Here is an example from the Cochrane library
> For the IHS preferred outcome of being pain free at two hours the NNT for paracetamol 1000 mg compared with placebo was 22 (95% confidence interval (CI) 15 to 40) in eight studies (5890 participants; high quality evidence), with no significant difference from placebo at one hour.
A NNT of 22 means that in absolute terms 1/22 people met the positive endpoint criteria more than placebo. This figure is usually quoted as 20% for placebo and 25% for paracetamol giving NNT of 20.
The NNT of 22 gives 1/22= 4.5%.
https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD...