Convert energy units — joules, kilowatt-hours, calories, BTU, electron volts and more.
| Unit | Name | Value |
|---|---|---|
| 0.001 ft·lb | 0.000324049 cal | |
| 0.01 ft·lb | 0.00324049 cal | |
| 0.1 ft·lb | 0.0324049 cal | |
| 1 ft·lb | 0.324049 cal | |
| 5 ft·lb | 1.62024 cal | |
| 10 ft·lb | 3.24049 cal | |
| 50 ft·lb | 16.2024 cal | |
| 100 ft·lb | 32.4049 cal | |
| 1000 ft·lb | 324.049 cal |
Formula: Calorie = Foot-Pound × 0.324
Multiply any foot-pound value by 0.324 to get calorie.
Reverse: Foot-Pound = Calorie × 3.086
Common foot-pound values — factor: 1 ft·lb = 0.324 cal
| Foot-Pound (ft·lb) | Calorie (cal) | Context |
|---|---|---|
| 1 ft·lb | 0.324 cal | 1 ft·lb |
| 10 ft·lb | 3.24 cal | 10 ft·lb |
| 100 ft·lb | 32.4 cal | 100 ft·lb |
| 350 ft·lb | 113.4 cal | 9mm pistol |
| 550 ft·lb | 178.2 cal | 1 HP/s |
| 1,000 ft·lb | 324 cal | Rifle bullet |
| 3,000 ft·lb | 972.1 cal | High-power rifle |
| 1e+04 ft·lb | 3,240 cal | 10 kft·lb |
| 1e+05 ft·lb | 3.24e+04 cal | 100 kft·lb |
| 1e+06 ft·lb | 3.24e+05 cal | 1 Mft·lb |
| 1e+07 ft·lb | 3.24e+06 cal | 10 Mft·lb |
| 1.000e+09 ft·lb | 3.24e+08 cal | 1 Gft·lb |
| 1.000e+12 ft·lb | 3.240e+11 cal | 1 Tft·lb |
| 1.000e+15 ft·lb | 3.240e+14 cal | 1 Pft·lb |
| 1.000e+18 ft·lb | 3.240e+17 cal | 1 Eft·lb |
1 ft·lb = 0.324 cal. Memorize for instant estimates.
Use 0.324 as a quick mental multiplier.
Multiply result by 3.086 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 calorie (cal) was defined in 1824 as the heat needed to raise 1 gram of water by 1°C. There are two versions: the small calorie (cal = 4.184 J) and the large calorie or kilocalorie (kcal = 4,184 J), which is the 'Calorie' used in nutrition.
The calorie remains standard in chemistry for heat of reaction measurements. In the US, food packaging uses 'Calories' (with capital C) which are actually kilocalories — a persistent source of confusion.
Interesting fact: The confusion between cal and kcal means that a food label saying '200 Calories' actually means 200 kcal = 200,000 cal = 836,800 joules. The SI unit for food energy is the kilojoule.
Converting foot-pound to calorie 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 = 1.62 cal and 10 ft·lb = 3.24 cal. Reverse: 1 cal = 3.086 ft·lb. Exact factor: 1 ft·lb = 0.324 cal.
All conversions use IEEE 754 double-precision arithmetic, accurate to at least 8 significant figures.