kVA to Amps Converter
Conversion Formulas
Single Phase
I (A) = (S (kVA) × 1000) / (V (V) × PF)
Current in amps equals apparent power in kilovolt-amps multiplied by 1000, divided by voltage in volts multiplied by power factor.
Three Phase Line to Line
I (A) = (S (kVA) × 1000) / (√3 × VL-L (V) × PF)
Phase current equals apparent power multiplied by 1000, divided by square root of 3 times line-to-line voltage times power factor.
Three Phase Line to Neutral
I (A) = (S (kVA) × 1000) / (3 × VL-N (V) × PF)
Phase current equals apparent power multiplied by 1000, divided by 3 times line-to-neutral voltage times power factor.
Conversion Examples
Example 1: Converting 25 kVA to Amps (Single Phase)
Given: 25 kVA, 240V, Power Factor = 0.8
Calculation: I = (25 × 1000) / (240 × 0.8) = 25,000 / 192 = 130.21 A
Result: 130.21 Amps
Example 2: Converting 100 kVA to Amps (Three Phase)
Given: 100 kVA, 480V Line-to-Line, Power Factor = 0.9
Calculation: I = (100 × 1000) / (√3 × 480 × 0.9) = 100,000 / 748.67 = 133.56 A
Result: 133.56 Amps
Example 3: Converting 75 kVA to Amps (Single Phase, Unity Power Factor)
Given: 75 kVA, 120V, Power Factor = 1.0
Calculation: I = (75 × 1000) / (120 × 1.0) = 75,000 / 120 = 625 A
Result: 625 Amps
kVA to Amps Conversion Chart
| kVA | 120V (Single Phase) | 240V (Single Phase) | 480V (3-Phase) |
|---|---|---|---|
| 1 | 10.42 A | 5.21 A | 1.51 A |
| 5 | 52.08 A | 26.04 A | 7.53 A |
| 10 | 104.17 A | 52.08 A | 15.05 A |
| 15 | 156.25 A | 78.13 A | 22.58 A |
| 20 | 208.33 A | 104.17 A | 30.11 A |
| 25 | 260.42 A | 130.21 A | 37.64 A |
| 30 | 312.50 A | 156.25 A | 45.16 A |
| 45 | 468.75 A | 234.38 A | 67.74 A |
| 50 | 520.83 A | 260.42 A | 75.27 A |
| 75 | 781.25 A | 390.63 A | 112.90 A |
| 100 | 1,041.67 A | 520.83 A | 150.54 A |
| 150 | 1,562.50 A | 781.25 A | 225.81 A |
| 200 | 2,083.33 A | 1,041.67 A | 301.08 A |
| 300 | 3,125.00 A | 1,562.50 A | 451.62 A |
| 500 | 5,208.33 A | 2,604.17 A | 752.70 A |
*Assuming Power Factor of 0.8 for all calculations
Common Transformer Ratings
| Transformer Size | Single Phase (240V) | Three Phase (480V) |
|---|---|---|
| 5 kVA | 26.04 A | 7.53 A |
| 10 kVA | 52.08 A | 15.05 A |
| 15 kVA | 78.13 A | 22.58 A |
| 25 kVA | 130.21 A | 37.64 A |
| 37.5 kVA | 195.31 A | 56.45 A |
| 50 kVA | 260.42 A | 75.27 A |
| 75 kVA | 390.63 A | 112.90 A |
| 100 kVA | 520.83 A | 150.54 A |
| 150 kVA | 781.25 A | 225.81 A |
| 225 kVA | 1,171.88 A | 338.71 A |
| 300 kVA | 1,562.50 A | 451.62 A |
| 500 kVA | 2,604.17 A | 752.70 A |
Related Conversions
Frequently Asked Questions
What is kVA?
kVA stands for kilovolt-amperes, which is a unit of apparent power in electrical systems. It represents the total power flowing in an alternating current (AC) circuit, combining both real power (kW) and reactive power (kVAR). One kVA equals 1,000 volt-amperes.
How do I convert kVA to amps?
To convert kVA to amps, you need to know the voltage and power factor. For single-phase systems, divide the kVA value by voltage and power factor, then multiply by 1,000. For three-phase systems, you also need to account for the square root of 3 (approximately 1.732) or factor of 3, depending on whether you’re using line-to-line or line-to-neutral voltage.
What is power factor and why does it matter?
Power factor (PF) is the ratio between real power (kW) and apparent power (kVA), ranging from 0 to 1. It indicates how efficiently electrical power is being used. A power factor of 1.0 means all power is being used effectively, while lower values indicate some power is reactive. Most industrial equipment has a power factor between 0.7 and 0.9.
How many amps is a 50 kVA transformer?
A 50 kVA transformer can handle approximately 260.42 amps at 240V single-phase, or about 75.27 amps at 480V three-phase (line-to-line). The exact amperage depends on the voltage level and power factor. These calculations assume a typical power factor of 0.8.
What’s the difference between single-phase and three-phase?
Single-phase power uses a single alternating current waveform and is common in residential applications. Three-phase power uses three alternating currents offset by 120 degrees, providing more consistent power delivery and is typically used in commercial and industrial settings. Three-phase systems can deliver more power using smaller conductors.
Can I convert amps back to kVA?
Yes, you can convert amps back to kVA by reversing the formulas. For single-phase: kVA = (Amps × Volts × Power Factor) / 1,000. For three-phase line-to-line: kVA = (Amps × Volts × √3 × Power Factor) / 1,000. You need to know the current, voltage, and power factor for accurate conversion.
Why are my calculated amps higher than expected?
If calculated amperage seems high, check your power factor value. A lower power factor results in higher current draw for the same kVA rating. Also verify that you’re using the correct voltage and phase configuration. Equipment with poor power factor requires more current to deliver the same real power.
What voltage should I use for my calculation?
Use the actual operating voltage of your system. Common voltages include 120V, 240V, and 480V in North America. For three-phase systems, specify whether you’re measuring line-to-line voltage (between two phase conductors) or line-to-neutral voltage (between a phase conductor and neutral). Always verify your system’s actual voltage as it may vary.