Now you know a briefing of fps and mph, we can focus on the conversion. But why should we? For one of two reasons:

- You want to convert distance to speed
- You want to convert speed to distance

Here are common reasons why you'll want to convert these measurements:

### Fps to Mph

Let's say you're riding your bike and are unsure of how fast you're going. But you're able to measure your distance and estimate each second you rode your bike. This can give you a better understanding of your bike speed.

#### Example

You measured your bike speed over 30 seconds. Your Apple Watch estimates that you covered 660 feet, which means your speed was 22 feet per second (660 / 30 = 22).

Plug that into the conversion calculator and you'll know that you reached a speed of 15 miles per hour.

### Mph to Fps

Let's say you're training for a race. You're measuring your speed in miles or kilometers, but you want to optimize your performance. You're training for a 5k, which is about three miles.

After estimating an average running speed of 6.22 mph, you want to know how many feet you are covering in a second. You use the conversion calculator and get the number 9.12 fps.

For reference, top sprinter Usain Bolt can achieve speeds of 34.25 fps.