Convert energy units — joules, kilowatt-hours, calories, BTU, electron volts and more.
| Unit | Name | Value |
|---|---|---|
| 0.001 ft·lb | 1.285e-11 therm | |
| 0.01 ft·lb | 1.285e-10 therm | |
| 0.1 ft·lb | 1.28538e-09 therm | |
| 1 ft·lb | 1.28538e-08 therm | |
| 5 ft·lb | 6.42688e-08 therm | |
| 10 ft·lb | 1.28538e-07 therm | |
| 50 ft·lb | 6.42688e-07 therm | |
| 100 ft·lb | 1.28538e-06 therm | |
| 1000 ft·lb | 1.28538e-05 therm |
Formula: Therm = Foot-Pound × 1.2854e-8
Multiply any foot-pound value by 1.2854e-8 to get therm.
Reverse: Foot-Pound = Therm × 7.78e+07
Common foot-pound values — factor: 1 ft·lb = 1.2854e-8 therm
| Foot-Pound (ft·lb) | Therm (therm) | Context |
|---|---|---|
| 1 ft·lb | 1.285e-08 therm | 1 ft·lb |
| 10 ft·lb | 1.285e-07 therm | 10 ft·lb |
| 100 ft·lb | 1.285e-06 therm | 100 ft·lb |
| 350 ft·lb | 4.499e-06 therm | 9mm pistol |
| 550 ft·lb | 7.070e-06 therm | 1 HP/s |
| 1,000 ft·lb | 1.285e-05 therm | Rifle bullet |
| 3,000 ft·lb | 3.856e-05 therm | High-power rifle |
| 1e+04 ft·lb | 0.0001285 therm | 10 kft·lb |
| 1e+05 ft·lb | 0.001285 therm | 100 kft·lb |
| 1e+06 ft·lb | 0.01285 therm | 1 Mft·lb |
| 1e+07 ft·lb | 0.1285 therm | 10 Mft·lb |
| 1.000e+09 ft·lb | 12.85 therm | 1 Gft·lb |
| 1.000e+12 ft·lb | 1.285e+04 therm | 1 Tft·lb |
| 1.000e+15 ft·lb | 1.285e+07 therm | 1 Pft·lb |
| 1.000e+18 ft·lb | 1.285e+10 therm | 1 Eft·lb |
1 ft·lb = 1.2854e-8 therm. Memorize for instant estimates.
Use 1.2854e-8 as a quick mental multiplier.
Multiply result by 7.78e+07 to recover the original ft·lb value.
Torques bolts and fasteners to specified ft·lb values using a torque wrench.
Rates firearm muzzle energy in ft·lb for US ammunition comparisons.
Calculates impact energy absorption in ft·lb for US building codes.
Measures and compares engine torque output in ft·lb on a dyno.
Specifies fall arrest and impact energy in ft·lb for OSHA compliance.
Evaluates hunting cartridge terminal energy in ft·lb for ethical dispatch.
The foot-pound (ft·lb) is an Imperial unit of energy equal to the work done when a force of one pound-force moves an object one foot, equaling 1.35582 joules. It has been used in British and American engineering since the 18th century.
Foot-pounds are standard in US mechanical engineering for torque specifications, engine output (often ft·lb of torque), and ballistic energy measurements. Rifle bullet energies are commonly quoted in foot-pounds in American publications.
Interesting fact: A typical 9mm pistol bullet has about 350 ft·lb of muzzle energy. The torque specification for tightening a car wheel bolt is typically 80–100 ft·lb. One horsepower equals 550 ft·lb per second.
The therm is a unit of natural gas energy equal to 100,000 BTU (105,480,400 joules). It is the standard billing unit for natural gas in the United States and United Kingdom. The name comes from the Greek thermos (heat).
Gas utilities bill residential and commercial customers in therms in the US and UK. A typical US household uses about 50–100 therms per month in winter. Natural gas furnaces and water heaters are rated in therms per hour.
Interesting fact: One therm of natural gas costs about $1.00–$2.00 in the US. Burning one therm releases about 5.3 kg of CO₂. The US consumes about 28 trillion therms of natural gas equivalent energy per year.
Converting foot-pound to therm is common across energy, nutrition, engineering, and science. Different sectors use different energy units — joules in physics, kcal in nutrition, kWh in electricity, and BTU in HVAC — making accurate conversion essential for cross-disciplinary work and international comparisons.
Quick reference: 5 ft·lb = 6.4269e-8 therm and 10 ft·lb = 1.2854e-7 therm. Reverse: 1 therm = 7.78e+07 ft·lb. Exact factor: 1 ft·lb = 1.2854e-8 therm.
All conversions use IEEE 754 double-precision arithmetic, accurate to at least 8 significant figures.