Kinetic Energy Calculator
Calculate kinetic energy from mass and velocity (KE = ½mv²)
Calculator
KE = ½mv² = 0.5 × 10 kg × (14.14 m/s)² = 999.6980 J
Energy in kJ
0.9997
Energy in cal
238.93
Velocity in km/h
50.90
Kinetic Energy Formula
- KE = ½mv² (Kinetic Energy)
- m = 2KE / v² (Mass from energy)
- v = sqrt(2KE / m) (Velocity from energy)
- 1 Joule = 1 kg×m²/s²
- 1 cal = 4.184 J
How to Use
Calculate kinetic energy from mass and velocity
Enter mass
Input the object's mass in kilograms
Enter velocity
Input the velocity in meters per second (or km/h)
Get energy
View the kinetic energy in Joules with unit conversions
Kinetic Energy
KE = (1/2) x m x v^2
Kinetic Energy equals half times mass times velocity squared.
Frequently Asked Questions
Kinetic energy is the energy an object possesses due to its motion. Calculated as KE = half x mass x velocity squared. A moving car, flowing water, or spinning wheel all have kinetic energy. The faster or heavier an object, the more kinetic energy it has.
The velocity squared term means kinetic energy increases dramatically with speed. Doubling velocity quadruples kinetic energy. A car at 60 mph has 4 times the kinetic energy of one at 30 mph. This explains why high-speed crashes are so much more dangerous.
Kinetic energy is measured in Joules (J) in SI units. One Joule equals one kg times m squared per s squared. Other common units include kilojoules (kJ = 1000 J), calories (1 cal is approximately 4.184 J), and electronvolts (1 eV is approximately 1.6x10^-19 J) for particle physics.
Kinetic energy is directly proportional to mass. Doubling the mass doubles the kinetic energy (at constant velocity). A 2000 kg truck at 30 mph has twice the kinetic energy of a 1000 kg car at the same speed.