CALCULATE WITH CONFIDENCE

Unit Conversions · Engineering & science

Energy Converter

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

Unit Conversions · Engineering & science

Convert energy

Private in-browser conversion · common equivalents included
Energy Converter — visual relationshipUses the current inputs
Energy Converter— J—known quantity → unit-aware physical relation → result
The visual explains this calculator’s quantity and updates from the entered values. It does not add measurement accuracy or infer missing physical data.
  1. 1EnterProvide the known values
  2. 2CalculateResults update automatically
  3. 3VerifyReview the details and units
Try an example

Enter one finite number. Signed values are accepted when they represent direction, change, gauge convention, or transfer direction. Select explicitly labeled units—especially where US, Imperial, decimal, or binary conventions differ. Results stay in this browser.

Conversion result

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Enter valid values to see the result.

Your entries are calculated in this browser and are not submitted to 365CALCS.COM.

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Understand the engineering model

What is Energy?

Engineering units name the same physical quantity under different standards. Signed quantities can retain direction or transfer convention; nonnegative material properties remain magnitudes.

This converter expresses the same energy under another stated engineering unit.

The relationship

Write the model before substituting values

See the calculation

From measurement to engineering result

Worked context

Read the output with its units

One kilowatt-hour equals exactly 3.6 megajoules.

Interpret with care

Important model boundary

Calories are thermochemical calories and BTU are International Table BTU; food Calories are kilocalories.

A calculated value does not certify a component, material, installation, operating envelope, code requirement, or safety decision. Check measurements, signs, standards, uncertainty, and professional approval where consequences matter.

Browse Engineering & science for connected physical relationships.

Quick guide

How to use this calculator

  1. Enter the value exactly as recorded, then choose its source unit and the unit you need.
  2. Check regional and technical qualifiers in the unit names. US and Imperial gallons, force and mass, absolute temperatures and temperature differences, and decimal and binary data prefixes are deliberately separate.
  3. Use the selected result first, then open the common-equivalents table when you need to compare several standards without re-entering the value.

Calculation method

How the energy converter works

The entered energy is converted once to the canonical joule basis and then from that basis to the selected output unit.

Calories are thermochemical calories and BTU are International Table BTU; food Calories are kilocalories.

Worked example

Energy example

One kilowatt-hour equals exactly 3.6 megajoules.

source value × source-to-joule relationship → canonical joule value → destination-unit relationship

Supported inputs

Precision and limits

Unit convention

Calories are thermochemical calories and BTU are International Table BTU; food Calories are kilocalories.

Precision

Definitions and exact conventional factors are retained internally where available. Display formatting uses up to 12 significant digits; very large or small results use scientific notation. Do not treat displayed digits as measurement accuracy beyond the source value.

Quantity boundary

This page converts energy. It does not infer a different physical quantity, material property, environmental condition, exchange rate, calendar rule, or regulatory value needed to make a cross-quantity conversion.

Privacy

Entered values and converted results stay in this browser and are not sent to analytics or third parties.

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