Math
Speed, Distance and Time Calculator
Find the travel time, average speed or distance from the other two, in km/h, mph or metres per second.
Time
3 h 48 min
- In decimal hours
- 3.8 hours
380 km at 100 km/h takes 3 h 48 min, not counting stops.
How it's worked out
- Time = distance ÷ speed
380 km ÷ 100 km/h3.8 h
The formula
Speed = distance ÷ time · Distance = speed × time · Time = distance ÷ speed
Worked example
380 km at 100 km/h takes 380 ÷ 100 = 3.8 hours: 3 hours 48 minutes. Covering the same 380 km in 3 hours 30 minutes is an average of 108.6 km/h.
Questions people ask
What is the formula for speed?
Speed = distance ÷ time. Distance = speed × time, and time = distance ÷ speed.
How long does 380 km take at 100 km/h?
3.8 hours, which is 3 hours 48 minutes, before stops.
How do I turn decimal hours into minutes?
Multiply the decimal part by 60. 0.8 hours is 48 minutes.
About this calculator
Formula and rules last checked 25 October 2026Written and tested by the CalculatorDex teamReport a problem