Below is a very interesting article about changes and variations in the British male body and how suit companies are responding. The article starts out noting how much taller and bulkier the average Briton is today from fifty years ago. This is obvious: even if you don’t think you are especially bulky, just try getting into an MG TD.
Anyone in need of a good fitting suit should consult the article:
Rule of thumb though: try to look like Prince Charles and you’ll be more than fine.