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 to Attojoules
Convert British thermal unit (BTU) to Attojoule (aJ) instantly with an exact formula, conversion table, and FAQ.
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Convert btu (BTU) to attojoules (aJ) instantly with formula, conversion table, and FAQ.
Context values
Some unit families need one extra value for a physically accurate result.
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.
aJ = BTU × 1.055055853e+21
Results update instantly for Btu to Attojoules conversions.
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Formula
aJ = BTU × 1.055055853e+21
BTU = aJ × 9.478171203e-22
Conversion table
| 1 BTU | 1.055056e+21 aJ |
| 5 BTU | 5.275279e+21 aJ |
| 10 BTU | 1.055056e+22 aJ |
| 20 BTU | 2.110112e+22 aJ |
| 50 BTU | 5.275279e+22 aJ |
| 100 BTU | 1.055056e+23 aJ |
| 500 BTU | 5.275279e+23 aJ |
| 1000 BTU | 1.055056e+24 aJ |
Related conversions
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How the formula works
Both british thermal unit and attojoule measure the same physical quantity, so converting between them is a single multiplication. Multiply a value in btu by 1.055055853e+21 to get attojoules. To reverse the conversion, multiply a attojoule value by 9.478171203e-22 to get back to btu.
Frequently asked questions
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.
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.
How do I convert btu to attojoules?
Multiply the british thermal unit value by 1.055055853e+21 to get the equivalent in attojoules. For example, 5 BTU × 1.055055853e+21 = 5.275279e+21 aJ.
Is this conversion exact?
Yes. Both units are defined against the SI base unit for this dimension, so the factor 1.055055853e+21 is an exact, non-rounded value.
Can I convert attojoules back to btu?
Yes. Divide the attojoule value by 1.055055853e+21, or multiply it by 9.478171203e-22, to get btu.
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About converting btu to attojoules
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. 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.
Use this calculator to move between btu and attojoules accurately for homework, engineering, billing, or everyday energy calculations. The Universal Converter uses exact unit factors, so results stay consistent across the site.