Calculator
What the Feet per Second Converter does
Feet per Second Converter: 1 ft/s = 0.68181818 mph, so multiply a foot per second value by 0.68181818 to get mile per hour, or divide to go back. Example: 1 ft/s = 0.68181818 mph.
Supply Value, From and To and you get Result, How it was calculated and Reverse conversion back. Results refresh instantly, so trying variations costs nothing but a moment.
Having the exact factor matters more than a rough mental estimate. That is usually what brings anyone working across two measurement systems here.
This runs client-side, which means we never receive what you enter and could not retrieve it if asked.
The rest of this page documents each field, the method, and a worked example built from the values the feet per second converter loads by default.
What do the Feet per Second Converter fields mean?
The Feet per Second Converter uses 3 inputs. A complete set of starting values is loaded for you, so nothing is required before the first result appears.
| Field | What to enter | Default |
|---|---|---|
| Value | required | 1 |
| From | choose from Metre per second (m/s), Kilometre per hour (km/h), Mile per hour (mph), Foot per second (ft/s), Knot (kn) or Mach (at sea level, 15 °C) (Mach) | Foot per second (ft/s) |
| To | choose from Metre per second (m/s), Kilometre per hour (km/h), Mile per hour (mph), Foot per second (ft/s), Knot (kn) or Mach (at sea level, 15 °C) (Mach) | Mile per hour (mph) |
How does the Feet per Second Converter work?
Both units are converted through speed's base unit (m/s), so any of the 7 units in the dropdowns can be paired in either direction without loss of accuracy.
The constants come from the SI brochure and the 1959 international yard-and-pound agreement. For quantities defined empirically rather than by treaty, the current CODATA or IAU value is used instead.
Worked example
These are the values the Feet per Second Converter loads by default, and the result it produces from them. This walkthrough uses the starting values, which means you can follow along without typing anything.
| Value | 1 |
|---|---|
| From | Foot per second (ft/s) |
| To | Mile per hour (mph) |
| Result | 0.68181818 mph |
|---|---|
| How it was calculated | 1 ft/s = 0.68181818 mph, so 1 × 0.68181818 = 0.68181818 mph |
| Reverse conversion | 1.466666667 ft/s (if you meant 1 mph) |
Feet per second and mph
1 mph equals exactly 1.466… ft/s (more precisely, 1 ft/s equals exactly 0.3048 m/s, from the exact foot definition): feet per second is a US engineering and ballistics unit built on the same foot measurement as everyday US length units.
Worth knowing
- Firearm muzzle velocity is conventionally quoted in feet per second in the US (commonly ranging from several hundred ft/s for handguns to well over 3,000 ft/s for high-velocity rifle rounds), while most other countries use metres per second for the same specification.
- A quick mental shortcut: multiply mph by about 1.47 to get ft/s, useful for translating a familiar speedometer figure into the ft/s units used in some US engineering and physics problems.
- Structural and fall-safety engineering sometimes uses ft/s for terminal velocity and impact-speed calculations in US-based codes and standards, where the surrounding measurements are already in feet.
Definitions: BIPM SI Brochure · NIST reference on units
How to use it
- Put Value.
- Pick a value for From: the options are Metre per second (m/s), Kilometre per hour (km/h), Mile per hour (mph), Foot per second (ft/s), Knot (kn) or Mach (at sea level, 15 °C) (Mach).
- Pick a value for To: the options are Metre per second (m/s), Kilometre per hour (km/h), Mile per hour (mph), Foot per second (ft/s), Knot (kn) or Mach (at sea level, 15 °C) (Mach).
- The tool reacts immediately rather than waiting for you to finish the form.
- The results panel then shows Result, How it was calculated and Reverse conversion.
- Share the link rather than a screenshot. It carries the values with it.
What this tool does not do
- Repeated conversions compound rounding, so convert once from the original value where possible.
- Factors use the internationally agreed definitions; some industries round them differently.
- It cannot detect a typo that happens to fall inside the valid range.
- Read the field labels once before trusting the answer; they specify the expected unit.
Frequently asked questions
Value, From and To, nothing else. Each field is pre-filled with a sensible default, letting you treat it as a what-if tool rather than a data-entry form.
With the values loaded when the page opens, result comes out as 0.68181818 mph. Change a value and the number is recomputed on the spot.
No. Disconnect from the internet and it still works; that is the simplest proof there is no server call.
It is free to use, with no premium tier holding back the useful parts.
The logic is straightforward and testable; the worked example above uses the tool’s own defaults so you can verify it yourself.