Kinetic Energy Calculator

Calculate kinetic energy, mass, or velocity using KE = ½mv²

Calculate

Choose what to calculate

Input Values

Enter known values

Mass (m) - kilograms

Mass of the moving object

Velocity (v) - m/s

Speed of the object

Common Examples

Car (1000 kg at 20 m/s)

m = 1000 kg, v = 20 m/s → KE = 200,000 J

≈ 72 km/h

Baseball (0.145 kg at 40 m/s)

m = 0.145 kg, v = 40 m/s → KE = 116 J

Fast pitch

Bullet (0.01 kg at 400 m/s)

m = 0.01 kg, v = 400 m/s → KE = 800 J

High velocity

Runner (70 kg at 8 m/s)

m = 70 kg, v = 8 m/s → KE = 2,240 J

Sprint speed

Unit Conversions

Velocity: 1 m/s = 3.6 km/h = 2.237 mph

Energy: 1 J = 0.239 cal = 0.000278 Wh

Mass: 1 kg = 1000 g = 2.205 lb

Result

Calculated kinetic energy

125

Joules (J)

= 0.13 kJ

= 29.88 calories

= 0.034750 Wh

Kinetic Energy Formula

KE = ½mv²

Kinetic Energy = ½ × Mass × Velocity²

KE = Kinetic Energy (Joules)

m = Mass (kilograms)

v = Velocity (meters per second)

Calculating: KE = ½ × 10 kg × (5 m/s)² = 125 J

Alternative Forms:

• m = 2KE / v²

• v = √(2KE / m)

Key Concepts

Energy of Motion:

Kinetic energy is the energy an object possesses due to its motion

Velocity Squared:

Doubling velocity quadruples kinetic energy (v² relationship)

Scalar Quantity:

KE is always positive and has no direction

Work-Energy Theorem:

Work done on an object equals its change in kinetic energy

About Kinetic Energy Calculator

Kinetic Energy Equation

This calculator uses the kinetic energy equation KE = ½mv², which calculates the energy an object has due to its motion. This fundamental equation in classical mechanics shows that kinetic energy is proportional to mass and the square of velocity.

Features

Calculate kinetic energy from mass and velocity
Calculate mass from kinetic energy and velocity
Calculate velocity from kinetic energy and mass
Quick velocity presets (walking, running, cycling, car)
Automatic unit conversions (J, kJ, MJ, cal, Wh)
Real-world examples from everyday objects
Velocity conversions (m/s, km/h, mph)

Understanding Kinetic Energy

Kinetic energy is one of the two main forms of mechanical energy (along with potential energy). The v² term means that velocity has a much greater effect on kinetic energy than mass - doubling the velocity quadruples the energy, while doubling the mass only doubles it. This is why high-speed collisions are so much more dangerous than low-speed ones.