hp To ft lbs
One horsepower is 33,000 foot-pounds of work every minute, which is how the unit began.
Quick answer: Multiply the horsepower by 33,000. For example, 1 hp is 33,000 ft-lbf/min, 10 hp is 330,000 ft-lbf/min and 100 hp is 3,300,000 ft-lbf/min.
The hp to ft-lbf per minute formula
Power in foot-pounds per minute equals horsepower times 33,000.
For foot-pounds per second, multiply by 550 instead.
Take 1 hp. 1 × 33,000 gives 33,000 ft-lbf/min.
Take 10 hp. 10 × 33,000 gives 330,000 ft-lbf/min.
Where 33,000 comes from
James Watt and Matthew Boulton set the horsepower at 33,000 foot-pounds of work per minute (Wikipedia: Horsepower). That is 550 foot-pounds every second.
In watts it works out to about 745.7.
How to convert hp to ft-lbf per minute step by step
- Read the power in horsepower.
- Multiply it by 33,000 for foot-pounds per minute.
- Or multiply by 550 for foot-pounds per second.
- Write the unit after the answer.
Example 1: 1 hp
- Start with 1 hp.
- 1 × 33,000 = 33,000.
- The power is 33,000 ft-lbf/min.
1 hp = 33,000 ft-lbf/min
Example 2: 10 hp
- Start with 10 hp.
- 10 × 33,000 = 330,000.
- The power is 330,000 ft-lbf/min.
10 hp = 330,000 ft-lbf/min
Example 3: 100 hp
- Start with 100 hp.
- 100 × 33,000 = 3,300,000.
- The power is 3,300,000 ft-lbf/min.
100 hp = 3,300,000 ft-lbf/min
Example 4: 5 hp
- Start with 5 hp.
- 5 × 33,000 = 165,000.
- The power is 165,000 ft-lbf/min.
5 hp = 165,000 ft-lbf/min
Example 5: 50 hp
- Start with 50 hp.
- 50 × 33,000 = 1,650,000.
- The power is 1,650,000 ft-lbf/min.
50 hp = 1,650,000 ft-lbf/min
Example 6: 2 hp
- Start with 2 hp.
- 2 × 33,000 = 66,000.
- The power is 66,000 ft-lbf/min.
2 hp = 66,000 ft-lbf/min
Round only at the end. Rounding in the middle of a sum adds small errors that grow.
hp to ft-lbf per minute conversion table
| Horsepower (hp) | Foot-pounds per minute (ft-lbf/min) | Foot-pounds per second (ft-lbf/s) |
|---|---|---|
| 0.1 hp | 3,300 ft-lbf/min | 55 Foot-pounds per second (ft-lbf/s) |
| 0.25 hp | 8,250 ft-lbf/min | 137.5 Foot-pounds per second (ft-lbf/s) |
| 0.5 hp | 16,500 ft-lbf/min | 275 Foot-pounds per second (ft-lbf/s) |
| 1 hp | 33,000 ft-lbf/min | 550 Foot-pounds per second (ft-lbf/s) |
| 2 hp | 66,000 ft-lbf/min | 1,100 Foot-pounds per second (ft-lbf/s) |
| 5 hp | 165,000 ft-lbf/min | 2,750 Foot-pounds per second (ft-lbf/s) |
| 10 hp | 330,000 ft-lbf/min | 5,500 Foot-pounds per second (ft-lbf/s) |
| 20 hp | 660,000 ft-lbf/min | 11,000 Foot-pounds per second (ft-lbf/s) |
| 50 hp | 1,650,000 ft-lbf/min | 27,500 Foot-pounds per second (ft-lbf/s) |
| 100 hp | 3,300,000 ft-lbf/min | 55,000 Foot-pounds per second (ft-lbf/s) |
| 250 hp | 8,250,000 ft-lbf/min | 137,500 Foot-pounds per second (ft-lbf/s) |
| 500 hp | 16,500,000 ft-lbf/min | 275,000 Foot-pounds per second (ft-lbf/s) |
The highlighted row is the default of the calculator. The last column gives Foot-pounds per second (ft-lbf/s).
A quick mental shortcut for hp to ft-lbf per minute
Think in tens of thousands. 3 hp is about 100,000 ft-lbf/min.
For per second, multiply by 550. 2 hp is 1,100 ft-lbf/s.
Power is not torque
Foot-pounds can mean work, energy or torque. This page is about work done per minute, which is power.
Engine torque in lb-ft is a different quantity. Use the hp to torque page for that.
The link with rpm
Torque in lb-ft times rpm divided by 5,252 gives horsepower. The 5,252 comes from 33,000 divided by 2 pi (Wikipedia: Horsepower).
So the two ideas connect through the 33,000 figure.
Lifting example
Lifting 550 pounds by one foot in one second is one horsepower. Lifting 33,000 pounds by one foot in one minute is the same power.
Both give 33,000 ft-lbf/min.
Quick conversion answers
| Conversion | Result |
|---|---|
| 1 hp | 33,000 ft-lbf/min |
| 10 hp | 330,000 ft-lbf/min |
| 100 hp | 3,300,000 ft-lbf/min |
| 1,000 hp | 33,000,000 ft-lbf/min |
Where this conversion is used
Students meet the original definition of horsepower.
Engineers move between imperial work rates and horsepower.
Common mistakes to avoid
- Mixing power and torque. Torque in ft-lbs is not a rate of work.
- Mixing per minute and per second. The factors are 33,000 and 550.
- Using 745.7 here. That factor is for watts.
- Forgetting the time unit. Write /min or /s after ft-lbf.
Related converters
More values at a glance
0.02 hp is 660 ft-lbf/min. 0.3 hp is 9,900 ft-lbf/min. 0.75 hp is 24,750 ft-lbf/min.
1.5 hp is 49,500 ft-lbf/min. 3 hp is 99,000 ft-lbf/min. 4 hp is 132,000 ft-lbf/min.
15 hp is 495,000 ft-lbf/min. 25 hp is 825,000 ft-lbf/min. 200 hp is 6,600,000 ft-lbf/min.
Common horsepower ratings
0.25 hp is 8,250 ft-lbf/min. 0.5 hp is 16,500 ft-lbf/min. 2 hp is 66,000 ft-lbf/min.
3 hp is 99,000 ft-lbf/min. 5 hp is 165,000 ft-lbf/min. 10 hp is 330,000 ft-lbf/min.
20 hp is 660,000 ft-lbf/min. 50 hp is 1,650,000 ft-lbf/min. 100 hp is 3,300,000 ft-lbf/min.
More worked values
1 hp is 33,000 ft-lbf/min. 2 hp is 66,000 ft-lbf/min. 4 hp is 132,000 ft-lbf/min.
8 hp is 264,000 ft-lbf/min. 15 hp is 495,000 ft-lbf/min. 25 hp is 825,000 ft-lbf/min.
40 hp is 1,320,000 ft-lbf/min. 75 hp is 2,475,000 ft-lbf/min. 100 hp is 3,300,000 ft-lbf/min.
Going the other way
To turn ft-lbf/min back into hp, do the opposite step.
1 ft-lbf/min is 0.00003 hp. 5 ft-lbf/min is 0.000152 hp. 10 ft-lbf/min is 0.000303 hp.
20 ft-lbf/min is 0.000606 hp. 50 ft-lbf/min is 0.001515 hp. 100 ft-lbf/min is 0.00303 hp.
250 ft-lbf/min is 0.007576 hp. 500 ft-lbf/min is 0.015152 hp.
A full worked example
Take 7.5 hp. Multiply by 33,000 to get 247,500 ft-lbf/min.
Now check it. Turn 247,500 ft-lbf/min back into hp and you should land on 7.5 again.
If you do not, look for a slipped decimal point or a swapped unit.
Rounding the answer
Keep about as many digits as your input has. For example, 12.3456 hp is 407,404.8 ft-lbf/min, which is 407,404.8 ft-lbf/min to 2 decimals.
Round only at the end. Rounding early can add a small error to the final number.
Small and large values
0.1 hp is 3,300 ft-lbf/min. 0.25 hp is 8,250 ft-lbf/min. 0.5 hp is 16,500 ft-lbf/min.
3 hp is 99,000 ft-lbf/min. 6 hp is 198,000 ft-lbf/min. 12 hp is 396,000 ft-lbf/min.
30 hp is 990,000 ft-lbf/min. 60 hp is 1,980,000 ft-lbf/min. 150 hp is 4,950,000 ft-lbf/min.
200 hp is 6,600,000 ft-lbf/min. 300 hp is 9,900,000 ft-lbf/min. 400 hp is 13,200,000 ft-lbf/min.
More values in the reverse direction
2 ft-lbf/min is 0.000061 hp. 3 ft-lbf/min is 0.000091 hp. 25 ft-lbf/min is 0.000758 hp.
30 ft-lbf/min is 0.000909 hp. 40 ft-lbf/min is 0.001212 hp. 60 ft-lbf/min is 0.001818 hp.
75 ft-lbf/min is 0.002273 hp. 200 ft-lbf/min is 0.006061 hp. 400 ft-lbf/min is 0.012121 hp.
1,000 ft-lbf/min is 0.030303 hp.
Frequently asked questions
How many Foot-pounds per minute is 1 hp?
1 hp is 33,000 ft-lbf/min.
How many Foot-pounds per minute is 10 hp?
10 hp is 330,000 ft-lbf/min.
How many Horsepower is 1 ft-lbf/min?
1 ft-lbf/min is 0.00003030303 hp.
How many foot-pounds per second is 1 hp?
1 hp is 550 ft-lbf/s.
How many foot-pounds per minute is 5 hp?
5 hp is 165,000 ft-lbf/min.
Is ft-lbs the same as horsepower?
No. Ft-lbs can mean torque or energy. Horsepower is work per unit of time.
Sources
- Wikipedia: Horsepower (en.wikipedia.org)
