This calculator converts a speed in miles per hour (mph) into feet per second (ft/s or fps). Type the speed in mph and you get feet per second, plus the same speed in metres per second and kilometres per hour.
Formula
One mile is exactly 5,280 feet and one hour is 3,600 seconds, so ft/s = mph × 5280 ÷ 3600 = mph × 1.46667 (exactly 22/15). For metric units, 1 mph = 0.44704 m/s exactly and 1 mph = 1.609344 km/h exactly.
- v: speed in miles per hour (mph)
- ft/s: feet per second
- m/s: metres per second; km/h: kilometres per hour
Worked Example
A speed of 40 mph.
- 40 × 5280 = 211,200 feet per hour
- 211,200 ÷ 3600 = 58.667 ft/s
- 40 × 0.44704 = 17.882 m/s
- 40 × 1.609344 = 64.374 km/h
Limits and common mistakes
- Quick mental check: ft/s is about one and a half times the mph figure (60 mph = 88 ft/s exactly).
- To go back, multiply ft/s by 0.681818 (15/22) to get mph.
- “fps” also means frames per second in video; this page is about speed only.
- The factors are exact by definition, so any rounding comes only from the decimals shown.
Formula used
in v | Speed | mph | 40 | 0 | 1000 out fps | Feet per second | ft/s | v * 5280 / 3600 | 3 out ms | Metres per second | m/s | v * 0.44704 | 3 out kmh | Kilometres per hour | km/h | v * 1.609344 | 3
Each line is one input (in, sel, list) or one result (out: label, unit, formula, decimals). How the calculators work
Method: the standard formula for this calculation, rounded as each result states. See how the calculators work or report an error.
More cards in this drawer
- M/S to Km/H Conversion Calculator and Distance36.00 km/h
- Convert Millimeters to Centimeters and Feet100.00 cm
- m/s to km/h to Feet: Speed Conversion Calculator32.81 ft/s
- Foot in Calculator Conversion: Feet to Inches and More12 in
- Feet to Meters Calculator: Convert ft to m3.048 m
- Pounds to Bushels Calculator: Convert by Commodity16.67 bu