Kinetic Energy Calculator
Energy of a moving object, plus the height it would have to fall to gain the same energy.
Results
Kinetic energy
437,500.0
J
Kinetic energy
437.500
kJ
Height
31.87
m
What this tool does
Kinetic energy depends on mass once and on speed twice, which is why speed dominates the result. The equivalent fall height translates the number into something physical: the drop that would produce the same impact.
Formula
E = ½ × m × v²
Variables
| Symbol | Meaning | Unit |
|---|---|---|
m | Mass | kg |
v | Speed | km/h |
E | Kinetic energy | J |
EK | Kinetic energy | kJ |
EH | Height | m |
Worked example
- Mass1400 kg
- Speed90 km/h
- Kinetic energy437,500.0 J
- Kinetic energy437.500 kJ
- Height31.87 m
Limitations
- The formula assumes ideal conditions: no friction losses, no air resistance and no efficiency losses unless you enter them.
- Mixing units is the most common source of error. Convert every input to the units shown next to each field before calculating.
Frequently asked questions
Why does a small increase in speed matter so much?
Because energy grows with the square of the speed. Going from 50 to 70 km/h is 40 % faster but carries 96 % more energy, and all of that energy has to go somewhere in a collision. The last result shows the equivalent fall height, which is often the more intuitive way to picture it.