Authoritative definitions of the International System of Units and SI prefixes.
Dedicated unit pair
Therms to British thermal units
Convert thm to BTU instantly, then review the formula, assumptions, and rounding guidance.
Thermal unitsInstant result
Decimals
Formula result = input × 105505585.257 ÷ 1055.055853. 1 thm = 100,000 BTU
Common examples
One value, several units
Joules105,505,585.257 J
Kilojoules105,505.5853 kJ
Calories25,216,440.071 cal
Kilocalories25,216.4401 kcal
British thermal units100,000 BTU
Conversion table
| thm | BTU |
|---|---|
| 1 thm | 100,000 BTU |
| 2 thm | 199,999.9999 BTU |
| 5 thm | 499,999.9998 BTU |
| 10 thm | 999,999.9996 BTU |
| 25 thm | 2,499,999.999 BTU |
| 50 thm | 4,999,999.998 BTU |
| 100 thm | 9,999,999.9959 BTU |
Conversion chart
1 thm100,000 BTU
5 thm499,999.9998 BTU
10 thm999,999.9996 BTU
25 thm2,499,999.999 BTU
50 thm4,999,999.998 BTU
Worked example
1 BTU is approximately 1,055.06 joules.
Unit definition
Therms (thm) One therms equals 105,505,585.257 joule.
Unit history
Therms is represented here using its modern SI definition or an internationally accepted relationship to an SI base unit.
Step by step
1. Parse the value, including fractions.
2. Convert thm to joule.
3. Convert the base value to BTU and apply your display precision.
Understand the result before using it
Therms to British thermal units converts a value measured in Therms (thm) into the equivalent value in British thermal units (BTU). The numerical value changes because the size and definition of the selected unit changes; the underlying quantity does not.
Calculated result
The conversion follows the displayed unit relationship. Display rounding can hide additional digits, and measured inputs cannot become more accurate merely by changing units.
Formula, assumptions, and example
Formula
result = input × 105505585.257 ÷ 1055.055853
Assumptions
- Therms and British thermal units represent the same thermal units quantity.
- The input is expressed in thm; the output is expressed in BTU.
- The unit definitions and conventional relationship shown on this page apply.
Worked example
1 thm = 99,999.9999592 BTU. For another value, apply the same relationship and round only to the precision your source measurement supports.
When to use it
Good uses
- Read a thm measurement in a document that expects BTU.
- Compare a therms value with a value reported in british thermal units.
- Check the thm-to-BTU arithmetic before copying the result into another calculation.
Limitations
Common mistakes to avoid
- Do not confuse thm with another unit that has a similar name or symbol.
- Round the output to a precision justified by the original measurement.
- Verify safety-critical, regulated, laboratory, and contractual conversions against the controlling standard.
Sources and further reading
These references explain the underlying standards or provide authoritative context. Your own contract, institution, clinician, product documentation, local code, or governing standard may be the controlling source.
Guidance on unit names, symbols, conversions, and numerical presentation.
Questions about this calculation
How do I convert Therms to British thermal units?
result = input × 105505585.257 ÷ 1055.055853 Using the displayed relationship, 1 thm equals 99,999.9999592 BTU.
How many British thermal units are in one Therms?
One Therms is 99,999.9999592 British thermal units. The displayed digits may be rounded.
Can I reverse the thm to BTU conversion?
Yes. Swap the source and target units in the converter. The reverse relationship converts BTU back to thm.
Is the Therms to British thermal units result exact?
The conversion follows the displayed unit relationship. Display rounding can hide additional digits, and measured inputs cannot become more accurate merely by changing units.