Feet per Second to Miles per Hour Converter

A mile is 5,280 feet and an hour is 3,600 seconds. So 1 ft/s is 3,600 feet per hour, and 3,600 ÷ 5,280 reduces to exactly 15/22, or 0.68182 mph. The converter uses the defined values 0.3048 m per foot and 0.44704 m/s per mph, so its results match that fraction with no rounding drift.

Multiples of 22 come out as whole numbers:

• 22 ft/s = 15 mph
• 44 ft/s = 30 mph
• 88 ft/s = 60 mph
• 1,100 ft/s = 750 mph

Feet per second is the most useful way to picture what a road speed means for stopping. Swap the units and enter an mph figure: 30 mph is 44 ft/s and 60 mph is 88 ft/s.

Multiply by your reaction time to see how far the car goes before your foot reaches the brake. With a reaction time of 1.5 seconds at 60 mph, that's 88 × 1.5 = 132 feet, all of it covered before braking starts. Braking distance is added on top and depends on the car and the road, so this converter can't give you the total.

US ammunition boxes and airgun specifications often list velocity in feet per second. A 3,000 ft/s round is moving at 2,045.45 mph. For the metric figure, choose Meters per Second in the To list: 3,000 ft/s is 914.4 m/s.

Physics problems set in US units, roller-coaster specifications and water-pipe sizing charts often use ft/s too. The converter doesn't care what is moving; it only changes the unit.

Taking two-thirds of the figure is easy but 2.22% low: 100 ft/s gives 66.7 mph against the true 68.1818. Multiplying by 0.68 cuts the error to 0.27%, giving 68. For an exact answer, divide by 22 and multiply by 15.

The reverse direction has an exact shortcut. To turn mph into ft/s, add half, then take off a thirtieth of the original: 60 mph gives 60 + 30 − 2 = 88 ft/s, with no error, because 1.5 − 1/30 is exactly 22/15.