Speed measures how fast distance is covered per unit of time. The SI unit is meters per second (m/s), but everyday life uses km/h or mph, aviation uses knots and Mach, and physics uses m/s or fractions of the speed of light.
Speed Converter is a free browser tool from SimpleCounter. Free speed converter. Convert km/h, mph, m/s, knots, ft/s, Mach instantly. Formulas, reference table, and FAQs included. Enter your values and the result updates as you type — there is nothing to install and no account to create.
Definition: Speed Converter
A speed converter takes the numbers you enter and returns the result using the standard formula for that calculation, so you do not have to work it out by hand.
Key facts
Key facts about Speed Converter
Cost
Free, with no account and no usage limit.
Where the maths happens
In your browser. The values you type are not sent to a server.
Devices
Any modern browser on phone, tablet, laptop or desktop.
Accuracy
Standard published formulas, shown with the units you selected.
Intended use
Estimates for everyday and educational use, not professional advice.
How to use the speed converter
Type your value into the first field.
Choose the unit or option that matches your figures, if the tool offers a choice.
Read the result — it recalculates immediately, with no submit button.
Change any input to compare a second scenario side by side.
Disclaimer: This tool is provided for educational and informational purposes only. Results are estimates based on standard formulas and the inputs you provide. For financial, medical, legal, or tax decisions, consult a qualified professional. See our full disclaimer.
Frequently Asked Questions
How do you convert km/h to mph?
Multiply km/h by 0.621371. Example: 100 km/h × 0.621371 ≈ 62.14 mph. To convert mph to km/h, multiply by 1.60934.
How do you convert m/s to km/h?
Multiply m/s by 3.6. Example: 10 m/s × 3.6 = 36 km/h. The factor comes from 3,600 seconds per hour divided by 1,000 meters per km.
What is a knot?
1 knot = 1 nautical mile per hour ≈ 1.852 km/h ≈ 1.15078 mph. Used in aviation and maritime navigation because nautical miles align with latitude.
What is Mach speed?
Mach 1 is the speed of sound, approximately 343 m/s, 1,235 km/h, or 767 mph at sea level in dry air at 20°C. Mach 2 is twice that speed. The actual value varies with temperature and altitude.
How fast is 60 mph in km/h?
60 mph ≈ 96.56 km/h. This is a common speed limit in the US and a reference point for car acceleration tests (0–60 mph).
What's a typical commercial airliner cruising speed?
Around 900 km/h, 560 mph, 485 knots, or roughly Mach 0.78–0.85 at cruise altitude.
How fast is the speed of light?
Approximately 299,792,458 m/s, or about 1.08 billion km/h. It's the universal speed limit in physics, denoted c.
Benefits of using the Speed Converter
What you actually get compared with a mechanical clicker, a notes app, or trying to hold the number in your head.
Nothing to install, nothing to sign up for
Open the speed converter and start counting in the same second. No account, no email, no trial.
Your count survives real life
Totals are saved on your device as you go, so a locked screen, a closed tab, or a lost signal does not reset anything.
Works offline once loaded
Install it to your home screen and it keeps working in a warehouse, a pool hall, a field, or a plane — no connection needed.
Private by default
Counts stay in your browser. There is no cloud sync, no profile, and nothing about what you count is sent to us.
Free, with no sign-up
Works offline once loaded
Counts stay on your device
Installable as an app
Runs in your browser — nothing to download
72+ counter types available
Share your setup
We publish only real, attributed feedback here — so this space is intentionally empty until we have your words to put in it. Tell us what you use the speed converter for and we will add your story, with your name, to this page.