Speed Converter
Convert between km/h, mph, m/s, knots, ft/s and more speed units
Unit Converter
Support fast conversion of various units including length, area, volume, weight, temperature, etc.
Common Units
Common Unit Conversions
Quick reference for frequently used unit conversions
Length
| From | To | Formula | Example |
|---|---|---|---|
| Inches (in) | Centimeters (cm) | in × 2.54 | 1 in = 2.54 cm |
| Feet (ft) | Meters (m) | ft × 0.3048 | 1 ft = 0.3048 m |
| Miles (mi) | Kilometers (km) | mi × 1.609 | 1 mi = 1.609 km |
| Meters (m) | Feet (ft) | m × 3.281 | 1 m = 3.281 ft |
| Kilometers (km) | Miles (mi) | km × 0.621 | 1 km = 0.621 mi |
Weight / Mass
| From | To | Formula | Example |
|---|---|---|---|
| Ounces (oz) | Grams (g) | oz × 28.35 | 1 oz = 28.35 g |
| Pounds (lb) | Kilograms (kg) | lb × 0.454 | 1 lb = 0.454 kg |
| Kilograms (kg) | Pounds (lb) | kg × 2.205 | 1 kg = 2.205 lb |
| Tons (t) | Tonnes (t) | t × 0.907 | 1 t = 0.907 tonnes |
Volume
| From | To | Formula | Example |
|---|---|---|---|
| Fl oz (US) | Milliliters (ml) | fl oz × 29.574 | 1 fl oz = 29.574 ml |
| Cups (US) | Milliliters (ml) | cup × 236.588 | 1 cup = 236.588 ml |
| Pints (US) | Liters (L) | pt × 0.473 | 1 pt = 0.473 L |
| Gallons (US) | Liters (L) | gal × 3.785 | 1 gal = 3.785 L |
| Liters (L) | Gallons (US) | L × 0.264 | 1 L = 0.264 gal |
Temperature
| From | To | Formula | Example |
|---|---|---|---|
| Celsius (°C) | Fahrenheit (°F) | (°C × 9/5) + 32 | 0°C = 32°F |
| Fahrenheit (°F) | Celsius (°C) | (°F - 32) × 5/9 | 32°F = 0°C |
| Celsius (°C) | Kelvin (K) | °C + 273.15 | 0°C = 273.15 K |
| Kelvin (K) | Celsius (°C) | K - 273.15 | 273.15 K = 0°C |
Area
| From | To | Formula | Example |
|---|---|---|---|
| Sq feet (ft²) | Sq meters (m²) | ft² × 0.0929 | 1 ft² = 0.0929 m² |
| Sq meters (m²) | Sq feet (ft²) | m² × 10.764 | 1 m² = 10.764 ft² |
| Acres | Hectares (ha) | acre × 0.405 | 1 acre = 0.405 ha |
| Hectares (ha) | Acres | ha × 2.471 | 1 ha = 2.471 acres |
Speed
| From | To | Formula | Example |
|---|---|---|---|
| MPH | KM/H | mph × 1.609 | 1 mph = 1.609 km/h |
| KM/H | MPH | km/h × 0.621 | 1 km/h = 0.621 mph |
| Knots | MPH | knots × 1.151 | 1 knot = 1.151 mph |
| M/S | KM/H | m/s × 3.6 | 1 m/s = 3.6 km/h |
Note: These are commonly used conversions with approximate values rounded for practical use. For precise conversions, use the calculator tool above.
Unit Conversion Reference Table
No conversion records
Your Privacy is Protected
All conversions run locally in your browser. We do not store or transmit your data.
What is Speed Conversion?
Speed conversion translates a velocity measurement from one unit to another — km/h to mph, m/s to knots, and so on. It comes up constantly in driving, running, aviation, and physics.
Speed units are distance-per-time, so they combine a length unit with a time unit. The metric system uses meters per second (m/s, the SI unit) and kilometers per hour (km/h). The imperial/US system uses miles per hour (mph) and feet per second (ft/s). Knots (nautical miles per hour) are used in aviation and maritime contexts.
A common point of confusion: speed limits in Europe are km/h, while in the US they are mph. A “100” speed limit means very different things — 100 km/h is about 62 mph, while 100 mph is dangerously fast.
How to Convert Speed Units
Speed units have conversion rates relative to a base unit (m/s):
result = value × (fromUnit rate) ÷ (toUnit rate)
Example — convert 60 mph to km/h:
60 mph = 60 × 0.44704 ÷ 0.277778 = 96.56 km/h
Key tip: For km/h ↔ mph, remember the rough factor: multiply by 1.6 (km/h→mph) or 0.6 (mph→km/h). The converter above gives exact values.
Common Speed Conversions
| From | To | Multiply by |
|---|---|---|
| km/h | mph | 0.621 |
| mph | km/h | 1.609 |
| km/h | m/s | 0.278 |
| knot | km/h | 1.852 |
| knot | mph | 1.151 |
Frequently Asked Questions
How do I convert km/h to mph?
Multiply km/h by 0.621 to get mph. For example, 100 km/h = 100 × 0.621 = 62.1 mph. To go the other way, multiply mph by 1.609. A handy approximation: 100 km/h is about 62 mph, so a 100 km/h speed limit is roughly 60 mph.
What is a knot and why is it used?
A knot is one nautical mile per hour (1.852 km/h or 1.151 mph). It is used in aviation and maritime navigation because nautical miles are based on the Earth’s coordinates. Ships and aircraft report speed in knots, while cars use km/h or mph.
How many m/s are in 1 km/h?
One km/h equals 0.2778 meters per second. To convert km/h to m/s, divide by 3.6. To convert m/s to km/h, multiply by 3.6. For example, 10 m/s = 36 km/h. Meters per second is the SI unit and is used in physics and engineering.
How fast is Mach 1?
Mach 1 is the speed of sound, which is about 343 m/s (1,235 km/h or 767 mph) at sea level and 20°C. The speed of sound changes with temperature and altitude — it is slower at high altitude where the air is colder. Mach numbers are ratios, not fixed units.
Why do runners use minutes per mile instead of mph?
Runners use pace (minutes per mile or per kilometer) because it is easier to plan a race — if you run 8-minute miles, a marathon (26.2 miles) takes about 3 hours 30 minutes. Pace is the inverse of speed: 8 min/mi equals about 7.5 mph. GPS watches display both.