and funded by the UK Medical Research Council
Researchers analyzed data from 3,665 covid-19 cases in mainland China.
Researchers said the overall death rate from covid-19 is estimated at 0.66%, rising sharply to 7.8% in people aged over 80 and declining to 0.0016% in children aged 9 and under.
The estimates, calculated by researchers in the UK, used aggregate data on cases and deaths in mainland China.
Unlike other estimates, they adjusted for undiagnosed cases and the number of people in each age group of a population.
The average time between a person displaying symptoms and dying was 17.8 days.
Recovering from the disease was estimated to take slightly longer, with patients being discharged from hospital after an average of 22.6 days.
It reported that 0.04% of 10-19 year olds would probably require hospital care—as would 1.0% of people in their 20s, 3.4% of people aged 30-39, 4.3% aged 40-49, 8.2% aged 50-59, 11.8% in their 60s, 16.6% in their 70s, and 18.4% of those over 80.