Speed Converter
Convert between 7 speed units — meter per second, kilometer per hour, mile per hour, foot per second, knot, Mach, speed of light. Daily-driving speeds to physics-scale velocities.
What powers the Speed Converter
7 units from everyday speeds to physics-scale
1 km/h = 0.621 mph
1 knot = 1.852 km/h (nautical/aviation)
Mach 1 = 343 m/s at sea level
Speed of light reference
Simultaneous output for all units
Why the Speed Converter is different
Browser-native
The Speed Converter runs entirely in your browser. Input is processed locally — never uploaded, never logged, never cached anywhere outside your device.
No artificial limits
No daily quotas, no character ceilings, no "upgrade for more" walls. Every feature is the complete feature — the same on the first use as the thousandth.
Production-grade quality
Built to the same engineering bar as paid SaaS tools — accurate algorithms, audited logic, responsive design and accessibility-tested interactions.
Common use contexts
- Driving — kmh vs mph between countries (US uses mph, rest mostly km/h)
- Aviation — knots for airspeed
- Sailing — knot is universal for marine speed
- Physics — m/s for SI calculations
Private and secure
Zero upload
All processing happens in your browser. Input is never transmitted, logged or cached.
Works offline
Once the page loads, the tool runs without an internet connection. No network calls happen during use.
No tracking
No accounts, no cookies for tool state. Only aggregate analytics count visits at the page level.