Converting Feet per Second to Miles per Hour (ft/s to mph) is a classic calculation in physics and engineering. While scientists often measure velocity in feet per second (e.g., measuring the speed of a baseball pitch or a projectile), the general public understands speed in miles per hour. The “magic number” to remember is 88: traveling at 60 mph is exactly equal to 88 ft/s.
Master Speed Converter
The Formula
Multiply the Feet per Second by 0.6818:
ft/s × 0.6818 = mph
Example
If a baseball pitch travels at 100 ft/s:
100 × 0.6818 = 68.18 mph
Ballistics & Athletics Speed Insights
A mile is much longer than a foot (5,280 times longer!), but an hour is also much longer than a second (3,600 times longer). When you combine these, you find that 1 foot per second is about two-thirds of a mile per hour.
Frequently Asked Questions
In sports like baseball or track and field, events happen in fractions of a second. Measuring a baseball pitch in feet per second allows coaches to see how much ground the ball covers in the blink of an eye, whereas MPH is better for understanding the overall “speeding ticket” velocity.
For a quick estimate, take your feet per second value and multiply it by 0.7 (or subtract about 30%). For example, if a car is moving at 100 ft/s, 100 minus 30% is 70. The real answer is 68.18 mph, so this mental trick gets you very close!
While often used interchangeably, “speed” is just how fast you are going (like 60 mph), while “velocity” includes the direction (like 60 mph North). Most everyday conversions from feet per second to mph are dealing strictly with speed.