Is the Speed Converter free?

Yes — the Speed Converter is completely free, with no account, subscription, signup, or usage limits.

Is my data uploaded or stored?

No. The Speed Converter processes everything locally in your browser. Your input is never uploaded, saved, or shared with any server.

Does the Speed Converter work offline?

Yes. Once the page has finished loading, the Speed Converter works without an internet connection.

Which browsers does the Speed Converter work in?

The Speed Converter works in all modern browsers, including Chrome, Firefox, Safari, and Edge — no plugins or extensions needed.

How fast is Mach 1 in km/h?

Mach 1 (speed of sound at sea level in dry air) ≈ 343 m/s ≈ 1,235 km/h ≈ 767 mph. You can verify this in the All Conversions table by entering 1 in the Mach field.

Speed Converter

Convert between kilometres per hour, miles per hour, knots, and m/s.

From

Metres per Second (m/s)

3.59999712

Kilometres per Hour (km/h)

1 m/s = 3.59999712 km/h

All Conversions for 1 m/s

Kilometres per Hour	km/h	3.59999712
Miles per Hour	mph	2.236936292
Feet per Second	ft/s	3.280839895
Knot	kn	1.943846172
Mach	M	0.002938669958
Speed of Light	c	3.335557e-9

Free browser-based tool · Runs 100% on your device · Last updated July 7, 2026

What is the Speed Converter?

The free Speed Converter supports 7 units: metres per second (m/s), kilometres per hour (km/h), miles per hour (mph), feet per second (ft/s), knots (kn), Mach, and the speed of light (c). Enter a speed, select source and target units, and get an instant result. The All Conversions table shows your value across all units simultaneously — from everyday driving speeds to relativistic velocities.

→ Converting km/h to mph for international driving or cycling comparisons
→ Converting knots to km/h for maritime or aviation planning
→ Converting Mach numbers to m/s for aerospace engineering
→ Converting m/s to ft/s for sports science or physics problems

How to Use the Speed Converter

1 Pick the source speed unit (e.g. km/h) from the From dropdown.
2 Enter the speed value in the input field.
3 Select the target unit (e.g. mph) from the To dropdown.
4 See the instant result in the output panel.
5 Click ⇄ Swap to reverse direction.
6 Review all units in the All Conversions table below.

Key Features

🚀
7 speed units

Covers everyday (km/h, mph), marine (knots), aerospace (Mach), and relativistic (speed of light) units.
⚓
Knots for marine and aviation

Nautical speed conversion included for maritime and flight planning use.
⚡
Instant conversion

All values update live as you type.
📊
All Conversions table

View your speed in all 7 units simultaneously.
🆓
Free, browser-based

No login, no upload — works offline after first load.

Example Usage

Example Input

From: km/h · Value: 100 · To: mph

Example Output

100 km/h = 62.1371 mph

Frequently Asked Questions about the Speed Converter

What is the Speed Converter?: The Speed Converter is a free online tool that lets you convert between kilometres per hour, miles per hour, knots, and m/s. It runs entirely in your browser, so there is nothing to install and nothing is uploaded to a server.
Is the Speed Converter free?: Yes — the Speed Converter is completely free, with no account, subscription, signup, or usage limits.
Is my data uploaded or stored?: No. The Speed Converter processes everything locally in your browser. Your input is never uploaded, saved, or shared with any server.
Does the Speed Converter work offline?: Yes. Once the page has finished loading, the Speed Converter works without an internet connection.
Which browsers does the Speed Converter work in?: The Speed Converter works in all modern browsers, including Chrome, Firefox, Safari, and Edge — no plugins or extensions needed.
How fast is Mach 1 in km/h?: Mach 1 (speed of sound at sea level in dry air) ≈ 343 m/s ≈ 1,235 km/h ≈ 767 mph. You can verify this in the All Conversions table by entering 1 in the Mach field.