How do You Calculate Average Speed?

The formula of speed is Distance divided by time. To calculate an average speed for 2 different speeds to the same distance. we can use the simple formula of total average speed=total distance divided by total time = 2D/(t1+t2), where D is the distance traveled and t1 and t2 are the time taken to reach the distance (t1 and t2 can be calculated using the basic formula of speed which S1 =D/t1 => t1=D/S1, likewise for t2=D/S2). Still the average speed can be derived to make it simpler, Average speed = 2D / (t1+t2)=2D / (D/S1+D/S2) = 2S1*S2 / (S1+S2). For example, if a van travels at 50 kmph on a 40 km distance and at 65 kmph on return, we can calculate the average speed on the entire trip by using the formula, 2S1*S2 / (S1+S2) = 2*50*65/ (50+65) =2*50*65 / 115 = 56.52 kmph, which is the average speed.You can find more information here: