The boat speed in still or stagnant water can be determined by comparing the time taken to reach a distance in both upstream and downstream. Here is the speed of man in still water formula which will guide you to calculate the speed of boat with the input values of time taken to reach distance at upstream, the time taken to reach distance at downstream and stream speed. The inputs should be entered in proper units. Time taken should be in hours and speed should be in km/hr.

Where,

a = Time taken to cover distance at downstream (hours)

b = Time taken to cover distance at upstream (hours)

c = Speed of stream (km/hr)

The above speed of man in still water formula in this page should be the one among the important formulas to be remembered for competitive exams.