Energy & Power

BTU to Joules

Convert btu to joules instantly. 1 BTU = 1055.05585262 J. Includes the exact factor, a conversion table of common values and the definition of both units.

BTU
Joules
—
One step, one exact factorBTUwhat you have× 1055.05585262Jouleswhat you getBoth units are defined against the same base unit, so the factor is exact — never an approximation.

How to convert btu to joules

To convert btu to joules, multiply by 1055.05585262. The relationship is fixed, so the same factor works for any quantity — there is nothing to look up and nothing that changes with temperature, location or context.

J = BTU × 1055.05585262

BTU to Joules conversion table

The values people look up most often, rounded for reading. Use the calculator above for anything in between.

BTUJoules
1 BTU1,055.06 J
2 BTU2,110.11 J
3 BTU3,165.17 J
5 BTU5,275.28 J
10 BTU10,550.56 J
20 BTU21,101.12 J
25 BTU26,376.4 J
50 BTU52,752.79 J
100 BTU105,505.59 J
500 BTU527,527.93 J
1,000 BTU1,055,055.85 J

What is a btu?

British thermal unit, used for heating and air-conditioning capacity.

What is a joule?

The SI unit of energy: one newton-metre, or one watt for one second.

The formula

J = BTU × 1055.05585262

Every result on this page comes from this formula. Nothing is rounded until the final display, so figures match a spreadsheet to the cent.

How to use the BTU to Joules

  1. Type the number of btu you want to convert.
  2. Read the result in joules straight away — there is no button to press.
  3. Check the table below for the values that come up most often, or reverse the conversion with the linked joules to btu page.

BTU to Joules — frequently asked questions

How many joules are in a btu?

One btu equals 1055.05585262 J. J = BTU × 1055.05585262

What is the formula to convert btu to joules?

The formula is J = BTU × 1055.05585262. It is an exact definition rather than an approximation, so the conversion never drifts no matter how large the number.

How do I convert joules back to btu?

Divide instead of multiplying: one joule is 0.0009478171 BTU. The reverse converter is linked in the related tools list.

Is this conversion exact?

Yes. Both units are defined against the same base unit by international agreement, so the factor is exact — any rounding you see is only in the display, which you can widen by entering more decimal places.

Is this btu to joules free to use?

Yes. Every calculator on the site is free, needs no sign-up, and runs entirely in your browser, so your figures never leave your device.

What people search for

This page answers each of these searches. They are the exact phrases visitors use to find the btu to joules.

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About this calculator

Written and reviewed by The Samsung Calculator editorial team. Every calculator is written against a published formula, reviewed against at least one independent reference implementation, and dated when it changes.

Last reviewed August 19, 2026 · Calculation runs client-side · No data collected · Report an error