🔄 Converters
🚀 🚀 Speed Converter: mph, km/h, Knots, m/s and Mach
Learn how to convert between speed units: mph, km/h, knots, m/s, and Mach. Covers exact conversion factors, the knot unit, Mach number, and real-world speed benchmarks.
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Speed is measured in different units depending on context: miles per hour for US road speeds, kilometers per hour for most roads worldwide, knots for maritime and aviation, meters per second for physics, and Mach for supersonic flight.
Core Conversions
- 1 mph = 1.60934 km/h = 0.44704 m/s = 0.86898 knots
- 1 km/h = 0.62137 mph = 0.27778 m/s = 0.53996 knots
- 1 knot = 1.85200 km/h = 1.15078 mph = 0.51444 m/s
- 1 m/s = 3.6 km/h = 2.23694 mph = 1.94384 knots
Conversion Table
| Convert |
Multiply by |
Example |
| mph → km/h | × 1.60934 | 60 mph = 96.6 km/h |
| km/h → mph | × 0.62137 | 100 km/h = 62.1 mph |
| m/s → km/h | × 3.6 | 10 m/s = 36 km/h |
| km/h → m/s | ÷ 3.6 | 72 km/h = 20 m/s |
| knots → km/h | × 1.852 | 30 kn = 55.6 km/h |
Knots: Why Aviation and Maritime Use Them
A knot is one nautical mile per hour. One nautical mile = 1,852 m = 1/60th of a degree of latitude, making it natural for navigation with lat/long coordinates. Speed in knots aligns directly with degrees per hour of latitude change.
Mach Number
Mach is speed as a multiple of the speed of sound, which varies with temperature:
- At sea level, 15°C: Mach 1 ≈ 340.3 m/s = 1,225 km/h = 761 mph
- At 35,000 ft cruise altitude: Mach 1 ≈ 295 m/s = 1,062 km/h
Commercial jets cruise at Mach 0.78–0.85. The Concorde cruised at Mach 2.04 (~2,180 km/h).
Speed Reference Points
| Reference |
km/h |
mph |
| Walking | 5 | 3.1 |
| 100m world record pace | 44.7 | 27.8 |
| Highway (US) | 113 | 70 |
| Commercial jet cruise | 900 | 560 |
| Speed of sound (sea level) | 1,225 | 761 |
❓ Frequently Asked Questions
How do I convert mph to km/h?▼
Multiply mph by 1.60934. Approximation: × 1.6. Examples: 60 mph ≈ 97 km/h; 70 mph ≈ 113 km/h; 100 mph ≈ 161 km/h. For km/h to mph: multiply by 0.621.
What is a knot?▼
1 knot = 1 nautical mile per hour = 1.852 km/h = 1.151 mph. Used universally in maritime and aviation because nautical miles align with latitude/longitude navigation (1 nm = 1/60th of a degree of latitude).
What is Mach 1?▼
Mach 1 is the speed of sound, which varies with temperature. At sea level (15°C): Mach 1 ≈ 340 m/s = 1,225 km/h = 761 mph. At 35,000 ft cruise altitude: Mach 1 ≈ 295 m/s = 1,062 km/h. Commercial jets fly at approximately Mach 0.80–0.85.
How do I convert m/s to km/h?▼
Multiply m/s by 3.6 (exact: 1 m/s = 3,600 m/hour = 3.6 km/h). Example: 10 m/s = 36 km/h. For km/h to m/s: divide by 3.6. Physics problems often give speed in m/s; this conversion provides everyday context.
What is the difference between speed and velocity?▼
Speed is magnitude only (60 km/h). Velocity is magnitude plus direction (60 km/h north). A car driving in a circle at constant speed has constant speed but changing velocity. Speed converters work with the scalar magnitude component.