Volt-Ampere to Kilovolt-Ampere Converter (VA to kVA & MVA

Volt-Amperes (VA), Kilovolt-Amperes (kVA) & 3-Phase Current Metrology

Apparent power in AC systems is scaled by decimal metric prefixes:

• **

• Exact SI Metric Prefix Relationships**:

S_kVA = S_VA1,000, S_MVA = S_kVA1,000 = S_VA1,000,000

1 kVA = 1,000 VA, 1 MVA = 1,000 kVA = 1,000,000 VA

• **

• Full-Load Line Current Formulas**:

• Single-Phase (1Φ):

I_Amps = S_VAV_Line-to-Neutral = S_kVA × 1,000V

• Three-Phase (3Φ Balanced):

I_Amps = S_VA√(3) × V_Line-to-Line = S_kVA × 1,0001.73205 × V

• **

• Standard Commercial Transformer Sizes (kVA)**:

• Single-Phase: 15 kVA, 25 kVA, 37.5 kVA, 50 kVA, 75 kVA, 100 kVA

• Three-Phase: 30 kVA, 45 kVA, 75 kVA, 112.5 kVA, 150 kVA, 225 kVA, 300 kVA, 500 kVA, 750 kVA, 1,000 kVA

How to Use This Calculator

Enter your Apparent Power Magnitude (e.g. 75000 in S), From Unit — choose from Volt-Amperes (VA - Base SI), Kilovolt-Amperes (kVA = 1,000 VA), Megavolt-Amperes (MVA = 1,000,000 VA), Operating Voltage (V_RMS) (e.g. 480 in V), Electrical Phase Configuration — choose from Three-Phase (3Φ - Line-to-Line: S = √3 × V × I), Single-Phase (1Φ - Line-to-Neutral: S = V × I), and Transformer & Power System Benchmark — choose from Custom Power & Voltage, 1,500 VA Server UPS (120V 1Φ) → 1.50 kVA (12.50 A), 24,000 VA Residential Service (240V 1Φ) → 24.0 kVA (100.0 A). Results update instantly as you type — adjust any value to compare scenarios.

The Formula

Formula Reference: Volt-Ampere to Kilovolt-Ampere Converter (VA to kVA & MVA)

Input variables:

apparentPowerMagnitudeInput — Apparent Power Magnitude

sourceApparentUnitSelect — From Unit

circuitVoltageVoltsInput — Operating Voltage (V_RMS)

circuitPhaseConfigSelect — Electrical Phase Configuration

Computed outputs:

apparentPowerKva — Apparent Power in Kilovolt-Amperes (kVA)

apparentPowerVa — Apparent Power in Volt-Amperes (VA)

apparentPowerMva — Apparent Power in Megavolt-Amperes (MVA)

fullLoadCurrentAmps — Full-Load Line Current (Amperes / A)

realPowerAtEightyPercentPf — Real Work Power (kW at standard 0.80 PF)

Mathematical relationships extracted from calculation logic:

kva = va / 1000.0

mva = va / 1e6

currentAmps = safeDiv(va, Math.sqrt(3.0) * vVal)

kw80 = kva * 0.80

Reference constants:

va = 75000.0

Standard: NIST Handbook 44 and BIPM SI unit definitions

Worked Example

An electrical contractor sizing the primary feeder breaker for a 75,000 VA (75 kVA) 480V 3-phase transformer calculates full-load current as I = 75,000 / (√(3) × 480) = 90.21 A, specifying 100A or 125A thermal-magnetic circuit breakers.

Understanding Your Result

Unit conversion precision: round to the same number of significant figures as your original measurement. Converting 6 feet to meters gives 1.8288 m — but if your measurement was approximate (±1 inch), expressing more than 2 decimal places is false precision. For international trade and technical specifications, SI units (meters, kilograms, liters) are the standard. US customary units (feet, pounds, gallons) differ from Imperial UK units: 1 US gallon = 3.785 L vs. 1 UK gallon = 4.546 L.