Electrical

kVA to Amps Calculator

Convert apparent power in kilovolt-amperes (kVA) to load current in amps for single-phase and balanced three-phase US electrical systems.

Enter kVA and voltage, then choose the circuit. Three-phase calculations use line-to-line voltage.

Calculation and worked example reviewed 2026-11-12. See our calculation methodology.

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Electrical

Enter your measurements

US UNITS

Apparent power

kVA

Voltage

Circuit

Optional: Material Price ($ / unit)

YOUR ESTIMATE

62.5 A15 kVA at 240 V

Phase multiplier 1.

Use line-to-line volts for balanced three phase.

Formula and example

How this calculation works

This estimator converts your entered jobsite inputs (apparent power, voltage, circuit) into consistent US trade units, computes the exact geometric baseline first, and then applies any selected waste or order allowance so you can verify both numbers before purchasing materials.

How does the kva to amps calculator formula work?

Current (A) = kVA × 1,000 ÷ (voltage × phase multiplier); multiplier = 1 for single phase or √3 for balanced three phase.

(kVA to Amps Calculator)

where:

Apparent power – Entered in kVA (default reference: $15 kVA$ );
Voltage – Entered in V (default reference: $240 V$ );
Circuit – Entered in selected option (default reference: $single$ );

The formula

Inputs to result

Current (A) = kVA × 1,000 ÷ (voltage × phase multiplier); multiplier = 1 for single phase or √3 for balanced three phase.

Worked example

Check the math

A 15 kVA load at 240 V single phase draws 15,000 ÷ 240 = 62.5 A. At 480 V three phase it draws about 18.04 A.

Quick lookup chart

Transformer & Generator kVA to Full-Load Amps Reference

Apparent power conversion using I = kVA × 1,000 ÷ V (1Φ) and I = kVA × 1,000 ÷ (√3 × V) (3Φ).

Rating (kVA)	240V Single Phase	208V Three Phase	480V Three Phase
15 kVA	62.50 A	41.64 A	18.04 A
25 kVA	104.17 A	69.39 A	30.07 A
45 kVA	187.50 A	124.91 A	54.13 A
75 kVA	312.50 A	208.18 A	90.21 A

Limits and field checks

Before you use this result

kVA measures apparent power. This conversion does not size conductors, overcurrent devices or a transformer for starting, temperature and demand conditions.

Because kVA already represents apparent power (volts × amps), power factor is not included when converting kVA to line current.
Transformer primary and secondary overcurrent protection, feeder sizing, and tap rules must follow NEC Article 450 and Article 240.
Always verify whether a three-phase system is 208Y/120 V or 480Y/277 V and enter the line-to-line voltage.

Questions answered

Calculator FAQ

How do I convert three-phase kVA to amps?+

Multiply kVA by 1,000, then divide by square root of three times line-to-line voltage.

Do I need power factor?+

No. kVA is apparent power, so the kVA-to-current conversion does not require power factor.