A attojoule (aJ) is a metric-prefixed unit of energy equal to 10-18 joules, a fraction of a single joule, using the SI atto prefix.
Attojoules to Btu
Convert Attojoule (aJ) to British thermal unit (BTU) instantly with an exact formula, conversion table, and FAQ.
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Convert attojoules (aJ) to btu (BTU) instantly with formula, conversion table, and FAQ.
Context values
Some unit families need one extra value for a physically accurate result.
The British thermal unit (BTU) is the energy needed to raise one pound of water by one degree Fahrenheit, widely used for heating and air-conditioning ratings.
BTU = aJ × 9.478171203e-22
Results update instantly for Attojoules to Btu conversions.
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Formula
BTU = aJ × 9.478171203e-22
aJ = BTU × 1.055055853e+21
Conversion table
| 1 aJ | 9.478171e-22 BTU |
| 5 aJ | 4.739086e-21 BTU |
| 10 aJ | 9.478171e-21 BTU |
| 20 aJ | 1.895634e-20 BTU |
| 50 aJ | 4.739086e-20 BTU |
| 100 aJ | 9.478171e-20 BTU |
| 500 aJ | 4.739086e-19 BTU |
| 1000 aJ | 9.478171e-19 BTU |
Related conversions
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How the formula works
Both attojoule and british thermal unit measure the same physical quantity, so converting between them is a single multiplication. Multiply a value in attojoules by 9.478171203e-22 to get btu. To reverse the conversion, multiply a british thermal unit value by 1.055055853e+21 to get back to attojoules.
Frequently asked questions
What is Attojoule (aJ)?
A attojoule (aJ) is a metric-prefixed unit of energy equal to 10-18 joules, a fraction of a single joule, using the SI atto prefix.
What is British thermal unit (BTU)?
The British thermal unit (BTU) is the energy needed to raise one pound of water by one degree Fahrenheit, widely used for heating and air-conditioning ratings.
How do I convert attojoules to btu?
Multiply the attojoule value by 9.478171203e-22 to get the equivalent in btu. For example, 5 aJ × 9.478171203e-22 = 4.739086e-21 BTU.
Is this conversion exact?
Yes. Both units are defined against the SI base unit for this dimension, so the factor 9.478171203e-22 is an exact, non-rounded value.
Can I convert btu back to attojoules?
Yes. Divide the british thermal unit value by 9.478171203e-22, or multiply it by 1.055055853e+21, to get attojoules.
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About converting attojoules to btu
A attojoule (aJ) is a metric-prefixed unit of energy equal to 10-18 joules, a fraction of a single joule, using the SI atto prefix. The British thermal unit (BTU) is the energy needed to raise one pound of water by one degree Fahrenheit, widely used for heating and air-conditioning ratings.
Use this calculator to move between attojoules and btu accurately for homework, engineering, billing, or everyday energy calculations. The Universal Converter uses exact unit factors, so results stay consistent across the site.