Whether you want to work out the average speed of a motorway journey, determine your running pace during training, or solve a physics problem – the formula v = s/t is one of the most fundamental tools in science. The speed calculator solves all three variants of the formula and handles the often tedious unit conversion between km/h and m/s at the same time.
Step by Step: How to Use the Speed Calculator
- Choose what to calculate: Do you want to find speed (v), distance (s), or time (t)?
- Set the units: Choose appropriate units – km and hours for car journeys, metres and seconds for physics problems.
- Enter the known values: Fill in the two known quantities, for example distance 340 km and time 3 h 20 min.
- Enter time correctly: For times like "3 hours 45 minutes", convert to decimal hours: 3 + 45/60 = 3.75 h – or use the calculator's built-in minutes input directly.
- Read the result and unit conversion: The calculator displays the result in the chosen unit and automatically converts to the other unit.
Practical Examples
Example 1 – Motorway journey: Munich to Hamburg: 780 km in 6 h 30 min (= 6.5 h). Average speed: v = 780 / 6.5 = 120 km/h = 33.33 m/s.
Example 2 – 10 km run: Time: 52 minutes = 0.8667 h. Average speed: 10 / 0.8667 = 11.54 km/h = 3.21 m/s. Pace: 60 / 11.54 = 5:12 min/km.
Example 3 – Calculate distance: A train travels for 2 h 15 min (= 2.25 h) at 160 km/h. Distance covered: s = 160 × 2.25 = 360 km.
Speed, Distance, Time Formulas
Formulas: v = s/t; s = v × t; t = s/v. Unit conversion: km/h × 1000/3600 = m/s. 100 km/h = 27.78 m/s. At 130 km/h motorway speed, you cover 130 km in 60 minutes.
Frequently Asked Questions (FAQ)
How do I convert km/h to m/s?
Multiply by the factor 1/3.6: 90 km/h × (1/3.6) = 25 m/s. Conversely, to go from m/s to km/h, multiply by 3.6. A handy reference: at exactly 36 km/h, the speed is 10 m/s.
What is the difference between average speed and instantaneous speed?
Average speed is total distance divided by total time – including stops. Instantaneous speed is the value at a specific moment in time, as shown on a speedometer. The calculator always computes average speeds.
How do I calculate how long a journey will take?
Formula: t = s/v. Distance 450 km, planned average speed 110 km/h: t = 450/110 = 4.09 h = 4 hours 5 minutes. For motorway trips, add 10–15% extra time for stops, traffic and fuel breaks.
