kVA to Amps Calculator

Common kVA to amps searches

Pre-calculated line current for typical queries (balanced load). Three-phase tables cover 400 V, 208 V, and 480 V line-to-line; single-phase uses 230 V. Open a row to load the same inputs in the calculator above.

Reverse lookup: amps to kVA (3-phase, balanced)

When you know the line current (A) and line-to-line voltage, use kVA = √3 × V × I ÷ 1000. Common supply ratings:

400 V three-phase (line-to-line)

230 V single-phase

208 V three-phase (line-to-line)

480 V three-phase (line-to-line)

Formulas and √3 / line-to-line basis: see How to Calculate Amps from kVA. Table currents rounded to two decimals.

When is kVA to amps conversion used?

Users already hold kVA and a nominal voltage and need a line current (A) to move sizing forward. Typical buckets:

• Branch design — protection, conductors, and feeder drop follow the same continuous current; use the ordered steps in Typical engineering workflow (links there).
• UPS / PDU / panel roll-ups — rough AC current from kVA and nominal voltage before vendor-specific derating.
• Transformer or generator interfaces — sanity-check secondary or setpoint current (transformer, generator).

Concrete delivery stories (motors, UPS, switchboards) are in Typical scenarios. This tool stays balanced, RMS, sinusoidal—harmonics and unbalance need separate studies.

Typical engineering workflow

The query kVA to amps usually sits in the middle of a sizing story. One coherent chain (balanced AC, RMS basis) looks like this:

1. Load / demand — establish real power or a known kVA envelope from schedules, motors, or vendor plates.
2. kW → kVA (when needed) — if you only have kW and power factor, use kW to kVA before current.
3. kVA → amps — this page: pick phase and the correct voltage basis (three-phase L-L).
4. Protection — breaker sizing for overcurrent frames and settings (coordination is a separate study).
5. Conductors — cable sizing and voltage drop with length and installation method.
6. Source equipment — when kVA changes upstream, revisit transformer or generator envelopes.

For P/Q/S from V–I–PF use 3-phase power. Switch single- or three-phase with the phase selector on this page.

Typical scenarios (where kVA→A shows up)

Delivery contexts where kVA is the hand-off value and A unlocks the next artifact (workflow order lives in Typical engineering workflow).

• Motor groups and MCC buckets — schedules in kVA → line A for starter/bucket catalog checks.
• UPS or PDU output planning — nameplate kVA + nominal voltage → first-pass branch current (vendor curves still authoritative).
• Transformer secondary reviews — secondary kVA + L-L → line current before tap or switchgear revisions.
• Panel and switchboard summaries — lumped kVA → bus current story; diversity/unbalance stay in the panel study.

How to Calculate Amps from kVA

Single-phase vs three-phase

Single-phase: use the working voltage you apply in the formula (often line-to-neutral or line-to-line depending on how the load is defined). Here we use one voltage field V as the divisor:

I_(A) = S_(kVA) × 1000 / V_(V)

Balanced three-phase: use line-to-line RMS voltage V_L-L. Total apparent power S is split across three lines, which introduces the factor √3:

I_L = S_(kVA) × 1000 / (√3 × V_L-L) ≈ S_(kVA) × 1000 / (1.73205 × V_L-L)

The √3 term reflects balanced three-phase geometry, not a missing PF. Starting from kW → use kW to kVA first; here you already enter kVA, so PF is not required for this step.

Workflow: Typical engineering workflow (kW → kVA → amps → breaker → cable).

Worked examples

Each line shows substitution into the same formulas the calculator uses (rounded to two decimals).

1. 50 kVA, 400 V, three-phase (line-to-line)
   I = 50 × 1000 / (1.73205 × 400) = 50 000 / 692.82 ≈ 72.17 A.
   Typical next step (education only): classroom bracketing often jumps to the next standard molded-case frame above continuous current—for example 80 A or 100 A frames are common talking points for ~72 A. Confirm trip curve, terminal temperature, and applicable code before procurement.
2. 10 kVA, 230 V, single-phase
   I = 10 × 1000 / 230 = 10 000 / 230 ≈ 43.48 A.
   Often paired with branch-circuit protection and conductor ampacity checks.
3. 200 kVA, 480 V, three-phase (line-to-line)
   I = 200 × 1000 / (1.73205 × 480) = 200 000 / 831.38 ≈ 240.56 A.
   Typical context: North American 480 V plant buses—continue to breaker sizing and upstream gear coordination.
4. 1000 kVA transformer, 480 V three-phase (line-to-line)
   I = 1000 × 1000 / (1.73205 × 480) = 1 000 000 / 831.38 ≈ 1202.81 A.
   This is current on the 480 V side only—not a universal “1000 kVA = 1202.81 A” value for every winding.

Common line voltages (pick the right basis)

The same kVA produces different line current as voltage changes. Typical service levels engineers pair with this calculator:

• 400 V L-L (three-phase) — common industrial/commercial in much of Europe; aligns with many IEC-style tables.
• 415 V L-L — still seen on older or site-specific plant; treat it as its own line-to-line basis in the formula.
• 480 V L-L (three-phase) — widely used in North American facilities and motor buses.
• 208 V / 230 V (single-phase) — 208 V often derives from 120/208 Wye feeders; 230 V is a common European single-phase service reference.

Select the voltage in the calculator that matches your nominal system; confirm whether the value on the drawing is line-to-line or line-to-neutral before substituting.

After you have amps: frame bracketing (education only)

Many users convert kVA to amps to discuss the next commercial overcurrent frame. The table below is not code, trip curves, or manufacturer data—it only illustrates how examples often round up to common frame sizes.

Continue in the breaker size calculator with continuous current, conductor protection, and utility constraints.

Frequently Asked Questions

For detailed guides and examples, see our 3 Phase Power Formula & Examples, kW to kVA Formula Guide, Power factor formula, and 3 Phase Transformer Calculation Formulas.

Advanced Result Explanation and Next Step

Quick outbound map (assumptions match the result note above).

Upstream: kW to kVA · 3-phase power · Power calculator hub

Downstream: Breaker size · Cable size · Voltage drop · Transformer sizing · Generator sizing

Phase selection: use the calculator phase selector for single- or three-phase on this page.