Speed Conversion Calculator
Convert between different speed units including mph, km/h, m/s, knots, and more
Speed Unit Converter
Miles per Hour
Kilometers per Hour
Common Speed Examples
Highway Speed Limit
70 mph = 112.7 km/h
70 mph = 31.3 m/s
Running Pace
6 mph = 9.7 km/h
6 mph = 2.7 m/s
Commercial Aircraft
500 mph = 804.7 km/h
500 mph = 434 knots
Key Conversion Factors
Speed Unit Categories
Imperial/US
mph, ft/s, yd/s
Common in US, UK
Metric
km/h, m/s, cm/s
International standard
Nautical
knots
Maritime and aviation
Common Applications
Vehicle speed limits and performance
Running and athletics training
Aviation and flight planning
Marine navigation
Scientific and engineering calculations
Understanding Speed Conversion
What is Speed?
Speed is the rate at which an object covers distance. It's a scalar quantity that describes how fast something is moving, without considering the direction of movement. Speed is calculated as distance divided by time.
Speed vs Velocity
- •Speed: How fast (scalar quantity)
- •Velocity: How fast + direction (vector quantity)
- •Speed is always positive or zero
- •Velocity can be positive or negative
Common Speed Units
Everyday Use
- • mph: Cars, speed limits (US/UK)
- • km/h: Cars, speed limits (worldwide)
- • knots: Ships, aircraft
Scientific Use
- • m/s: Physics, engineering
- • ft/s: Engineering (US)
- • km/s: Astronomy, space
Conversion Formula
Speed₂ = Speed₁ × Conversion Factor
All conversions use meters per second (m/s) as the base unit
Example: 60 mph to km/h
1. Convert mph to m/s: 60 × 0.44704 = 26.82 m/s
2. Convert m/s to km/h: 26.82 × 3.6 = 96.55 km/h
Result: 60 mph = 96.6 km/h
Practical Applications
Transportation
Converting speed limits when traveling between countries, calculating fuel efficiency, trip planning.
Sports & Fitness
Track and field records, running pace calculations, cycling performance metrics.
Engineering
Fluid dynamics, mechanical systems design, safety calculations, material testing.