Engineering calculators

kVA to Amps Calculator

Updated Jun 1, 2026 By Jehan Wadia
Configuration
Select your electrical system configuration.
Input Values
Result
Current
41.6667
Amps (A)
I (A) = (kVA × 1000) / V
Apparent Power10 kVA
Voltage240 V
ConfigurationSingle Phase
Calculated Current41.6667 A
Current vs. Voltage (at current kVA)

Introduction

This kVA to Amps calculator converts apparent power in kilovolt-amperes (kVA) to current in amperes (A). Just enter your kVA value and voltage, pick single phase or three phase, and the tool does the math for you. It works for both line-to-line and line-to-neutral three-phase systems. You also get a breakdown of the calculation and a chart that shows how current changes as voltage goes up or down.

Electricians, engineers, and students use this conversion to size wires, breakers, and other equipment. Knowing the full load amps from a kVA rating helps you make safe choices when working with transformers, generators, and electrical panels. Instead of doing the formula by hand, this calculator gives you a fast and accurate answer every time.

How to Use Our kVA to Amps Calculator

Enter your power and voltage values below, and this calculator will instantly convert kVA to amps for single phase or three phase systems.

Phase Type: Pick either Single Phase or Three Phase. This tells the calculator what kind of electrical system you have.

Voltage Type (Three Phase only): If you chose Three Phase, select whether your voltage is measured Line to Line or Line to Neutral.

Apparent Power (kVA): Type in your apparent power in kilovolt-amperes. This number must be greater than zero.

Voltage (Volts): Type in your voltage in volts. This number must be greater than zero.

Calculate: Press the Calculate button to get your result in amps. The tool also shows the formula used, a full breakdown of your inputs, and a chart of current vs. voltage.

Reset: Press the Reset button to clear all inputs and start over with the default values.

What Is a kVA to Amps Conversion?

kVA stands for kilovolt-amperes. It measures the apparent power in an electrical system. Amps (short for amperes) measure the current flowing through a wire. When you know the kVA and the voltage of a system, you can figure out how many amps are flowing. This is useful when sizing wires, breakers, or other electrical equipment. If you need to work with current and wattage instead, our Amps to Watts calculator and Watts to Amps calculator are helpful companion tools.

How to Convert kVA to Amps

The formula depends on whether your system is single phase or three phase.

Single Phase Formula

For a single phase system, the formula is:

Amps = (kVA × 1000) ÷ Volts

You multiply the kVA by 1,000 to convert it to volt-amperes (VA), then divide by the voltage.

Three Phase Formulas

For a three phase system using line-to-line voltage:

Amps = (kVA × 1000) ÷ (√3 × Volts)

The √3 (square root of 3) equals about 1.732. This factor accounts for the relationship between the three power lines. You can verify this constant with our square root calculator.

For a three phase system using line-to-neutral voltage:

Amps = (kVA × 1000) ÷ (3 × Volts)

Here you multiply the voltage by 3 instead of √3 because line-to-neutral voltage is already lower than line-to-line voltage.

When You Need This Conversion

Transformers, generators, and UPS systems are often rated in kVA. However, wire sizes, fuses, and circuit breakers are rated in amps. Converting kVA to amps helps you pick the right parts for your electrical setup. For example, if a transformer is rated at 50 kVA and runs at 240 volts single phase, you can calculate that it delivers about 208.3 amps. That tells you what size wire and breaker you need. Our wire size calculator can help you select the proper conductor, and the voltage drop calculator lets you verify that your wire runs won't lose too much voltage over distance.

When sizing a backup generator for a building, the generator sizing calculator pairs well with this tool to ensure your generator's kVA rating provides enough amperage for the connected loads. For related electrical work like planning conduit runs, check out the conduit fill calculator.

kVA vs. kW

kVA and kW are not the same thing. kW (kilowatts) measures real power — the power that actually does work. kVA measures apparent power, which includes both real power and reactive power. In a purely resistive load like a heater, kVA equals kW. In systems with motors or other inductive loads, kVA is higher than kW. The ratio between them is called the power factor. For a deeper understanding of electrical relationships, our Ohm's Law calculator covers the foundational connection between voltage, current, and resistance, while the power calculator helps with general power computations. If you're working with resistive circuits, the parallel resistor calculator and voltage divider calculator are also useful references. You can also explore the Amp calculator for other methods of determining current in a circuit.


Frequently asked questions

What does kVA mean?

kVA stands for kilovolt-amperes. It is a unit that measures apparent power in an electrical system. One kVA equals 1,000 volt-amperes. Transformers, generators, and UPS systems are commonly rated in kVA.

Why do I need to multiply kVA by 1000 in the formula?

The "k" in kVA stands for "kilo," which means 1,000. Multiplying by 1,000 converts kilovolt-amperes into volt-amperes (VA). This puts the power in the same scale as volts and amps so the division gives you the correct current.

What is the square root of 3 and why is it used in three phase calculations?

The square root of 3 is approximately 1.732. It appears in three phase formulas because the three power lines are spaced 120 degrees apart. This geometric relationship creates a factor of √3 between line-to-line voltage and the current flowing through each phase.

When should I use line-to-line voltage vs. line-to-neutral voltage?

Use line-to-line voltage when you measure voltage between any two of the three phase wires. Use line-to-neutral voltage when you measure voltage between one phase wire and the neutral wire. Your equipment nameplate or meter reading will tell you which one you have.

Can I use this calculator for a 208V three phase system?

Yes. Enter 208 in the voltage field, select Three Phase, and choose Line to Line. The calculator will use the √3 formula to give you the correct amps.

Can I use this calculator for a 480V three phase system?

Yes. Enter 480 as the voltage, select Three Phase, and pick Line to Line. The tool will divide (kVA × 1000) by (1.732 × 480) to give you the current in amps.

What is the difference between single phase and three phase power?

Single phase uses one AC waveform delivered over two wires (one hot, one neutral). Three phase uses three AC waveforms offset by 120 degrees, delivered over three or four wires. Three phase is more efficient for large loads and is common in commercial and industrial buildings.

Does this calculator account for power factor?

No. This calculator converts apparent power (kVA) to amps. Power factor relates kVA to real power (kW). Since kVA already includes the effect of power factor, you do not need it to find amps from kVA.

How do I convert amps back to kVA?

Reverse the formula. For single phase: kVA = (Amps × Volts) ÷ 1000. For three phase line-to-line: kVA = (Amps × Volts × 1.732) ÷ 1000. For three phase line-to-neutral: kVA = (Amps × Volts × 3) ÷ 1000.

What happens if I enter zero for voltage?

The calculator will show an error message. Voltage must be greater than zero because the formula divides by voltage. Dividing by zero is not possible and would give no meaningful result.

How many amps is a 75 kVA transformer at 480V three phase?

Using the line-to-line formula: Amps = (75 × 1000) ÷ (1.732 × 480) = 75,000 ÷ 831.36 ≈ 90.21 amps. You can enter these values into the calculator to verify.

Is the result from this calculator the per-phase current or total current?

For a balanced three phase system, the result is the per-phase line current, which is the current flowing through each of the three wires. This is the value you use to size wires and breakers for each phase.

What does the chart on the calculator show?

The chart plots current (amps) vs. voltage while holding your kVA value constant. It shows that as voltage increases, current decreases, and vice versa. An orange dot marks your specific input values on the curve.

Can I use this calculator for DC circuits?

No. kVA is a unit for AC (alternating current) systems. DC circuits do not have apparent power in the same way. For DC, simply use Amps = Watts ÷ Volts.

Why is the current higher at lower voltages for the same kVA?

Power equals voltage times current. If the power (kVA) stays the same but voltage goes down, the current must go up to deliver the same amount of power. This is why low-voltage systems need thicker wires.