Work from one pound-force over one foot.
Foot-pounds to US therms Converter — ft-lb to therm
Convert Foot-pound (ft-lb) to US therm (therm) using the exact conversion factor (1 foot-pound = 1.285374e-8 us therm). See the formula, worked examples, and conversion table.
Foot-pounds to US therms converter
Converter
Engineering Converter
Convert common stress, force, torque, power, and energy units used in engineering.
Context values
Some unit families need one extra value for a physically accurate result.
US therm used for natural gas energy.
Result = input x 1.355817948 / 1.054804e+8.
Energy units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Foot-pounds to US therms
Foot-pound and US therm both measure a quantity used in structural or mechanical engineering — commonly stress, pressure, force, torque, power, or energy — where converting between the unit conventions used in different regions, industries, or equipment specifications is a routine part of design work. Specifically: Work from one pound-force over one foot, and uS therm used for natural gas energy.
Formula
us therms = foot-pounds × 1.285374e-8
This factor comes from each unit's defined relationship to the category's base unit: 1 foot-pound equals 1.35581794833 base units, and 1 us therm equals 105480400 base units, so dividing one by the other gives the direct foot-pound-to-us therm factor of 1.285374e-8.
Simple example
1 ft-lb × 1.285374e-8 = 1.285374e-8 therm
1 foot-pound = 1.285374e-8 us therms.
Real-world example
100 ft-lb × 1.285374e-8 = 0.0000012854 therm
100 foot-pounds = 0.0000012854 us therms.
Conversion table
| Foot-pound (ft-lb) | US therm (therm) |
|---|---|
| 1 ft-lb | 1.285374e-8 therm |
| 10 ft-lb | 1.285374e-7 therm |
| 50 ft-lb | 6.426871e-7 therm |
| 100 ft-lb | 0.0000012854 therm |
| 500 ft-lb | 0.0000064269 therm |
| 1,000 ft-lb | 0.0000128537 therm |
Reverse conversion: US therm to Foot-pound
1.285374e-8 therm × 77798350.53 = 0.9999997701 ft-lb
1.285374e-8 us therms = 0.9999997701 foot-pounds.
foot-pounds = us therms × 77798350.5306
For a page dedicated to this direction, see US therm to Foot-pound.
Understanding the Foot-pound (ft-lb)
Work from one pound-force over one foot.
Understanding the US therm (therm)
US therm used for natural gas energy.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many us therms are in 1 foot-pound?
1 foot-pound equals 1.285374e-8 us therms, using the exact defined conversion factor rather than an estimate.
How do I convert foot-pound to us therm?
Multiply the foot-pound value by 1.285374e-8. The converter above does this instantly to whatever precision you set.
How do I convert us therm back to foot-pound?
Use the reverse factor: 1 us therm equals 77,798,350.53 foot-pounds. You can also use the swap control in the converter above to flip the direction instantly.
What is a foot-pound?
Foot-pound (ft-lb) is a unit of engineering.
What is a us therm?
US therm (therm) is a unit of engineering.
Is the foot-pound to us therm conversion exact?
Yes. Both foot-pound and us therm are defined by fixed standards rather than physical artifacts, so the factor of 1.285374e-8 used above is exact to as many digits as you choose to display.
Why do engineering unit conventions vary so much by region and industry?
Pressure, force, and stress can be expressed in metric (pascal, newton), US customary (psi, pound-force), or older and industry-specific units (atmosphere, torr, kip) depending on the country, industry, and even the equipment manufacturer, which is why engineers routinely need to convert between them when working across specs from different sources.