The unit for speed is distance over time, as it is defined as the amount of time it takes an object to cover a particular distance. The base, or SI, unit is meters per second, but this is not very practical in everyday life. You are likely more familiar with units such as kilometers per hour, miles per hour, and knots. Any distance over time is a speed unit, so other units of speed include nanometres per fortnight, Boeing 787s per solar year, or bananas per Friedman. Read more