BTU to Joules Converter

How to convert BTU to Joules

To convert BTU to Joules, multiply the value in BTU by 1,055.06. For example, 5 BTU = 5,275.3 J.

Going from BTU to Joules means applying a fixed conversion factor: one BTU (BTU) is exactly 1,055.06 Joules (J). Type any number into the converter above and the equivalent updates instantly, or use the reference table for quick lookups.

Energy conversions appear in nutrition, fitness, physics, utility bills, and engineering. The same quantity of energy can be expressed in joules, calories, kilowatt-hours, or BTU depending on the context.

Understanding BTU and Joules

The joule is the SI unit, but everyday contexts use others: food labels use kilocalories (often just called 'calories'), electricity bills use kilowatt-hours, and heating and cooling systems use BTU (British Thermal Units). One food calorie is actually a kilocalorie — 1,000 of the small physics calories — which is a frequent source of confusion.

How accurate is this conversion?

Energy conversions use standard definitions: 1 calorie = 4.184 joules, 1 kilowatt-hour = 3,600,000 joules, 1 BTU = 1,055.06 joules. These are internationally agreed values, making the conversions exact.

All conversion factors on ClearUnits are based on internationally recognised standards (the International System of Units, SI, and official definitions). Factors are reviewed for accuracy and the calculator uses full-precision values, rounding only the displayed result.

Quick reference: common BTU to Joules values

The most frequently searched conversions are 1 BTU = 1,055.06 Joules, 5 BTU = 5,275.3 Joules, 10 BTU = 10,550.6 Joules, and 100 BTU = 105,506 Joules. The full table further down covers every common value, and the calculator handles any number you need in between.