What is the average height of a person worldwide?

For adults born in 1996, NCD-RisC estimates a world average of about 171 cm for men and 159 cm for women, so roughly 165 cm for both sexes combined. Dutch men are the tallest at 182.5 cm. Men are about 12 cm taller than women in every country. Average height rose by 5 to 20 cm over the 20th century, depending on the country.

Source: NCD Risk Factor Collaboration (2016), eLife