One formula covers all three
Distance = speed × time. Rearranged, speed = distance ÷ time and time = distance ÷ speed. Only the multiplication needs remembering — the other two are just moving terms across the equals sign.
Matching units is half the job
At 60 km/h for 30 minutes you travel 30 km, not 1,800 km — that number appears if the 30 minutes gets multiplied in as "30" instead of half an hour. This calculator converts everything to kilometers and hours internally, then converts the result back into m/s, mph, and pace.
km/h to m/s
Divide by 3.6: one kilometer is 1,000 meters and one hour is 3,600 seconds, so 1000/3600 = 1/3.6. 36 km/h is exactly 10 m/s. Physics problems tend to use m/s while everyday speeds use km/h, so this conversion comes up constantly.
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Frequently asked questions
QWhat is running pace and how does it relate to speed?
Pace is minutes per kilometer — the inverse of speed. A lower pace number means faster running: 12 km/h is a 5:00/km pace, 10 km/h is 6:00/km.
QWhy does my answer look 60x too big or too small?
That is almost always a minutes-vs-hours mix-up. Enter time as hours and minutes separately and let the calculator convert it — do not type "30" meaning 30 minutes into an hours field.