kW to Volts Formulas
DCV = 1000 × P(kW) ÷ I(A)
Single-phase ACV = 1000 × P(kW) ÷ (I(A) × PF)
Three-phase AC, line-to-lineV(L-L) = 1000 × P(kW) ÷ (√3 × I(A) × PF)
Three-phase AC, line-to-neutralV(L-N) = 1000 × P(kW) ÷ (3 × I(A) × PF)
Reverse formulas (volts → kW)
DCP(kW) = V × I ÷ 1000
Single-phase ACP(kW) = V × I × PF ÷ 1000
Three-phase AC, line-to-lineP(kW) = √3 × V(L-L) × I × PF ÷ 1000
Three-phase AC, line-to-neutralP(kW) = 3 × V(L-N) × I × PF ÷ 1000
Common Use Cases
Generator sizing
Enter the load in kW and its rated current to see what supply voltage the numbers imply — a quick sanity check before matching a generator's voltage configuration (120/240 V single-phase or 208/480 V three-phase).
Motor nameplate checks
A motor nameplate lists kW (or hp), voltage, current and PF. Plug any three into the calculator and verify the fourth — mismatches usually mean the wrong phase mode (L-L vs L-N) was assumed.
Battery & solar DC systems
Use DC mode for 12 V / 24 V / 48 V battery banks, solar panel strings and inverters: voltage = 1000 × kW ÷ amps tells you whether a given load current fits your system voltage.
Transformer checks
For a transformer, enter the load in kW and the secondary current to verify the implied secondary voltage — a fast cross-check against the transformer's rated 208/400/480 V secondary.
Heating elements
Resistive heaters have PF = 1, so single-phase mode with the PF slider at 1.00 gives the exact element voltage for a known wattage and current.
Frequently Asked Questions
What is the formula to convert kW to volts?
There are four cases. DC: V = 1000 × P(kW) ÷ I(A). Single-phase AC: V = 1000 × P(kW) ÷ (I(A) × PF). Three-phase AC, line-to-line: V = 1000 × P(kW) ÷ (√3 × I(A) × PF). Three-phase AC, line-to-neutral: V = 1000 × P(kW) ÷ (3 × I(A) × PF). Example: 4 kW DC at 3 A gives 4000 ÷ 3 = 1333.33 V. You always need the current in amps — kilowatts alone do not determine voltage.
Can I convert kW to volts without knowing the amps?
No. Kilowatts measure power and volts measure electrical potential — they are different quantities, so no direct conversion exists. To find voltage from power you must also know the current in amps (and the power factor for AC). If you only know kW and want a plausible current, pick a standard voltage first (for example 230 V or 400 V) and solve for the current instead — this calculator's common-voltage chips do exactly that.
What is the difference between kW and volts?
Volts (V) measure electrical potential difference — the "pressure" pushing current through a circuit. Kilowatts (kW) measure real power — the rate at which electrical energy is actually consumed or produced. They are linked by current: in DC, P = V × I ÷ 1000. Apparent power in kVA is V × I ÷ 1000 without the power factor; real power in kW multiplies that by the power factor.
How many volts is 1 kW?
It depends on the current. At 10 A DC, 1 kW gives 1000 ÷ 10 = 100 V. At 4.17 A DC, 1 kW gives about 240 V. For single-phase AC at 10 A with power factor 1, 1 kW also gives 100 V; with power factor 0.8 it gives 125 V. There is no fixed answer — current (and power factor for AC) always decide.
How do I convert volts to kW?
Use the reverse tab on this page, which applies the inverse formulas. DC: P(kW) = V × I ÷ 1000. Single-phase AC: P(kW) = V × I × PF ÷ 1000. Three-phase line-to-line: P(kW) = √3 × V × I × PF ÷ 1000. Three-phase line-to-neutral: P(kW) = 3 × V × I × PF ÷ 1000. Example: 230 V single-phase at 10 A with PF 0.9 gives 230 × 10 × 0.9 ÷ 1000 = 2.07 kW.
What is the DC kW to volts formula?
V = 1000 × P(kW) ÷ I(A). Multiply kilowatts by 1000 to get watts, then divide by the current in amps. Example: a 1.5 kW (1500 W) DC load drawing 6.25 A gives 1500 ÷ 6.25 = 240 V. Power factor does not apply to DC, so the calculator hides the PF slider in DC mode.
What is the single-phase kW to volts formula?
V = 1000 × P(kW) ÷ (I(A) × PF). Divide 1000 × kW by the product of current and power factor. Example: 4 kW at 3.75 A with PF 0.8 gives 4000 ÷ (3.75 × 0.8) = 4000 ÷ 3 = 1333.33 V. Use PF = 1 for purely resistive loads (heaters, incandescent lamps); 0.8–0.9 is typical for induction motors.
What is the three-phase kW to volts formula?
For line-to-line voltage: V(L-L) = 1000 × P(kW) ÷ (√3 × I(A) × PF). For line-to-neutral voltage: V(L-N) = 1000 × P(kW) ÷ (3 × I(A) × PF). Example: 4 kW at 2.165 A with PF 0.8 gives 4000 ÷ (1.732 × 2.165 × 0.8) = 1333.37 V line-to-line. The two results differ by a factor of √3: V(L-L) = √3 × V(L-N).
What is the difference between line-to-line and line-to-neutral voltage?
In a three-phase system, line-to-line voltage is measured between any two phase conductors, while line-to-neutral voltage is measured between one phase and the neutral. They are related by V(L-L) = √3 × V(L-N) ≈ 1.732 × V(L-N). So a 400 V line-to-line system has about 230 V line-to-neutral. Pick the mode that matches how your voltage is specified.
What power factor should I use?
Power factor (PF) is the ratio of real power to apparent power, between 0 and 1. Use 1 for resistive loads such as heaters, kettles, and incandescent lighting. Use 0.8–0.9 for induction motors and most industrial equipment. Use the value on the equipment nameplate or datasheet when available. If you guess, 0.8 is the common default for motor loads — but a wrong PF directly skews the voltage result.
Is the result RMS or peak voltage?
RMS (root mean square). All AC mains voltages — 120 V, 230 V, 400 V — are specified as RMS line voltages, and these formulas produce RMS values. Peak voltage is higher by a factor of √2 (≈1.414), so 230 V RMS has a peak of about 325 V, but you rarely need peak values for power calculations.
Why is my result unrealistically high or low?
Four usual causes. (1) Current too small: voltage is inversely proportional to current, so 4 kW at 0.1 A gives 40,000 V — check that you entered load current, not a fuse rating. (2) Wrong phase mode: using line-to-line when your number is line-to-neutral (or vice versa) shifts the answer by √3. (3) Wrong power factor: PF below 1 raises the computed voltage. (4) Motor starting current: a motor draws 5–7× its running current at startup, so nameplate running current gives the running voltage, not the starting dip.
Can I use this for sizing a generator, solar array, or battery?
As a first estimate, yes: enter the load's kW and current to see what supply voltage the numbers imply, or use the reverse tab to get kW from a known voltage and current. But real sizing also needs surge/starting current, generator kVA rating (not just kW), inverter efficiency, and local wiring codes. Treat this calculator as a planning aid, not an engineering sign-off — a licensed electrician should verify anything you actually build or buy.
How accurate is this calculator?
The math is exact for the ideal formulas — every result on this page is verified against an independent Python oracle. Real circuits deviate: harmonics distort the PF assumption, long wire runs add voltage drop, and supply voltage fluctuates with grid load. Expect the calculator to be right about the formula and slightly optimistic about the real world; for critical work, measure with a proper meter.
How is this different from the amps-to-kW calculator?
They are inverse tools. The amps-to-kW calculator (nrtechstudio.com/amps-to-kw/) computes power from voltage and current: P = V × I (× PF, × √3). This calculator computes voltage from power and current: V = 1000 × P ÷ I (÷ PF, ÷ √3). If you know two of the three quantities (volts, amps, kW), pick the tool that solves for the one you don't know.
How is this different from a voltage unit converter or kW-to-joules?
Different quantities entirely. kW-to-joules converters deal with energy (power × time), not voltage — a kilowatt running for an hour is energy, not a voltage level. A voltage unit converter changes units of the same quantity (volts ↔ millivolts ↔ kilovolts). This tool solves for voltage from power and current using circuit laws. Related hubs: electrical-unit-converter for cross-unit conversion, voltage-converter for voltage units and voltage drop. Battery capacity in amp-hours times voltage gives watt-hours (Ah × V = Wh) — that is also energy storage, not voltage.