You're comparing two machines. The older spec sheet lists its output as 250 foot pounds per second. The newer one claims 340 watts. Which one is more powerful?

Here's the surprise: they're practically identical. These two numbers describe the same amount of power, just measured in different systems. Once you understand how foot pounds per second and watts relate, you can read any motor plate, engine manual, or engineering document with confidence — no matter which side of the Atlantic it came from.

What Is a Foot Pound Per Second?

A foot pound per second (ft-lb/s) is a unit of power from the imperial and US customary systems. It measures how quickly work gets done.

To break it down: a foot pound is the energy used when a force of one pound moves an object a distance of one foot. Picture lifting a one-pound weight straight up by one foot. That effort equals one foot pound of work.

Add "per second" and you get power — the rate of doing that work. If a hoist lifts a one-pound load one foot every second, it's producing one foot pound per second of power.

What Is a Watt?

The watt (W) is the standard international (SI) unit of power, named after Scottish engineer James Watt. One watt equals one joule of energy transferred per second.

Watts are everywhere. Light bulbs, phone chargers, microwaves, and electric motors all list their power in watts. Because it belongs to the SI system, the watt is understood by engineers in every country on Earth.

The key idea: watts and foot pounds per second both measure power. They're just different languages for the same concept.

How to Convert Foot Pounds Per Second to Watts

The relationship between these units is fixed and exact. One foot pound per second equals approximately 1.35582 watts.

The Formula

Watts = Foot Pounds Per Second × 1.35582

Multiply any ft-lb/s value by 1.35582 and you have its equivalent in watts. For quick mental estimates, multiplying by 1.36 gets you close enough for everyday decisions.

Converting Back: Watts to Foot Pounds Per Second

Foot Pounds Per Second = Watts ÷ 1.35582

Divide the wattage by 1.35582 to return to imperial units. If you prefer multiplication, you can multiply watts by roughly 0.7376 instead — same result, different route.

Where You'll Encounter Foot Pounds Per Second

Even though the watt dominates modern specifications, foot pounds per second still shows up in plenty of places. Knowing how to translate between them keeps you sharp.

Legacy Engineering Documents

Much American machinery from the 20th century was rated in imperial units. Old pump curves, motor nameplates, and technical manuals often quote output in ft-lb/s. Converting to watts lets you compare those machines directly against modern equipment.

The Horsepower Connection

Here's a useful anchor point: one horsepower is defined as exactly 550 foot pounds per second. Run that through our conversion and you get about 746 watts — the figure you've probably seen on electric motor labels. Foot pounds per second sits right in the family tree of horsepower, which makes it a handy stepping stone between old and new rating systems.

Pumps, Winches, and Hoists

Lifting tasks map neatly onto this unit. Suppose a winch raises a 200-pound load at a steady one foot per second. That's 200 ft-lb/s of power — about 271 watts. Change the load or the speed, and the math scales in a way you can see and verify.

Human Power Output

Your own body produces measurable power. A person weighing 180 pounds who climbs stairs fast enough to gain 10 feet of height in 5 seconds is working at 2 feet per second vertically. That's 360 ft-lb/s, or roughly 488 watts — a solid sprint effort. Exercise physiologists and cycling coaches use these same relationships when analyzing performance.

Quick Conversion Table: ft-lb/s to Watts

Use this reference table for common values. Each figure uses the standard factor of 1.35582 watts per foot pound per second, rounded to two decimal places.

Common Mistakes to Avoid

• Confusing work with torque. A foot pound measures energy or work. A pound foot measures twisting force (torque). They share similar names and symbols, but they describe different things. In a power conversion, you're always dealing with work done over time.
• Rounding too early. If your calculation feeds into a bigger project — sizing a motor, estimating energy costs — carry extra decimal places through each step and round only at the end.
• Assuming the units are interchangeable. A number in ft-lb/s plugged into a formula expecting watts will be off by about 36%. Always convert first, then calculate.
• Forgetting the direction of conversion. Going from ft-lb/s to watts means multiplying by 1.35582. Going the other way means dividing. Writing the formula down before you start prevents flipped results.

The Bottom Line

Foot pounds per second and watts are two dialects of the same language: power. The imperial unit ties back to familiar weights and distances, while the watt connects to the global scientific standard. With the fixed factor of 1.35582 in your toolkit, you can move between them instantly — whether you're restoring vintage machinery, comparing motor specs, or just settling a debate about which machine works harder.

Need another conversion while you're at it? Scroll back up and let the tool handle the math for you — it's faster than any formula scribbled on a napkin.