What this calculator does
Convert mass to rest energy with Einstein’s mass-energy equivalence.
How it works
The calculator evaluates E = mc², where c = 299,792,458 m/s. Inputs are checked before calculation, and invalid values such as zero denominators or out-of-range selections produce a clear error instead of a misleading result.
Input query strings and outputs
Use an input name in this page’s URL as ?name=value, and join additional inputs with &. Portable shared links may instead use the compact ?ac= state parameter.
Input query strings
1-
?mass=Mass (kg)Number · Required · Default: 1
Outputs
3-
energyEnergy (joules)Number · Primary output
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kilowattHoursEnergy (kWh)Number
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tntEquivalentTNT equivalent (metric tons)Number
Inputs and results
The inputs are Mass (kg). Results include Energy (joules), Energy (kWh), TNT equivalent (metric tons).