What is the difference between kVA and kW?

kVA (kilovolt-amps) is apparent power — the total current × voltage product. kW (kilowatts) is real power — the portion that does useful work. The relationship is kW = kVA × Power Factor. A 10 kVA generator at PF 0.80 can deliver only 8 kW of real power. Always check whether equipment is rated in kVA or kW.

How do I size a generator using kVA and power factor?

Calculate total real power (kW) needed, then divide by the generator power factor to get the required kVA rating: kVA = kW ÷ PF. For 12 kW of load with PF 0.80: kVA = 12 ÷ 0.80 = 15 kVA minimum generator. Add 20–25% for startup surges from motors and compressors.

What is a good power factor?

A power factor above 0.95 is excellent. 0.85–0.95 is acceptable for most installations. Below 0.85, utilities may charge power factor penalties. Below 0.70 indicates significant reactive power waste. Power factor correction capacitors can improve PF to 0.95+ by compensating for inductive loads.

How do I convert VA to watts?

Multiply VA by the power factor: Watts = VA × PF. A 1,500 VA UPS at PF 0.70 delivers 1,050 watts of real power. Modern UPS units often list both VA and watt ratings. If only VA is listed, assume PF 0.60–0.70 for older units and PF 0.90+ for newer models.

Why do utilities charge for low power factor?

Low power factor means the utility must supply extra current that does no useful work, heating transformers and transmission lines without generating revenue. Industrial customers with PF below 0.85–0.90 may face penalty surcharges of 1–2% per 0.01 PF below the threshold. Correction capacitors pay for themselves quickly.

What is reactive power (kVAR)?

kVAR (kilovolt-amp reactive) is the reactive component of power — energy that oscillates between the source and inductive/capacitive loads without doing useful work. It combines with real power (kW) to form apparent power (kVA): kVA² = kW² + kVAR². Reducing kVAR through capacitor banks improves power factor.

Apparent power

Amps to Volt-Amps (VA) Calculator

VA = Amps x Volts

Free Amps to Volt-Amps Calculator — convert amperes to volt-amps for apparent power calculations. Includes DC, single-phase AC, and three-phase AC support. Essential for electrical engineering and power system design.

Live result 0 W Amps to watts

Conversion calculator

Circuit Type

Voltage Type

Current

Voltage (V)

Power Factor (PF)

Power (kW)

Power (W)

Common load presets

Recent calculations

AC power quality

Power triangle clarity

AC/DC single-phase formula-first page-specific visual

Amps to Volt-Amps (VA) Calculator Guide

Real vs apparent power

Watts, VA, kVA, and power factor shown as one relationship

These conversions depend on the difference between real and apparent power, so the power triangle makes the formula easier to trust.

Formula VA = Amps x Volts

Amps to Volt-Amps (VA) Calculator Real vs apparent power with real formula values and planning checkpoints.

Quick answer

Use this calculator to separate real watts from apparent power.

AC equipment can draw VA or kVA that is higher than usable watts. Power factor explains the difference and is critical for generators, UPS systems, motors, and transformers.

VA = Amps x Volts

Inputs to check before calculating

Use nameplate VA, kVA, or amperage where available.
Enter a realistic PF for motors, compressors, UPS systems, and generators.
Account for startup surge separately from running watts.
Compare real watts with equipment output ratings.

Example: 10 amps at 120 volts

At 120 volts, 10 amps equals 1,200 VA. For real watts, multiply apparent power by power factor.

Best use cases

UPS and transformer sizing
VA and kVA output
Single-phase apparent power
single-phase AC load planning with clear unit labels.

Common mistake to avoid

Do not treat kVA as kW unless the power factor is 1.00.

How to use the result

Use the result to avoid undersizing generators, UPS units, and AC power equipment.

Accuracy and safety note

Calculator output is a planning estimate. Final breaker sizing, wire gauge, derating, voltage-drop limits, equipment protection, and code compliance should be verified with manufacturer documentation and a qualified electrician or engineer.

For the broad formula, reference table, and breaker planning context, start with the main Amps to Watts Calculator.

Apparent power diagram

Current and Voltage to VA Flow

The calculator multiplies current by voltage to find apparent power. Apparent power helps size transformers, UPS systems, generators, and service panels before power factor is applied to real watts.

VA = A x V

Amps to Volt-Amps Formulas

DC / Single-Phase AC

VA = I Ã— V

Where:
I = Current (A)
V = Voltage (V)

Three-Phase AC (Line-to-Line)

VA = I Ã— V Ã— âˆš3

â‰ˆ I Ã— V Ã— 1.732

Three-Phase AC (Line-to-Neutral)

VA = I Ã— V Ã— 3

For line-to-neutral voltage

Calculation Examples

Single-Phase Circuit

15A at 120V:
15 Ã— 120 = 1800 VA
Typical for household circuit

Three-Phase Motor

10A at 230V line-to-line:
10 Ã— 230 Ã— 1.732 â‰ˆ 1732 VA
Small industrial motor

DC Power Supply

5A at 48V:
5 Ã— 48 = 240 VA
Network equipment power

Frequently Asked Questions

How do I convert amps to volt-amps?

For DC or single-phase AC: VA = Amps Ã— Volts. For three-phase: VA = Amps Ã— Volts Ã— âˆš3 (line-to-line) or VA = Amps Ã— Volts Ã— 3 (line-to-neutral).

What is the difference between VA and watts?

VA measures apparent power (total power drawn), watts measure real power (useful power). VA = Watts Ã· Power Factor.

When should I use VA instead of watts?

Use VA for sizing transformers, generators, UPS systems, and electrical service. These devices must handle the total apparent power, not just real power.

Related Industrial & 3-Phase Tools

Start with the main conversion tool

Need the general formula, conversion table, and breaker-safety context? Use the Amps to Watts Calculator as the main guide, then return to this specialized page for the exact voltage or circuit type.