To determine the apparent power in kilovolt-amps, input the phase number, current in amps,
voltage in volts, and then click the Calculate button. This will provide you with the desired result.
⚠️ Please enter valid positive values for Amps and Volts.
The Amps to kVA Calculator on CheckBillOnline.com
is a free, instant tool that converts electrical current (amperes) and voltage (volts) into apparent power
expressed in kilovolt-amperes (kVA). Whether you are an electrician sizing a transformer, a homeowner
checking your generator capacity, or an engineer planning a power distribution system, this calculator
saves time and eliminates manual math errors.
Apparent power (kVA) is the total power delivered by an electrical source to a circuit, combining both
active power (watts) and reactive power (VAR). Unlike kilowatts, kVA does not account for the power factor,
making it a critical figure when selecting transformers, UPS units, generators, and switchgear. Knowing
the kVA rating ensures you never overload equipment, helping you avoid costly downtime and safety hazards.
The calculator supports three modes: Single-phase systems (common in homes and small
businesses), Three-phase Line-to-Line (industrial machinery), and Three-phase Line-to-Neutral (data centres,
large commercial installations). Simply select your phase type, enter the current in amps and the voltage
in volts, and click Calculate — the result appears instantly in kVA.
Formulas for Converting Amps to kVA
Single-Phase Formula
Apparent power S in kilovolt-amps equals current I in amps multiplied by voltage V in volts, divided by 1000:
S(kVA) = I(A) × V(V) / 1000
Example: A 230 V circuit drawing 50 A → S = 50 × 230 / 1000 = 11.5 kVA
Three-Phase – Line to Line Voltage
S(kVA) = √3 × I(A) × VL-L(V) / 1000
Example: 20 A at 230 V L-L → S = 1.732 × 20 × 230 / 1000 = 7.967 kVA
Three-Phase – Line to Neutral Voltage
S(kVA) = 3 × I(A) × VL-N(V) / 1000
Example: 100 A at 400 V L-N → S = 3 × 100 × 400 / 1000 = 120 kVA
How to Use This Calculator
Select Phase Type — Choose Single phase, Three-phase Line-to-Line, or Three-phase Line-to-Neutral from the dropdown menu depending on your electrical system.
Enter Amps — Type the current value in amperes. This is the rated or measured current flowing through the circuit.
Enter Volts — Input the supply voltage in volts. For single-phase use line voltage; for three-phase specify either line-to-line or line-to-neutral as selected.
Click Calculate — Press the green Calculate button. The apparent power result will appear instantly below the buttons in kVA.
Reset if Needed — Click the red Reset button to clear all fields and start a new calculation.
Amps to kVA Conversion Table
Here's a table that shows the conversion of amps to kVA for different voltages (single-phase):
Apparent Power in kVA
208 V
240 V
480 V
Note: Values are approximate and may vary slightly depending on power factor and equipment efficiency.
Frequently Asked Questions (FAQs)
What is the difference between kVA and kW? ⌄
kVA (kilovolt-amperes) is apparent power — the total electrical load delivered. kW (kilowatts) is real or active power — the actual work done. The relationship is: kW = kVA × Power Factor. Most equipment has a power factor between 0.8 and 1.0. Transformers and generators are rated in kVA because they must handle the full apparent power regardless of the load's power factor.
Why do I need to convert amps to kVA? ⌄
Transformers, UPS systems, generators, and switchgear are all rated in kVA. When you know the current (amps) your equipment draws and the supply voltage, converting to kVA tells you the minimum capacity of the electrical equipment you need to install or purchase. It prevents undersizing which causes overloads, tripped breakers, and equipment damage.
Which voltage do I enter for three-phase calculations? ⌄
It depends on what measurement you have. If you measured voltage between two live conductors (line cables), that is Line-to-Line voltage — select the corresponding option. If you measured between one live conductor and the neutral wire, that is Line-to-Neutral voltage. In a typical 415 V (L-L) three-phase system, the Line-to-Neutral voltage is approximately 240 V.
Can I use this calculator for generator sizing? ⌄
Yes. To size a generator, add up the amps of all the loads it must supply, note the supply voltage, and use this calculator to find the required kVA. Add a safety margin of 20–25% above the calculated kVA to handle start-up surges from motors and compressors. Always consult a licensed electrician for final generator sizing and installation.
Is kVA the same as kVAR? ⌄
No. kVAR (kilovolt-amperes reactive) is the reactive component of electrical power, caused by inductive or capacitive loads like motors and transformers. kVA is the vector sum of kW (real power) and kVAR (reactive power): kVA² = kW² + kVAR². This calculator computes kVA only. Power factor correction capacitors reduce kVAR and improve the kW-to-kVA ratio.
What is a typical household voltage in Pakistan? ⌄
In Pakistan, the standard single-phase household supply is 220–230 V at 50 Hz. Three-phase industrial supply is typically 380–415 V line-to-line (220–240 V line-to-neutral). For most home calculations using this tool, enter 220 or 230 in the volts field with Single phase selected.
How do I convert kVA back to amps? ⌄
For single phase: I (A) = kVA × 1000 / V. For three-phase L-L: I (A) = kVA × 1000 / (√3 × V). For three-phase L-N: I (A) = kVA × 1000 / (3 × V). You can use our companion kVA to Amps Calculator for this reverse conversion.
The CheckBillOnline team consists of electrical engineers, energy consultants, and web developers
dedicated to building accurate, easy-to-use utility and electrical calculators. Our tools are designed
for homeowners, engineers, and businesses in Pakistan and across South Asia who need reliable
conversions and bill estimates without complex software. All formulas are verified against IEC and
IEEE standards. Have feedback? Contact us through our website.
CheckBillOnline is your one-stop digital platform for instantly checking and managing all your bills – electricity, gas, water, and internet – from a single convenient location.
