ToolBrainy

Speed Converter

Convert between km/h, mph, meters per second, knots, and more — instantly.

All conversions

Unit Value
Kilometers per hour (km/h)
Miles per hour (mph)
Meters per second (m/s)
Knots (kn)
Feet per second (ft/s)
Mach (speed of sound)

Common reference points

About This Tool

The ToolBrainy Speed Converter lets you instantly convert any speed or velocity between the most common units — kilometers per hour, miles per hour, meters per second, knots, feet per second, and Mach. Type a value, pick your units, and see both the primary result and a full conversion table update in real time.

Whether you are checking a speed limit abroad, reading a wind or boat speed in knots, working a physics problem in meters per second, or comparing aircraft speeds, everything runs directly in your browser with no data sent to a server and no account required.

How to Use

1
Enter a value

Type any number into the input field. Decimals are fully supported.

2
Select your units

Choose the unit you are converting from on the left, and the unit you want on the right. Use the swap button to quickly reverse them.

3
See all results instantly

The result updates as you type, and the table below shows conversions to every supported unit at once.

Why Use This Converter?

6 speed units

Covers everyday and technical units: km/h, mph, m/s, knots, ft/s, and Mach.

Instant results

Live conversion as you type — no calculate button, no page reload.

Swap units in one click

Hit the swap button to instantly reverse the from and to units.

Full conversion table

See your value converted to all 6 units simultaneously in one clean table.

Reference presets

One-click presets for common speeds: walking, cycling, highway, sprinting, and more.

Private and free

Runs entirely in your browser. Nothing is sent to a server. Always free.

Use Cases

Driving abroad

Convert km/h speed limits to mph (or the reverse) when driving in a country that uses different units.

Boating and sailing

Convert knots to km/h or mph to understand boat and wind speeds reported in nautical units.

Physics and engineering

Convert speeds to meters per second for calculations, homework, and lab measurements.

Aviation

Compare aircraft cruise speeds in knots, km/h, mph, and Mach when reading flight data.

Sports and fitness

Convert running, cycling, or sprint pace between km/h, mph, and m/s to track performance.

Weather

Convert wind speed between knots, km/h, and mph when reading forecasts and marine reports.

Frequently Asked Questions

How do I convert km/h to mph?

To convert kilometers per hour to miles per hour, multiply by 0.621371. For example, 100 km/h equals about 62.14 mph. This tool does the calculation automatically to full precision as you type.

What is a knot?

A knot is one nautical mile per hour, equal to exactly 1.852 km/h or about 1.15078 mph. Knots are used in maritime and aviation contexts for boat, wind, and aircraft speeds.

How do I convert km/h to m/s?

To convert kilometers per hour to meters per second, divide by 3.6. For example, 36 km/h equals 10 m/s. Meters per second is the SI unit for speed used in physics.

What is Mach 1?

Mach 1 is the speed of sound, approximately 1,234.8 km/h (about 767 mph) at sea level in standard conditions. The exact value changes with air temperature and altitude; this tool uses the sea-level standard.

Is this speed converter accurate?

Yes. This tool uses standard defined conversion factors — for example, 1 mph is exactly 1.609344 km/h and 1 knot is exactly 1.852 km/h. All conversions chain through meters per second as the base unit, ensuring maximum precision.

Can I convert very high or very low speeds?

Yes. The tool handles any numeric value including very high speeds (like aircraft in Mach) and very low ones (like a slow walk). Results are formatted to avoid unnecessary trailing zeros.

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