kVA to Amperes Calculator
Convert apparent power to current. Critical for sizing generators, transformers, and industrial distribution boards where total capacity is rated in kVA.
Distribution Analysis
Apparent Power → Current
Calculated current per phase for distribution panels.
The Conversion Formula
kVA to amps conversion differs between single-phase and three-phase systems.
Single-Phase AC
I = (kVA × 1000) ÷ V kVA already includes power factor — no PF input needed. Used for UPS systems, generators, and single-phase transformers.
Three-Phase AC
I = (kVA × 1000) ÷ (√3 × V) Three-phase apparent power uses line-to-line voltage with the √3 (1.732) factor. Standard for industrial generators and transformers.
How to Convert kVA to Amps
kVA (kilovolt-amperes) is a measure of apparent power — the total power a source must supply, including both real work and reactive power. Unlike kW which measures only real power, kVA is the rating used for generators, UPS systems, and transformers because these devices must supply whatever current is demanded regardless of the load's power factor.
kVA vs. kW: The Key Difference
kW = kVA × Power Factor. A 10 kVA generator powering a load with 0.8 PF delivers only 8 kW of real power. Always size generators and UPS units in kVA — the kW figure alone will lead to undersizing if your loads have poor power factors.
Where kVA Ratings Are Used
- Generators: All generator output capacity is rated in kVA. A 20 kVA generator at 0.8 PF produces 16 kW of real power.
- UPS Systems: Uninterruptible power supplies use kVA ratings. Match the kVA rating to your total load's apparent power, not just its watt draw.
- Transformers: Transformer capacity is always in kVA. The secondary current rating determines what wire gauge and protection you need.
- HVAC Equipment: Large commercial air conditioning units may publish kVA demand for electrical planning purposes.
Step-by-Step Conversion
- Find the kVA Rating: Read it from the generator, UPS, or transformer nameplate.
- Note the Output Voltage: Single-phase systems typically output 120V or 240V; three-phase at 208V, 240V, or 480V.
- Select the Phase Type: Use the single-phase or three-phase formula based on your system.
- Calculate: The result is the maximum continuous current the device can supply — use it to select cables and protection devices.