General Discussion
In reply to the discussion: The UK currently has 1,657,270 positive cases of COVID-19 [View all]muriel_volestrangler
(105,933 posts)As many have pointed out, a large number (in fact, most) of the tests are not 'random', so your calculations in the OP do not produce a meaningful figure. However, the Office for National Statistics does use its expertise and knowledge of how the tests are done to produce a proper figure. The latest result is here:
https://www.ons.gov.uk/peoplepopulationandcommunity/healthandsocialcare/conditionsanddiseases/bulletins/coronaviruscovid19infectionsurveypilot/2july2021
There is also a study that does sample people in England truly at random - 'REACT' (I took part in this a few months ago, and didn't have covid). This reports every month, and its last one was for samples taken from 20th May to 7th June.
https://www.imperial.ac.uk/news/224113/coronavirus-infections-rising-exponentially-england-react/
The rate for England then was 1 in 670; that's about 85,000, and might be 100,000 for the whole of the UK. The ONS figures are for up to 26th June. New cases went from about 5,000 to 12,000 from 7th to 26th June, so the increase from 100,000 to 257,000 in the same time looks about right. The latest new cases figure is 25,000, and if that rate of growth applied to the total, then about 535,000 in the UK have covid at the moment.