Kinetic Energy Calculator
Calculate kinetic energy (KE) from mass and velocity, or find mass or velocity from a known kinetic energy value.
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How to use this calculator
KE = kinetic energy (J), m = mass (kg), v = velocity (m/s). Kinetic energy grows with the square of speed — doubling speed quadruples energy.
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Enter mass and velocity to calculate kinetic energy.
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To find an unknown value, enter the two known values and set the unknown to 0.
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Results also include momentum (p = mv) and speed in km/h.
Frequently asked questions
Why does doubling speed quadruple kinetic energy?
Because KE = ½mv², speed appears squared. Doubling v replaces v with 2v, giving (2v)² = 4v² — four times as much energy. This is why high-speed collisions are so much more destructive than low-speed ones.
What is the difference between kinetic and potential energy?
Kinetic energy is the energy of motion (½mv²). Potential energy is stored energy due to position or state (e.g., gravitational: mgh, elastic: ½kx²). The two can convert into each other — a roller coaster converts potential to kinetic energy as it descends.
How is kinetic energy related to work?
The work-energy theorem states that the net work done on an object equals its change in kinetic energy: W = ΔKE. If you apply a net force over a distance, you change the object's kinetic energy by the amount of work done.
Kinetic Energy Calculator — KE = ½mv²
Kinetic energy in everyday life
Kinetic energy determines stopping distance for vehicles (proportional to speed squared, not speed), the destructive force of a meteor impact, and the power output required to accelerate an object. A car at 100 km/h has four times the kinetic energy of the same car at 50 km/h.
Units and conversions
The SI unit of energy is the joule (J = kg·m²/s²). 1 kJ = 1,000 J. For very large energies, MJ (megajoule) or GJ are used. One food calorie (kcal) ≈ 4,184 J — a typical adult needs about 8–10 MJ of food energy per day.
Learn more from an authoritative source:
WikipediaWork & Power Calculator
Calculate work done, power output, force, distance, or time using physics formulas. W = F × d and P = W / t.
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Results are estimates for informational purposes only and do not constitute professional financial, medical, legal, or technical advice. Read full disclaimer →