Units To lays out speed units one to a row and amounts one to a column. Opened at cheetahs, it reads any amount of them at once in kilometres per hour, miles per hour, knots, metres per second, feet per second and every other speed unit, even garden snails, walking paces and Usain Bolts. Type an amount the way you would say it, lay out a range of amounts, and choose how many decimal places to show.