Convert Foot-pounds to British thermal units
1 foot-pound is 0.001285 BTU. One foot-pound is exactly 0.00128506746346 British thermal units.
One foot-pound is 0.0012850675 British thermal units. To convert foot-pounds to British thermal units, multiply by 0.0012850675; to go the other way, divide by 0.0012850675 or multiply by 778.16926. The factor is exact rather than rounded: it follows from NIST Special Publication 811. A pound-force acting through one foot.
Factor checked against the defining standard · How we check
- Foot-pounds × 0.0012850675
value * 0.001285067463460.001 BTU
1 foot-pound in every energy unit
| Unit | Value | Exact factor |
|---|---|---|
| joules | 1.355817948 J | × 1.35581794833 |
| kilojoules | 0.001355817948 kJ | × 0.00135581794833 |
| calories | 0.3240482668 cal | × 0.32404826681 |
| kilocalories | 0.0003240482668 kcal | × 0.00032404826681 |
| watt-hours | 0.0003766160968 Wh | × 0.000376616096759 |
| kilowatt-hours | 0.0000003766160968 kWh | × 0.000000376616096759 |
| British thermal units | 0.001285067463 BTU | × 0.00128506746346 |
| foot-pounds (as entered) | 1 ft·lbf | — |
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 foot-pounds to British thermal units?
- 1.Take the measurement in foot-pounds.
- 2.Multiply by 0.0012850675 — that is how many British thermal units fit in one foot-pound.
- 3.To go back the other way, divide by 0.0012850675, or multiply by 778.16926.
Worked example: 25 foot-pounds to British thermal units
- Formula
- ft·lbf × 0.0012850675 = BTU
- Arithmetic
- 25 × 0.0012850675 = 0.032127 BTU
- Answer
- 25 ft·lbf = 0.032127 BTU
The factor is rounded for display; the figure above is computed from the full value.
Foot-pounds to British thermal units conversion table
| Foot-pounds | British thermal units |
|---|---|
| 1 ft·lbf | 0.001285 BTU |
| 2 ft·lbf | 0.00257 BTU |
| 3 ft·lbf | 0.003855 BTU |
| 4 ft·lbf | 0.00514 BTU |
| 5 ft·lbf | 0.006425 BTU |
| 6 ft·lbf | 0.00771 BTU |
| 7 ft·lbf | 0.008995 BTU |
| 8 ft·lbf | 0.010281 BTU |
| 9 ft·lbf | 0.011566 BTU |
| 10 ft·lbf | 0.012851 BTU |
| 12 ft·lbf | 0.015421 BTU |
| 15 ft·lbf | 0.019276 BTU |
| 20 ft·lbf | 0.025701 BTU |
| 25 ft·lbf | 0.032127 BTU |
| 50 ft·lbf | 0.064253 BTU |
| 100 ft·lbf | 0.128507 BTU |
| 200 ft·lbf | 0.257013 BTU |
| 300 ft·lbf | 0.38552 BTU |
| 500 ft·lbf | 0.642534 BTU |
| 1000 ft·lbf | 1.285067 BTU |
| 2000 ft·lbf | 2.570135 BTU |
| 5000 ft·lbf | 6.425337 BTU |
| 10000 ft·lbf | 12.850675 BTU |
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.
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.
How many British thermal units are in a foot-pound?
One foot-pound is 0.0012850675 British thermal units. Going the other way, one British thermal unit is 778.16926 foot-pounds. 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 British thermal units are in a foot-pound?
- 0.0012850675. 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.
- How do I convert British thermal units back to foot-pounds?
- Divide by 0.0012850675, or multiply by 778.16926 — they are the same operation.
Other energy conversions
British thermal units to foot-pounds — the same conversion the other way.