How much energy is in matter?

Einstein's equation says mass and energy are interchangeable. Drag the mass slider to see the energy equivalent if all of that mass could be converted to energy.

E = m c²

× c²

Mass m m ∝ E

1 mgpaperclip · coin · kilogram1000 kg

Energy equivalent

Try

Einstein's mass–energy equivalence, E = mc², with c = 299,792,458 m/s so that every kilogram of mass is worth 89,875,517,873,681,764 joules if converted completely. This is not a promise that an ordinary object can release all of this energy — complete conversion is a useful theoretical comparison, not something real processes achieve; nuclear fission converts only a tiny fraction of a percent of its fuel's mass, for instance.