It is often said that between 1% and 2%, or 70 to 140 million people around the world, have red hair. In purely numerical terms, it is highly likely that the US has the highest number of people with red hair, because of the size of its population. If just 1% had red hair, for example, that would mean it had three million redheads. According to Rees, the figure for the UK is about 10%.