I provided the math for the U.S. based the information found on the Worldmeters site today for deaths and cases in the U.S. https://www.worldometers.info/coronavirus/ If you want the current CFR figure for the world then 1,203,164 deaths / 46,628,126 cases is 2.58% --- which pretty much matches the current U.S. calculation of CFR.
Of course.... and as noted by an entire section in Worldmeter on CFR calcualtions.... until a pandemic is over then the precise CFR with closed cases will not be known. There are methods of providing the most accurate CFR while a pandemic is ongoing -- including the reality that deaths are offset in time T several weeks from the reported cases. Worldmeter discusses some of this here - https://www.worldometers.info/coronavirus/coronavirus-death-rate/#correct Their text is below The correct formula, therefore, would appear to be: CFR = deaths at day.x / cases at day.x-{T} (where T = average time period from case confirmation to death) This would constitute a fair attempt to use values for cases and deaths belonging to the same group of patients. One issue can be that of determining whether there is enough data to estimate T with any precision, but it is certainly not T = 0 (what is implicitly used when applying the formula current deaths / current cases to determine CFR during an ongoing outbreak). Let's take, for example, the data at the end of February 8, 2020: 813 deaths (cumulative total) and 37,552 cases (cumulative total) worldwide. If we use the formula (deaths / cases) we get: 813 / 37,552 = 2.2% CFR (flawed formula). With a conservative estimate of T = 7 days as the average period from case confirmation to death, we would correct the above formula by using February 1 cumulative cases, which were 14,381, in the denominator: Feb. 8 deaths / Feb. 1 cases = 813 / 14,381 = 5.7% CFR (correct formula, and estimating T=7). T could be estimated by simply looking at the value of (current total deaths + current total recovered) and pair it with a case total in the past that has the same value. For the above formula, the matching dates would be January 26/27, providing an estimate for T of 12 to 13 days. This method of estimating T uses the same logic of the following method, and therefore will yield the same result. An alternative method, which has the advantage of not having to estimate a variable, and that is mentioned in the American Journal of Epidemiology study cited previously as a simple method that nevertheless could work reasonably well if the hazards of death and recovery at any time t measured from admission to the hospital, conditional on an event occurring at time t, are proportional, would be to use the formula:
Yes... and Worldmeter covers all of this in their detailed discussion. Since cases are normally only closes 8 weeks or more after they are reported... while in the midst of a pandemic it makes sense to use reported cases to get a more accurate and current CFR figure --- the real question is the time delay T for deaths (if used) to get a accurate numerator in the equation. Note that Worldmeter does not call this 4% figure the CFR --- it is the percentage of deaths divided by closed cases.