Convert British thermal units to Foot-pounds
1 British thermal unit is 778.169262 ft·lbf. One British thermal unit is exactly 778.169262266 foot-pounds.
One British thermal unit is 778.16926 foot-pounds. To convert British thermal units to foot-pounds, multiply by 778.16926; to go the other way, divide by 778.16926 or multiply by 0.0012850675. The factor is exact rather than rounded: it follows from NIST Special Publication 811. The international-table BTU, fixed at exactly 1055.05585262 joules.
Factor checked against the defining standard · How we check
- British thermal units × 778.16926
value * 778.169262266778.169 ft·lbf
1 British thermal unit in every energy unit
| Unit | Value | Exact factor |
|---|---|---|
| joules | 1,055.055853 J | × 1,055.05585262 |
| kilojoules | 1.055055853 kJ | × 1.05505585262 |
| calories | 252.1644007 cal | × 252.164400722 |
| kilocalories | 0.2521644007 kcal | × 0.252164400722 |
| watt-hours | 0.2930710702 Wh | × 0.293071070172 |
| kilowatt-hours | 0.0002930710702 kWh | × 0.000293071070172 |
| British thermal units (as entered) | 1 BTU | — |
| foot-pounds | 778.1692623 ft·lbf | × 778.169262266 |
Factors are entered by hand from NIST Special Publication 811 rather than derived from a units library, so the ones that terminate are exact rather than rounded.
How do you convert British thermal units to foot-pounds?
- 1.Take the measurement in British thermal units.
- 2.Multiply by 778.16926 — that is how many foot-pounds fit in one British thermal unit.
- 3.To go back the other way, divide by 778.16926, or multiply by 0.0012850675.
Worked example: 25 British thermal units to foot-pounds
- Formula
- BTU × 778.16926 = ft·lbf
- Arithmetic
- 25 × 778.16926 = 19,454.231557 ft·lbf
- Answer
- 25 BTU = 19,454.231557 ft·lbf
The factor is rounded for display; the figure above is computed from the full value.
British thermal units to foot-pounds conversion table
| British thermal units | Foot-pounds |
|---|---|
| 1 BTU | 778.169262 ft·lbf |
| 2 BTU | 1,556.338525 ft·lbf |
| 3 BTU | 2,334.507787 ft·lbf |
| 4 BTU | 3,112.677049 ft·lbf |
| 5 BTU | 3,890.846311 ft·lbf |
| 6 BTU | 4,669.015574 ft·lbf |
| 7 BTU | 5,447.184836 ft·lbf |
| 8 BTU | 6,225.354098 ft·lbf |
| 9 BTU | 7,003.52336 ft·lbf |
| 10 BTU | 7,781.692623 ft·lbf |
| 12 BTU | 9,338.031147 ft·lbf |
| 15 BTU | 11,672.538934 ft·lbf |
| 20 BTU | 15,563.385245 ft·lbf |
| 25 BTU | 19,454.231557 ft·lbf |
| 50 BTU | 38,908.463113 ft·lbf |
| 100 BTU | 77,816.926227 ft·lbf |
| 200 BTU | 155,633.852453 ft·lbf |
| 300 BTU | 233,450.77868 ft·lbf |
| 500 BTU | 389,084.631133 ft·lbf |
| 1000 BTU | 778,169.262266 ft·lbf |
| 2000 BTU | 1,556,338.524532 ft·lbf |
| 5000 BTU | 3,890,846.31133 ft·lbf |
| 10000 BTU | 7,781,692.62266 ft·lbf |
What is a British thermal unit?
The international-table BTU, fixed at exactly 1055.05585262 joules. Roughly the heat needed to raise a pound of water by one degree Fahrenheit, which is where it came from.
What is a foot-pound?
A pound-force acting through one foot. The same arithmetic as the torque unit of that name, and a different quantity: this one is work done, not twist applied.
How many foot-pounds are in a British thermal unit?
One British thermal unit is 778.16926 foot-pounds. Going the other way, one foot-pound is 0.0012850675 British thermal units. Both figures come from the same defined relation rather than from a measurement, which is why they are the same today as they were in 1959.
Every energy unit here
| Unit | Symbol | One of these is |
|---|---|---|
| Joules | J | the base unit |
| Kilojoules | kJ | 1000 joule |
| Calories | cal | 4.184 joule |
| Kilocalories | kcal | 4184 joule |
| Watt-hours | Wh | 3600 joule |
| Kilowatt-hours | kWh | 3600000 joule |
| British thermal units | BTU | 1055.0559 joule |
| Foot-pounds | ft·lbf | 1.3558179 joule |
Source: NIST Special Publication 811 — the thermochemical calorie is exactly 4.184 J
Questions people actually ask
- How many foot-pounds are in a British thermal unit?
- 778.16926. A pound-force acting through one foot. The same arithmetic as the torque unit of that name, and a different quantity: this one is work done, not twist applied.
- How do I convert foot-pounds back to British thermal units?
- Divide by 778.16926, or multiply by 0.0012850675 — they are the same operation.
Other energy conversions
Foot-pounds to British thermal units — the same conversion the other way.