The US therm is a natural-gas billing unit equal to 100,000 BTU, used by utilities to measure gas usage.
Therms to Calories
Convert US therm (therm) to Calorie (cal) instantly with an exact formula, conversion table, and FAQ.
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Convert therms (therm) to calories (cal) instantly with formula, conversion table, and FAQ.
Context values
Some unit families need one extra value for a physically accurate result.
A (small) calorie is a thermochemical unit of heat energy equal to 4.184 joules, historically the energy needed to raise 1 gram of water by 1°C.
cal = therm × 25210420.65
Results update instantly for Therms to Calories conversions.
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Formula
cal = therm × 25210420.65
therm = cal × 3.966613703e-08
Conversion table
| 1 therm | 2.521042e+07 cal |
| 5 therm | 1.260521e+08 cal |
| 10 therm | 2.521042e+08 cal |
| 20 therm | 5.042084e+08 cal |
| 50 therm | 1.260521e+09 cal |
| 100 therm | 2.521042e+09 cal |
| 500 therm | 1.260521e+10 cal |
| 1000 therm | 2.521042e+10 cal |
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How the formula works
Both us therm and calorie measure the same physical quantity, so converting between them is a single multiplication. Multiply a value in therms by 25210420.65 to get calories. To reverse the conversion, multiply a calorie value by 3.966613703e-08 to get back to therms.
Frequently asked questions
What is US therm (therm)?
The US therm is a natural-gas billing unit equal to 100,000 BTU, used by utilities to measure gas usage.
What is Calorie (cal)?
A (small) calorie is a thermochemical unit of heat energy equal to 4.184 joules, historically the energy needed to raise 1 gram of water by 1°C.
How do I convert therms to calories?
Multiply the us therm value by 25210420.65 to get the equivalent in calories. For example, 5 therm × 25210420.65 = 1.260521e+08 cal.
Is this conversion exact?
Yes. Both units are defined against the SI base unit for this dimension, so the factor 25210420.65 is an exact, non-rounded value.
Can I convert calories back to therms?
Yes. Divide the calorie value by 25210420.65, or multiply it by 3.966613703e-08, to get therms.
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About converting therms to calories
The US therm is a natural-gas billing unit equal to 100,000 BTU, used by utilities to measure gas usage. A (small) calorie is a thermochemical unit of heat energy equal to 4.184 joules, historically the energy needed to raise 1 gram of water by 1°C.
Use this calculator to move between therms and calories accurately for homework, engineering, billing, or everyday energy calculations. The Universal Converter uses exact unit factors, so results stay consistent across the site.