Engineering calculators

Amps to kVA Calculator

Updated Jun 6, 2026 By Jehan Wadia
Configuration
Electrical Values
Enter the current in amperes.
Enter the voltage in volts.
Apparent Power Result
Apparent Power (Single Phase)
0.00 kVA
Formula used: S(kVA) = (I × V) / 1000
Current (I)50 A
Voltage (V)230 V
Apparent Power11.50 kVA

Introduction

This Amps to kVA calculator helps you convert electric current in amperes (A) to apparent power in kilovolt-amps (kVA). All you need to do is enter the current and voltage, pick your phase type, and the tool does the math for you right away. It works for both single phase and three phase systems, including line-to-line and line-to-neutral voltage setups.

Knowing the apparent power in kVA is important when you size generators, transformers, or other electrical equipment. The formulas are simple. For single phase, you multiply amps by volts and divide by 1,000. For three phase with line-to-line voltage, you multiply amps by volts by √3, then divide by 1,000. For three phase with line-to-neutral voltage, you multiply amps by volts by 3, then divide by 1,000. This calculator uses those exact formulas and shows you a full breakdown of each step so you can check the work yourself. If you need to do the reverse conversion, our kVA to Amps calculator handles that.

How to Use Our Amps to kVA Calculator

Enter your current and voltage values below, and this calculator will instantly give you the apparent power in kilovolt-amps (kVA).

Phase Type: Pick either Single Phase or Three Phase. Most homes use single phase. Most large machines and buildings use three phase. If you need to calculate full three-phase power including power factor, try our 3 Phase Power calculator.

Voltage Type (Three Phase only): If you chose three phase, select Line-to-Line or Line-to-Neutral. Line-to-Line is measured between two power lines. Line-to-Neutral is measured from one line to the neutral wire.

Current (A): Type in the current in amps. You can find this number on your device's nameplate or from a clamp meter reading. If you need to determine the current from other values first, our Amp calculator can help.

Voltage (V): Type in the voltage in volts. Common values are 120 V, 208 V, 230 V, 240 V, 277 V, and 480 V. You can verify voltage relationships across circuits using our Voltage Divider calculator.

Calculate: Press the Calculate button to see your result. The calculator shows the apparent power in kVA along with the formula and a full breakdown of the math.

Amps to kVA Conversion Explained

This calculator converts amps (A) to kilovolt-amps (kVA). Amps measure how much electric current flows through a wire. kVA measures apparent power, which is the total power a device or circuit uses. You need to know both the current in amps and the voltage in volts to find the apparent power in kVA.

How the Conversion Works

For single-phase circuits, you multiply amps by volts, then divide by 1,000. This gives you the apparent power in kVA. The formula is: kVA = (Amps × Volts) / 1,000.

For three-phase circuits, the math changes depending on how voltage is measured. If you use line-to-line voltage, you multiply amps by volts by √3 (about 1.732), then divide by 1,000. If you use line-to-neutral voltage, you multiply amps by volts by 3, then divide by 1,000.

When You Need This Conversion

Electricians, engineers, and technicians use this conversion when sizing generators, transformers, and electrical panels. Knowing the kVA rating helps you pick equipment that can handle the electrical load safely. For example, if a building draws 100 amps at 240 volts on a single-phase system, it needs at least 24 kVA of capacity. Our Generator Sizing calculator can help you determine the right generator for your load requirements.

kVA vs. kW

kVA and kW are not the same thing. kVA is apparent power, while kW is real power — the power that actually does useful work. The difference between them depends on the power factor, which shows how efficiently a circuit uses electricity. In a perfect system, kVA and kW are equal. In real systems, kVA is always equal to or greater than kW. You can explore the relationship between amps and watts using our Amps to Watts calculator, or convert in the other direction with our Watts to Amps calculator. For a deeper understanding of electrical fundamentals like voltage, current, resistance, and power, our Ohm's Law calculator is a great resource. If you're also checking wire capacity and voltage loss over long cable runs, our Voltage Drop calculator is essential for safe circuit design.


Frequently asked questions

What is kVA?

kVA stands for kilovolt-amps. It measures apparent power in an electrical circuit. Apparent power is the total power supplied to a circuit, including both the power that does useful work and the power that is lost. One kVA equals 1,000 volt-amps.

Why do I need both amps and volts to find kVA?

Amps alone only tell you how much current flows. You need voltage too because power depends on both current and voltage. Multiplying amps by volts gives you volt-amps. Dividing by 1,000 converts that to kVA.

What does √3 mean in the three-phase formula?

√3 is the square root of 3, which equals about 1.732. It appears in three-phase calculations because three-phase power uses three separate voltage waves spaced 120 degrees apart. This spacing creates a √3 relationship between line-to-line and line-to-neutral voltages.

How do I know if my system is single phase or three phase?

Most homes use single phase power. You usually have two hot wires and one neutral wire. Three phase power is used in factories, large buildings, and commercial spaces. You will have three hot wires. Check your electrical panel or ask your power company if you are not sure.

What is the difference between line-to-line and line-to-neutral voltage?

Line-to-line voltage is measured between any two of the three hot wires in a three-phase system. Line-to-neutral voltage is measured from one hot wire to the neutral wire. Line-to-line voltage is always higher than line-to-neutral voltage by a factor of √3.

Should I use line-to-line or line-to-neutral for my calculation?

Use whichever voltage you have measured or know. If you measured voltage between two power lines, pick line-to-line. If you measured from a power line to neutral, pick line-to-neutral. Both give the same kVA result when you use the correct formula.

Can I use this calculator for DC circuits?

Not directly. This calculator is designed for AC circuits. DC circuits do not have phases or apparent power in the same way. For DC, simply multiply amps by volts and divide by 1,000 to get kW, since there is no reactive power in DC.

What is a typical voltage value I should enter?

Common voltages depend on your country and system. In the US, typical values are 120 V, 208 V, 240 V, 277 V, and 480 V. In many other countries, 230 V and 400 V are standard. Check your equipment nameplate or electrical panel for the exact voltage.

Where do I find the amp rating of my equipment?

Look at the nameplate on your device. It is usually a metal or plastic label on the back or side. It lists the rated current in amps (A). You can also use a clamp meter to measure the actual current while the device is running.

How do I convert the kVA result to kW?

Multiply kVA by the power factor. The formula is: kW = kVA × power factor. Power factor is a number between 0 and 1. For most motors it is around 0.8 to 0.9. For resistive loads like heaters it is close to 1.0.

What if my current value is in milliamps?

Divide your milliamps by 1,000 to get amps, then enter that number. For example, 500 milliamps equals 0.5 amps. Type 0.5 into the current field.

Can I use this calculator to size a transformer?

Yes. Find the total amps your loads will draw and the voltage of your system. Enter those values to get the kVA. Pick a transformer with a kVA rating equal to or higher than your result. It is good practice to add a safety margin of 20% to 25%.

Why is my kVA result different from the wattage on my device?

The wattage on your device shows real power (kW), not apparent power (kVA). Apparent power is always equal to or greater than real power. The difference is caused by the power factor. Only purely resistive loads like heaters have kVA equal to kW.

Does this calculator account for power factor?

No. This calculator finds apparent power in kVA, which does not require power factor. Power factor is only needed when you want to convert between kVA and kW. The amps-to-kVA conversion uses only current and voltage.