Speed distance time calculator
Find speed, distance or time from the other two.
Fill in the fields and the result will appear here automatically.
Finds speed, distance or time from the other two quantities in km, hours and km/h. Speed is distance divided by the chosen elapsed time; include stops in that time if you want the average to include them. Motion second by second and changes in speed are not modelled. The hours-and-minutes row rounds to the nearest minute, while the primary time result retains a more detailed value.
How it works
Formula and logic
Speed = distance ÷ time, distance = speed × time, time = distance ÷ speed. Each mode shows only its two known inputs. Quantities are nonnegative; a time or speed used as divisor must be positive. Zero distance gives zero speed or time with a positive divisor; 0/0 is unsupported. The interface does not switch automatically to miles or seconds.
Example
420 km covered in 5 hours is an average of 84 km/h.
Fields and units
- What to find — list option
- Distance, km — km
- Time, hours — h
- Speed, km/h — km/h
How to use
- — Choose which value you need.
- — Enter the two you know.
- — Read the result and the journey time.
Method and limitations
- Calculation method
- Formula and logic
- Data or methodology source
- OpenStax §2.5: displacement, average velocity and stopping at constant deceleration
- Limitation
- Quantities are nonnegative; a time or speed used as divisor must be positive. Zero distance gives zero speed or time with a positive divisor; 0/0 is unsupported.
FAQ
Is this average or instantaneous speed?
Average. It answers how fast you travelled overall, including whatever the traffic did along the way.
Should I include stops in the time?
That is your choice, and it changes the meaning. Including them gives the average for the whole journey; excluding them gives the average while moving.
Can I use miles?
Not directly — the calculation works in kilometres. Convert first with the unit converter if your figures are in miles.
Why is zero speed rejected when finding time?
Dividing by it has no value: standing still, no distance is ever covered, so no time answers the question.