Ballistic Energy Calculator
Ballistic energy calculator works out Kinetic energy and Rotational kinetic energy from Mass, Speed and Height. The default figures on this page give kinetic energy of 9 J; change any entry and the result, the working and the sources update together.
Your figures
Updates as you typeHow this is worked out
1 step
- Kinetic energy = m v^2 / 2 = 2 x 3^2 / 2 = 9 J
Its 5 worked examples are re-run on every release, last on 15 September 2026. What changed
Sources and references
3 sources
What the ballistic energy calculator calculates
Computes translational kinetic energy, rotational kinetic energy, gravitational potential energy, work and power.
How to use this ballistic energy calculator
Enter Mass, Speed, Height and Moment of inertia. Kinetic energy updates as you type, and “Use a worked example” loads checked figures you can adjust. Change one figure at a time to see what drives the result.
How the result is worked out
Open “How this is worked out” beside the result for the step-by-step calculation behind Kinetic energy, Rotational kinetic energy and Gravitational potential energy.
The method follows Newtonian mechanics: v = dx/dt, F = ma, J = F dt = dp, and the work-energy relations, BIPM, The International System of Units (SI Brochure) and Kinetic energy E = mv^2/2; rotational kinetic energy E = I omega^2/2; gravitational potential energy E = mgh.
Research R3750-GT-1: 2 kg at 3 m/s example
With Mass: 2, Speed: 3, the calculator returns Kinetic energy: 9. This example is checked against an independent source in the test suite.
What you can compare
Change one input at a time to see how it affects Kinetic energy, Rotational kinetic energy and Gravitational potential energy. The inputs you can vary are Mass, Speed, Height, Moment of inertia, Angular speed and Force.
Results are general information, not financial, tax, legal, medical or engineering advice. Check any decision that matters with a qualified professional.
See something wrong? Report a problem with this calculator
Frequently asked questions
Is there a free ballistic calculator available?
The calculation is free and does not require an account. An account is only needed for optional features such as saving, comparing, exporting, or sharing supported scenarios.
How many joules is a 9mm bullet?
On the figures this page opens with — mass 2 kg and speed 3 m/s — the kinetic energy is 9 J. No single number fits everyone: change any figure above and the answer updates as you type, with each step of the arithmetic beside it.
What is the formula for ballistic energy?
It needs Mass, Speed, Height, Moment of inertia, Angular speed and Force. Nothing else is required, and the figures stay in your browser.
How much does a bullet drop from 100 to 200 yards?
The result gives Kinetic energy, Rotational kinetic energy, Gravitational potential energy, Work done, Power and Total mechanical energy, each labelled with its unit so the figure can be read on its own.
What information do I need for the ballistic energy calculator?
You need Mass, Speed, Height, Moment of inertia, Angular speed, Force, Distance moved and Time. The page opens with default figures that give kinetic energy of 9 J, so you can see the scale before entering your own.
What does this ballistic energy calculator show?
It shows Kinetic energy, Rotational kinetic energy, Gravitational potential energy, Work done, Power, Total mechanical energy and Energy, with the working and any warnings for your entries.