Flywheel Energy Calculator
Enter your own flywheel values to calculate ideal stored rotational energy and energy released at selected slower speeds.
A QUICK WALKTHROUGH
How to use this tool
- Enter mass, radius, and rotational speed.
- Choose solid-disc or thin-rim mass distribution.
- Add one or more final-speed fractions to compare released energy.
Formula and scope
I = ½mr² (solid disc) or mr² (thin rim); ω = 2πn/60; E = ½Iω²; kWh = E/3,600,000. For each user-entered q: final speed = qn, released energy = E(1 − q²), theoretical share = 1 − q². Ideal rotational-energy calculation only. The two shapes are simplified mass distributions. This does not assess maximum speed, rim stress, materials, structural safety, or flywheel construction.
Local processing
Values are calculated in this browser and are not uploaded.
GOOD TO KNOW
Common questions
Why do the two shapes give different results?
For the same mass and radius, the thin-rim model has twice the moment of inertia of a solid-disc model. Real mass distributions may differ from both idealizations.
What does q mean?
q is the final speed divided by the entered speed. The released-energy fraction is 1 − q² under this ideal model.
Can this determine a safe maximum speed?
No. It calculates ideal energy only and does not evaluate stress, materials, or structural safety.