Real to Apparent Power

kW to kVA Calculator

Sizing commercial backup generators and utility transformers. Calculates the total transformer or generator kVA rating required to deliver a desired kilowatt load.

kW to kVA Calculator
kW
PF
Calculated Result
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Instant Calculation
Engineering Output
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Auxiliary Output
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Step-by-Step Derivation ▼ Show Steps
Governing Formula Verified Physics
kVA = kW / Power Factor (PF)

Calculations adhere to standard electrical engineering physics and National Electrical Code (NFPA 70) regulations.

Engineering Principles & Calculations

This calculator uses the exact mathematical relationships between Active Power (kW), Power Factor (PF) to determine Required Apparent Power (kVA). In practical installations, factors such as ambient raceway temperature, harmonic distortion, duty cycle continuous operation, and conductor impedance must be accounted for by a certified electrician.

Calculates the total transformer or generator kVA rating required to deliver a desired kilowatt load.

Typical Application & Industry Guidelines

Sizing commercial backup generators and utility transformers.

Reference Matrix

kW to kVA Calculator Benchmark Lookup Table

Load kWkVA @ 0.70 PFkVA @ 0.80 PFkVA @ 0.90 PFkVA @ 0.95 PF
20 kW28.6 kVA25.0 kVA22.2 kVA21.1 kVA
50 kW71.4 kVA62.5 kVA55.6 kVA52.6 kVA
80 kW114.3 kVA100.0 kVA88.9 kVA84.2 kVA
150 kW214.3 kVA187.5 kVA166.7 kVA157.9 kVA
300 kW428.6 kVA375.0 kVA333.3 kVA315.8 kVA
FAQ

Frequently Asked Questions

How do you convert kW to kVA? +
Divide kW by the circuit Power Factor: kVA = kW / PF. For example, 80 kW at 0.80 PF requires 80 / 0.80 = 100 kVA.
Why does improving power factor reduce kVA requirements? +
Because apparent power (kVA) represents the total current the utility must deliver. Improving PF from 0.70 to 0.95 reduces the kVA capacity needed by over 26%, shrinking generator and transformer size.
What size transformer is needed for a 120 kW building load? +
At an estimated 0.80 PF, 120 kW / 0.80 = 150 kVA. A standard 150 kVA 3-phase commercial transformer would be specified.

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