Speed Calculator
Calculate speed, distance, or time from any two known values. Supports km/h, mph, m/s, knots, Mach and multiple distance and time units.
Speed = Distance ÷ Time
What Is a Speed Calculator?
The speed, distance, and time relationship is expressed as: Speed = Distance ÷ Time. Given any two of the three values, you can calculate the third. This tool handles unit conversions automatically so you can mix and match km, miles, hours, minutes, and more.
How to Use
- Choose what you want to calculate: Speed, Distance, or Time
- Enter the two known values with their units
- The result and all equivalent unit conversions appear instantly
Features
- Three calculation modes: find Speed, Distance, or Time
- Speed units: km/h, mph, m/s, knots, ft/s, Mach
- Distance units: km, miles, metres, feet, nautical miles, light-years
- Time units: seconds, minutes, hours, days
- Results shown in all equivalent units simultaneously
FAQ
What is the formula used?
Speed = Distance / Time | Distance = Speed × Time | Time = Distance / Speed. All inputs are first converted to SI base units (m/s, metres, seconds) before applying the formula.
What is Mach speed?
Mach 1 is the speed of sound at sea level in dry air at 20°C — approximately 340.29 m/s or 1,225 km/h. Mach number varies with altitude and temperature; this tool uses sea-level standard conditions.
What is a knot?
A knot is 1 nautical mile per hour (1.852 km/h). It is the standard unit for maritime and aviation speeds.
Can I calculate travel time for a road trip?
Yes. Switch to Find Time, enter your distance in km or miles, and set your average speed in km/h or mph. The result will show total travel time broken down into days, hours, minutes, and seconds.