# Energy Conversion Calculator

> Convert energy between joules, watt-hours, calories, BTU, foot-pounds, and electronvolts.

Page: https://askcalculators.com/calculator/energy-conversion-calculator/
Definition: https://askcalculators.com/calculator/energy-conversion-calculator/definition.json
JSON Schema: https://askcalculators.com/calculator/energy-conversion-calculator/schema.json
Version: 1.0.0
Maintained by: AskCalculators (software project; not a credentialed reviewer)
Qualified review: pending. Automated checks do not establish professional approval.
Page status: Live
Review status: Pending

## Use
Open the calculator page and enter values. Query-string parameters can restore and bookmark a calculation.
Example: https://askcalculators.com/calculator/energy-conversion-calculator/?value=1&fromUnit=kWh&toUnit=MJ

## Inputs
- value: Energy; type=number; required; default=1
- fromUnit: From unit; type=select; required; default=kWh; values=J|kJ|cal|kcal|Wh|kWh|BTU|ftlb|eV
- toUnit: To unit; type=select; required; default=MJ; values=J|kJ|MJ|cal|kcal|Wh|kWh|BTU|ftlb|eV

## Outputs
- result: Converted energy; format=number; primary
- joules: Equivalent joules; format=number

## Formula
joules = value × joules-per-source-unit; result = joules ÷ joules-per-target-unit

## Rules
- Empty optional inputs are undefined, not zero.
- Hidden conditional inputs are ignored.
- Do not invent missing required inputs.