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| Unit | Name | Value |
|---|---|---|
| 0.001 ft·lb | 13558.2 erg | |
| 0.01 ft·lb | 135582 erg | |
| 0.1 ft·lb | 1.35582e+06 erg | |
| 1 ft·lb | 1.35582e+07 erg | |
| 5 ft·lb | 6.7791e+07 erg | |
| 10 ft·lb | 1.35582e+08 erg | |
| 50 ft·lb | 6.7791e+08 erg | |
| 100 ft·lb | 1.35582e+09 erg | |
| 1000 ft·lb | 1.35582e+10 erg |
Formula: Erg = Foot-Pound × 1.356e+07
Multiply any foot-pound value by 1.356e+07 to get erg.
Reverse: Foot-Pound = Erg × 7.3756e-8
Common foot-pound values — factor: 1 ft·lb = 1.356e+07 erg
| Foot-Pound (ft·lb) | Erg (erg) | Context |
|---|---|---|
| 1 ft·lb | 1.356e+07 erg | 1 ft·lb |
| 10 ft·lb | 1.356e+08 erg | 10 ft·lb |
| 100 ft·lb | 1.356e+09 erg | 100 ft·lb |
| 350 ft·lb | 4.745e+09 erg | 9mm pistol |
| 550 ft·lb | 7.457e+09 erg | 1 HP/s |
| 1,000 ft·lb | 1.356e+10 erg | Rifle bullet |
| 3,000 ft·lb | 4.067e+10 erg | High-power rifle |
| 1e+04 ft·lb | 1.356e+11 erg | 10 kft·lb |
| 1e+05 ft·lb | 1.356e+12 erg | 100 kft·lb |
| 1e+06 ft·lb | 1.356e+13 erg | 1 Mft·lb |
| 1e+07 ft·lb | 1.356e+14 erg | 10 Mft·lb |
| 1.000e+09 ft·lb | 1.356e+16 erg | 1 Gft·lb |
| 1.000e+12 ft·lb | 1.356e+19 erg | 1 Tft·lb |
| 1.000e+15 ft·lb | 1.356e+22 erg | 1 Pft·lb |
| 1.000e+18 ft·lb | 1.356e+25 erg | 1 Eft·lb |
1 ft·lb = 1.356e+07 erg. Memorize for instant estimates.
Use 1.356e+07 as a quick mental multiplier.
Multiply result by 7.3756e-8 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 erg is the unit of energy in the CGS (centimeter-gram-second) system, equal to exactly 10⁻⁷ joules. It was defined by the British Association for the Advancement of Science in 1882 as the work done by a force of one dyne over one centimeter.
Ergs were widely used in 19th and early 20th century physics before SI standardization. They remain in use in astrophysics (stellar luminosities in erg/s) and some older scientific literature.
Interesting fact: The Sun radiates about 3.8 × 10³³ ergs per second. A mosquito in flight exerts about 100 ergs of energy per wingbeat. One joule = 10,000,000 ergs exactly.
Converting foot-pound to erg 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 = 6.779e+07 erg and 10 ft·lb = 1.356e+08 erg. Reverse: 1 erg = 7.3756e-8 ft·lb. Exact factor: 1 ft·lb = 1.356e+07 erg.
All conversions use IEEE 754 double-precision arithmetic, accurate to at least 8 significant figures.