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Horsepower (HP) quantifies the mechanical power a device can deliver, while kilovolt‑amps (kVA) measure the apparent electrical power in a circuit—obtained by multiplying voltage by current. To translate a motor’s HP rating into the kVA it will consume, you need the motor’s rated horsepower and its efficiency.

Step 1

Multiply the horsepower by 746 (the number of watts in one HP). For example, 100 HP × 746 W/HP = 74,600 W.

Step 2

Adjust for the motor’s efficiency (expressed as a decimal). If the motor is 90 % efficient, multiply the result from Step 1 by 0.90: 74,600 W × 0.90 = 67,140 W.

Step 3

Convert watts to kilovolt‑amps by dividing by 1,000 (since 1 kVA = 1,000 VA). Thus, 67,140 W ÷ 1,000 = 67.14 kVA.

Note: kVA represents apparent power; the real power in kilowatts (kW) is kVA × power factor. Always verify the power factor for accurate sizing.