Miles per Hour to Feet per Second

Miles per hour and feet per second

A mile per hour is one international mile per hour: exactly 0.44704 m/s, or 1.609344 km/h. Speed limits and speedometers in the US and UK, and pitch speeds in baseball, use mph.

A foot per second is exactly 0.3048 meters per second. Projectile and arrow speeds, water flow and some US engineering calculations use feet per second (fps).

Worked example

Convert 60 mph: 60 × 1.466666667 = 88, so 60 miles per hour is 88 feet per second. Likewise 20 mph = 29.33333333 ft/s.

Estimating in your head

Multiply by 1.5 for a quick figure; it is off by about 2.3%. For 60 mph that gives 90 ft/s, against 88 exactly.

Going the other way

To convert feet per second to miles per hour, divide by 1.466666667 (or multiply by 0.681818181818). The swap button between the boxes opens that page.

ft/s = mph × 1.466666667

1 mph = 0.44704 m/s and 1 ft/s = 0.3048 m/s, both by definition, so the factor is their ratio: 1.466666667 (rounded here; the page uses the full value). Results drop binary floating-point noise beyond 15 significant digits and display at the precision you choose (6 significant figures by default). Copy result copies the full value.