Convert Foot-Pound per Second to Volt-Ampere (ft·lbf/s → VA)

Converting foot-pounds per second to volt-amperes is straightforward: multiply by the conversion factor. Follow these three steps to do it by hand or in your head.

1. 1
   Take your value in foot-pounds per second

   Start with the number of foot-pounds per second (ft·lbf/s) you want to convert.
2. 2
   Multiply by 1.355818

   The conversion factor from ft·lbf/s to VA is 1.355818. Multiply your value by this number.
3. 3
   Read the result in volt-amperes

   The result is your value in volt-amperes (VA).

Multiply the value in foot-pounds per second by 1.355818. For the reverse direction, multiply by 0.737562.

• ✓1 ft·lbf/s = 1.356 W.
• ✓550 ft·lbf/s = 1 mechanical hp.
• ✓Rarely needed today outside archival references.

• ✗Confusing ft·lbf/s (power) with ft·lbf (torque or work).
• ✗Using in modern specifications — prefer W or kW.
• ✗Mixing with foot-pound (energy) in same calculation.

What is the Foot-Pound per Second?

The foot-pound per second (ft·lb/s) is the American mechanical-power unit, used in engineering and machine-rating contexts. James Watt's original definition of 1 horsepower was 33,000 ft·lb/min = 550 ft·lb/s, so the foot-pound per second is the granular American power unit underlying horsepower calculations. It is rare in everyday use (kW or hp dominate American power specifications) but appears in engineering thermodynamics textbooks, mechanical-design calculations, and ballistics-energy contexts. The ft·lb/s relates to the watt (1 ft·lb/s ≈ 1.356 W), horsepower (550 ft·lb/s = 1 hp), and the BTU per hour (1 ft·lb/s ≈ 4.626 BTU/h). It is part of the legacy US customary unit system that retains a foothold in mechanical engineering despite metric advancement.

• Older US mechanical-engineering calculations
• Some US physics textbooks
• Classical-mechanics problems

What is the Volt-Ampere?

The volt-ampere (VA) is the SI unit of apparent power in alternating-current (AC) electrical systems. Equal to volts times amperes, the VA represents the magnitude of power flowing in an AC circuit before accounting for the phase relationship between voltage and current. For purely resistive loads (incandescent bulbs, heaters), 1 VA = 1 W. For reactive loads (motors, transformers, fluorescent lights), the apparent power (VA) is larger than the real power (W) because of the phase shift — the ratio is the 'power factor.' Transformers, UPS units, and generators are rated in VA or kVA (kilo-VA) because they must handle the apparent power, not just the real power. A typical home UPS for a desktop computer is 600–1,500 VA. The VA relates to the watt (1 VA = 1 W only at unity power factor), the kilovolt-ampere (1 kVA = 1,000 VA), and the megavolt-ampere (1 MVA = 10⁶ VA — used in utility-scale transformers).

• Transformer sizing
• Uninterruptible power supply (UPS) ratings
• Generator capacity