What is the kinetic energy formula?

Kinetic energy is KE = ½ × m × v², where m is mass in kilograms and v is speed in metres per second. The result is in joules (J).

How do I find velocity from kinetic energy?

Rearrange the formula to v = √(2 × KE ÷ m). Select Velocity in this tool and it does the square root for you.

Is my data sent anywhere?

No. All calculations happen locally in your browser and nothing is uploaded.

What units does the calculator use?

SI units throughout — mass in kilograms (kg), velocity in metres per second (m/s) and energy in joules (J). Enter your values in these units to get a correct result.

How do I find mass from kinetic energy and velocity?

Rearrange the formula to m = 2 × KE ÷ v². Select Mass in the tool, enter the kinetic energy and velocity, and it returns the mass in kilograms.

Why does doubling speed quadruple the energy?

Because kinetic energy depends on velocity squared (v²), not velocity itself. Doubling v multiplies v² by four, so the kinetic energy becomes four times as large for the same mass.

Kinetic Energy Calculator

Kinetic energy calculator

Kinetic energy is the energy an object has because of its motion. This calculator uses the standard formula KE = ½ × m × v² and rearranges it so you can solve for kinetic energy, mass, or velocity — useful for physics homework, engineering estimates and understanding impact forces.

How it works

Choose what you want to solve for and the tool applies the matching arrangement of the formula, all in SI units (kg, m/s, J):

Kinetic energy: KE = ½ × m × v²
Mass: m = 2 × KE ÷ v²
Velocity: v = √(2 × KE ÷ m)

Enter the two known quantities and the answer appears instantly with its unit. Because energy depends on the square of speed, doubling the velocity quadruples the kinetic energy.

Example

A 2 kg ball moving at 10 m/s has kinetic energy:

KE = ½ × 2 × 10² = ½ × 2 × 100 = 100 J

If you instead know the energy (100 J) and velocity (10 m/s) and solve for mass: m = 2 × 100 ÷ 10² = 200 ÷ 100 = 2 kg, confirming the result.

All calculations happen locally in your browser — nothing is uploaded.