Amps to VA Calculator

Convert current to apparent power (Volt-Amps)

Current (Amps)

A

Voltage i

V

Phase Type i

Single Phase Three Phase

Apparent Power

0

Volt-Amps (VA)

Calculation Formula

VA = Amps (A) × Volts (V)

VA = √3 × Amps (A) × Volts (V)

VA (Volt-Amps) represents apparent power in an AC circuit, combining real power (Watts) and reactive power (VARs).

An Amps to VA (Volt-Amperes) Calculator converts electrical current (Amps, A) into apparent power (VA) for AC circuits. Unlike Watts (real power), VA accounts for total power (real + reactive), making it essential for sizing transformers, UPS systems, and circuit protection devices.

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Key Concepts

1. Amperes (A)

• Electric current flowing in a circuit.

• Measured with an ammeter.

2. Volts (V)

• Electrical potential difference (voltage).

• Common voltages:

  • Single-phase: 120V (US), 230V (EU)

  • Three-phase: 208V, 400V, 480V

3. Volt-Amperes (VA)

• Apparent power (combination of real and reactive power).

• 1 VA = 1 Volt × 1 Amp

• Used for sizing electrical equipment (UPS, transformers).

4. Power Factor (PF)

• Ratio of real power (W) to apparent power (VA).

• PF = 1 (resistive loads like heaters).

• PF < 1 (inductive loads like motors).

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Formulas for Amps to VA Conversion

1. Single-Phase AC Circuit

$$\text{VA}=I(A)\times V(V)$$

Example:

• Current = 10 A, Voltage = 120 V

• VA = 10 × 120 = 1200 VA

2. Three-Phase AC Circuit (Line-to-Line Voltage)

$$\text{VA}=\sqrt{3}\times I(A)\times V_{L-L}(V)$$

Example:

• Current = 20 A, Voltage = 400 V

• VA = 1.732 × 20 × 400 = 13,856 VA (≈13.86 kVA)

3. Three-Phase AC Circuit (Line-to-Neutral Voltage)

$$\text{VA}=3\times I(A)\times V_{L-N}(V)$$

Example:

• Current = 15 A, Voltage = 230 V (L-N)

• VA = 3 × 15 × 230 = 10,350 VA (≈10.35 kVA)

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How the Amps to VA Calculator Works

1. Input Parameters Required:

   • Current (A)

   • Voltage (V)

   • Phase Type (Single or Three-Phase)

   • For Three-Phase: Line-to-Line (L-L) or Line-to-Neutral (L-N) Voltage

2. Calculation Steps:

   • Select single-phase or three-phase.

   • Enter current (A) and voltage (V).

   • The calculator applies the correct formula and outputs VA.

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Example Calculations

Example 1: Single-Phase AC

• Current (I): 5 A

• Voltage (V): 230 V

• VA = 5 × 230 = 1,150 VA

Example 2: Three-Phase AC (Line-to-Line Voltage)

• Current (I): 25 A

• Voltage (V): 480 V

• VA = 1.732 × 25 × 480 = 20,784 VA (≈20.8 kVA)

Example 3: Three-Phase AC (Line-to-Neutral Voltage)

• Current (I): 12 A

• Voltage (V): 120 V (L-N)

• VA = 3 × 12 × 120 = 4,320 VA (≈4.32 kVA)

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Applications of Amps to VA Calculator

✔ UPS & Inverter Sizing – Ensures backup power capacity matches load.
✔ Transformer Selection – Prevents overloading in power distribution.
✔ Circuit Breaker & Fuse Ratings – Helps in selecting proper protection.
✔ Industrial Motor Loads – Determines power requirements for machinery.

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VA vs. Watts: Key Differences

Parameter	VA (Apparent Power)	Watts (Real Power)
Definition	Total power (real + reactive)	Actual usable power
Formula (Single-Phase)	$I\times V$	$I\times V\times PF$
Power Factor (PF) Effect	Not affected	Directly affected
Usage	Equipment sizing (UPS, transformers)	Energy billing, actual consumption

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Limitations

⚠ Assumes Balanced Load (3-Phase) – Unbalanced loads require per-phase calculation.
⚠ Does Not Include Harmonics – Non-linear loads (e.g., computers) may need derating.