Miles per hour to feet per second (mph to ft/s) converter

What is a mph to fps converter?

A miles per hour to feet per second converter is an online tool that changes a speed expressed in miles per hour (mph) into feet per second (ft/s), and the other way around. Both units describe how far something travels in a fixed amount of time, but they use different distance units (miles versus feet) and different time units (hours versus seconds). The converter removes the tedious arithmetic of juggling 5,280 feet per mile and 3,600 seconds per hour, giving you an instant, accurate result.

The tool is bidirectional: type a value in either field and the opposite field updates automatically. You can also switch the left input between mph and km/h, and the right input between ft/s and m/s.

How does it work?

One mile equals 5,280 feet and one hour equals 3,600 seconds. To turn miles per hour into feet per second you multiply by the number of feet in a mile and divide by the number of seconds in an hour:

$\frac{5280 \text{ ft}}{3600 \text{ s}} = 1.4\overline{6}$

So every 1 mph is exactly 1.4666667 ft/s. Going the other direction, 1 ft/s equals about 0.6818182 mph.

Formula

To convert miles per hour to feet per second:

$v_{ft/s} = v_{mph} \times 1.4666667$

To convert feet per second to miles per hour:

$v_{mph} = v_{ft/s} \times 0.6818182$

Worked examples

Example 1: 60 mph to ft/s

A car travelling at highway speed does 60 mph. In feet per second:

$60 \times 1.4666667 = 88 \text{ ft/s}$

That is why 60 mph is a common benchmark - it works out to a tidy 88 feet every second.

Example 2: 100 ft/s to mph

A projectile leaves a device at 100 ft/s. In miles per hour:

$100 \times 0.6818182 = 68.1818 \text{ mph}$

Conversion table

Notes

• The factor 1.4666667 is exact because it comes from whole-number definitions (5,280 ft per mile, 3,600 s per hour).
• Feet per second is common in ballistics, sports science, and physics problems, while miles per hour dominates road speed limits in the US and UK.
• If you work in metric units instead, the left input also accepts km/h and the right input outputs m/s, so you can mix systems freely. For the reverse tool see our ft/s to mph converter.

Frequently asked questions

How many feet per second is 1 mph?

One mile per hour equals 1.4666667 feet per second.

How do I convert ft/s to mph quickly?

Multiply the feet-per-second value by 0.6818182, or divide it by 1.4666667. For a rough mental estimate, multiply by two thirds.

Why is 60 mph equal to 88 ft/s?

Because 60 mph multiplied by the exact factor 1.4666667 gives exactly 88 ft/s. This clean number makes 60 mph a favourite teaching example.

Is the conversion factor exact or rounded?

It is exact. The value 1.4666667 shown here is simply the decimal 22/15 rounded for display; the calculator uses the full-precision ratio.