How many feet and inches are there in 510 millimetres?

There are 25.4 millimetres in one inch. Therefore, rounded to two decimal places, 510 millimetres is equal to 510 / 25.4 = 20.08 inches.

There are 12 inches in one foot. Therefore, 20.08 inches is equal to 20.08/12 = 1 remainder 8.08 or 1 foot 8.08 inches.