In 1829 The Royal Musselburgh Golf Club invented the first known hole-cutter which had a diameter of 4.25 inches.
This particular hole-cutter is still in existence and on display at the club. It had become the accepted norm at clubs in that part of Scotland. No one knows why it exactly measures 4.25 inches
In 1891 the Royal and Ancient Golf Club of St Andrews (R&A), at the time golf's sole governing body, issued a new rule that the hole size should be standard on golf courses around the world at 4.25 inches.
Updated: 4-Nov-2022 | Email feedback to this question