Kinetic Energy Calculator
Calculate the kinetic energy of a moving object using its mass and velocity.
How it works
- 1Enter the object’s mass (kg or lb) and velocity (m/s or ft/s) — switch systems with the toggle.
- 2Both values are converted to SI units (kg and m/s) before KE = ½·m·v² is applied.
- 3The result is shown in joules (J), with a kilojoule (kJ) conversion below.
Use cases
- Physics students verifying homework on collisions and energy.
- Engineers estimating the impact energy of a moving component or projectile.
- Sports scientists comparing the kinetic energy of athletes or balls at different speeds.
Frequently asked questions
What is the kinetic energy formula?
Kinetic energy is KE = ½mv², where m is mass in kilograms and v is speed in m/s, giving joules. For example, a 2 kg object at 10 m/s has KE = ½ × 2 × 10² = 100 J.
Why does kinetic energy scale with the square of velocity?
Velocity appears as v² in the formula, so doubling the speed quadruples the energy. A car at 60 mph carries four times the kinetic energy it has at 30 mph — which is why higher speeds make crashes far more dangerous.
How do I convert the result to other units?
Divide joules by 1000 for kilojoules (kJ), by 3,600,000 for kilowatt-hours, or by 1055.06 for BTU. The calculator shows the kilojoule value automatically.
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