Speed Converter 🚀
Free online speed converter. Convert mph to km/h, m/s to mph, knots and 25+ speed units instantly. Includes mph km/h calculator with formulas.
📐 Conversion Formula
Common Speed Conversions
Quick Speed Conversions
mph to km/h
× 1.60934
60 mph = 96.6 km/h
m/s to mph
× 2.23694
10 m/s = 22.4 mph
Knots to mph
× 1.15078
10 knots = 11.5 mph
m/s to km/h
× 3.6
25 m/s = 90 km/h
Converter Performance Metrics
How to Use Speed Converter
Step 1: Enter Speed Value
Type the speed value you want to convert in the "From" field. The converter accepts any positive number including decimals. For example, enter 60 for 60 mph or 100 for 100 km/h depending on your selected unit.
Step 2: Select Source Unit
Choose the unit of your input speed from the "From" dropdown. Options include mph, km/h, m/s, knots and 23+ other speed units. Select the unit that matches your speedometer or measurement.
Step 3: Select Target Unit
Pick the unit you want to convert to from the "To" dropdown. The conversion happens automatically in real-time as you change units. The formula used for conversion is displayed below for reference.
Step 4: Use Results
View the converted result in the "To" field. Click Copy to copy the result to clipboard, Swap to reverse conversion direction, or Reset to start over. All calculations are instant and accurate for travel and physics.
Understanding Speed Measurement
What is Speed?
Speed is the rate of change of distance with respect to time, measured in distance units per time unit. Common units: mph (miles per hour), km/h (kilometers per hour), m/s (meters per second). Speed is scalar quantity—magnitude only. Velocity is vector—includes direction. Speed = distance ÷ time.
Conversion Formulas: \( \text{km/h} = \text{mph} \times 1.60934 \), \( \text{mph} = \text{km/h} \times 0.621371 \), \( \text{m/s} = \text{km/h} \div 3.6 \), \( \text{mph} = \text{m/s} \times 2.23694 \), \( \text{knots} = \text{mph} \times 0.868976 \). Common speeds: walking ~5 km/h, running ~15 km/h, highway ~100 km/h, airplane ~900 km/h, sound ~1,235 km/h (Mach 1), light ~1,079,252,848.8 km/h.
Common Speed Units Explained
Miles per Hour (mph): Imperial/US speed unit. Distance in statute miles traveled in one hour. USA, UK road signs use mph. Highway speed limits: USA 55-75 mph, UK 60-70 mph. 1 mph = 1.60934 km/h = 0.44704 m/s. Common on speedometers in US cars. Historical standard still used despite metric system.
Kilometers per Hour (km/h): Metric speed unit used worldwide except USA, UK. Distance in kilometers traveled in one hour. Most countries use km/h for road speeds. Highway limits typically 80-130 km/h. 1 km/h = 0.621371 mph = 0.277778 m/s. Standard in Europe, Asia, Australia, most of world. More logical, based on metric system.
Meters per Second (m/s): SI unit of speed. Distance in meters traveled in one second. Used in physics, science, engineering. More natural for calculations than km/h or mph. 1 m/s = 3.6 km/h = 2.23694 mph. Sprint speeds: Usain Bolt ~10.4 m/s. Free fall: ~9.8 m/s² acceleration. Essential for scientific work and precise measurements.
Common Use Cases
🚗 Driving & Travel
Convert speed limits when traveling internationally. USA uses mph, Europe uses km/h. Understand foreign speedometers, rental cars. Calculate travel time, fuel efficiency. Essential for road trips abroad, avoiding speeding tickets, and understanding navigation apps showing different units.
🏃 Sports & Fitness
Convert running pace, cycling speed, swimming velocity. GPS watches show different units. Marathon pace ~12 km/h. Sprint ~36 km/h. Understand treadmill speeds set in mph vs km/h. Essential for training, comparing performances, and tracking fitness progress across devices.
✈️ Aviation & Marine
Convert knots (nautical miles/hour) to mph or km/h. Aircraft speeds in knots—cruise ~450 knots. Ships use knots for navigation. 1 knot = 1.852 km/h. Wind speeds in weather forecasts. Essential for pilots, sailors, and understanding aviation/maritime specifications.
🔬 Physics & Science
Convert speeds for physics problems, experiments, scientific calculations. m/s standard in physics. Calculate velocity, acceleration, momentum, kinetic energy. Speed of sound, light. Essential for homework, laboratory work, research, and understanding motion in scientific contexts.
🌪️ Weather & Wind
Convert wind speeds from weather reports. Different countries use different units—mph, km/h, m/s, knots. Hurricane categories based on mph. Beaufort scale uses knots. Understanding storm severity, sailing conditions, and outdoor activity safety requires speed conversions.
📱 Apps & Technology
Convert speeds in fitness trackers, GPS apps, navigation systems. Strava, Garmin, Apple Watch show different units. Set preferences, understand data exports, compare results. Essential for using international apps, syncing devices, and analyzing performance metrics across platforms.