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What is a Speed Converter?
A speed converter switches a velocity value between kilometres per hour, miles per hour, metres per second, and knots. India's road signs and vehicle speedometers use km/h, US and UK speedometers use mph, physics problems use m/s as the SI unit, and aviation or marine navigation uses knots. This tool helps drivers compare an imported car's mph-rated top speed with Indian km/h limits, students converting a physics problem's m/s answer into a more intuitive km/h figure, and travellers making sense of a US rental car's mph speedometer.
Conversion Formula
Every unit is converted to km/h first (the base unit here), then divided by the target unit's km/h-equivalent:
Result = value in km/h ÷ (target unit factor)
Common Conversion Factors
| Unit | Equal to (km/h) |
|---|---|
| Kilometre/hour (km/h) | 1 km/h (base unit) |
| Mile/hour (mph) | 1.60934 km/h |
| Metre/second (m/s) | 3.6 km/h |
| Knot | 1.852 km/h |
Worked Example
India's typical national highway speed limit is 100 km/h for cars — what is that in mph, as an imported speedometer might show it?
Or take a sprinter's peak speed of roughly 10 m/s: 10 × 3.6 = 36 km/h, showing how quickly a small per-second figure scales up once converted to an hourly rate.
How to Use This Calculator
- Enter the speed value you want to convert.
- Select the unit you're converting from.
- Select the unit you're converting to.
- Click Calculate to see the instant result.
Planning a road trip? Combine this with the Fuel Cost Calculator or Trip Cost Calculator to estimate journey time and cost together.
📅 Last reviewed: July 2026 · Formulas verified against RBI/SEBI/IT Dept guidelines.