Free tool
kW to Amps Calculator
Kilowatts times a thousand, divided by volts and power factor — and by 1.732 on three-phase. The one thing a plain converter never asks is whether the kW is going in or coming out, and for a motor that is the whole difference.
kW × 1,000 ÷ (volts × power factor)
amps = kW × 1,000 ÷ (volts × power factor) on single-phase, and ÷ (volts × 1.732 × power factor) on three-phase using the line-to-line voltage. 10 kW at 240 V is 41.7 A; 50 kW at 480 V three-phase and 0.9 power factor is 66.8 A per line.
A motor's kW is its shaft output, so its input is larger by the efficiency: a 7.5 kW, 90 percent efficient motor draws about 12.3 A at 460 V three-phase, not the 11.1 A a plain conversion gives. For the motor circuit itself, the NEC Article 430 tables govern.
The rating
Enter 7,600 W as 7.6.
The supply voltage.
1.00 for a resistive heater; about 0.85 for a loaded motor. A nameplate figure beats any preset.
The answer
Current drawn
41.7 A
10.00 kW × 1,000 ÷ (240 V × 1.00 PF)
Apparent power: 10.00 kVA, equal to the kW at a power factor of 1.
What this does not tell you
A breaker or wire size. Conductor ampacity depends on material, insulation and terminal temperature ratings, raceway fill and ambient temperature; equipment with its own installation instructions — an EV charger, a heat pump — states its required circuit on the nameplate, and that governs.
What size generator a building needs. A generator's kW converts to the current it can deliver; the load it has to carry, including motor starting, is a separate calculation.
Informational use only, please verify before you rely on it
This reproduces standard conversion arithmetic from real power in kW to current for DC, single-phase and three-phase systems, with power factor and, for motors, efficiency applied. It is a preparation aid, not a determination and not a design. It does not size conductors or overcurrent protection; motor branch circuits are sized from the NEC 430.248 and 430.250 full-load current tables under 430.6(A)(1), not from this figure; and it does not size a generator for a building's load. Confirm against the equipment nameplate and installation instructions and with the authority having jurisdiction.
This tool is provided for general informational and educational purposes only. Its output is an illustrative estimate generated from the values you enter and from general assumptions that will not match every deal, market, lender, or homeowner. It is not tax, legal, accounting, financial, or professional advice, and it is not a quote, an offer, a credit decision, or a guarantee of pricing, approval, timing, savings, or eligibility.
You are solely responsible for independently confirming all information presented here including any figures, rates, fees, margins, timelines, tax treatment, and federal, state, local, or utility incentives, with the applicable lender, authority having jurisdiction, and your own qualified tax, legal, and financial advisors before acting on it, relying on it, or presenting it to a homeowner or any third party. Incentive programs, lender terms, and permitting requirements change frequently and vary by jurisdiction.
Seamless Home is not a tax advisor, law firm, lender, or licensed installing contractor, and makes no representation or warranty as to the accuracy, completeness, or currency of the information produced by this tool. To the fullest extent permitted by law, Seamless Home accepts no liability for any decision made or action taken in reliance on it.
Where a kW figure turns up on a project
On residential work the kW ratings that get converted most are the inverter, the battery, the EV charger and the heat strips — and every one of them is a continuous load. An inverter's output current is what it backfeeds into the panel, which is where the solar backfeed capacity calculator takes over. A battery's kW against the circuits it has to carry is the question the critical load panel planner works through.
The power factor input is the one people skip. What power factor is explains why kW and kVA differ and why a utility cares about the gap. When the rating is already in kVA — a transformer, most commercial generators — use the kVA to amps calculator instead, which applies no power factor at all; for a rating in watts, the watts to amps calculator carries the result through to a standard breaker size.
Frequently Asked Questions
How do you convert kW to amps?+
Multiply kW by 1,000 to get watts, then divide by the voltage — and by the power factor on AC, and by the square root of three as well on three-phase. 10 kW at 240 V single-phase and a power factor of 1 is 41.7 A. 50 kW at 480 V three-phase and a power factor of 0.9 is 66.8 A per line. On DC there is no power factor: 5 kW from a 48 V battery bank is 104.2 A.
How many amps is a 7.6 kW inverter or an 11.5 kW EV charger?+
At 240 V, a 7.6 kW inverter delivers 31.7 A at full output and an 11.5 kW charger draws 47.9 A — which is a 48 A charger. Both are continuous loads, so the circuit is sized at 125 percent: 39.6 A and 59.9 A, which is why these usually sit on 40 A and 60 A circuits. The nameplate or installation instructions state the required circuit, and they govern.
Why does a motor need an efficiency figure?+
Because a motor's kW rating is mechanical power at the shaft, not electrical power at the terminals. The motor draws its output plus its losses, so its input is the output divided by the efficiency. A 7.5 kW three-phase motor at 460 V, 90 percent efficient with a power factor of 0.85, draws about 12.3 A; reading its kW as electrical would give about 11.1 A. A generator's or an inverter's kW, by contrast, is already electrical output, and a heater's or charger's is electrical input.
Is that the current a motor circuit is sized from?+
No. NEC 430.6(A)(1) requires the full-load current tables — 430.248 for single-phase and 430.250 for three-phase motors — rather than the nameplate current for sizing conductors and short-circuit and ground-fault protection, and overload protection is set from the nameplate current. The conversion here is an estimate of what the motor draws, which is useful for a load estimate and not for the motor circuit itself.
What is the difference between kW and kVA?+
kW is real power, the part doing work; kVA is apparent power, volts times amps, which is what the wiring carries. They are related by the power factor: kVA = kW ÷ power factor. A 40 kW load at a power factor of 0.8 is 50 kVA. That is why a kW to amps conversion needs a power factor and a kVA to amps conversion does not, and why transformers and many generators are rated in kVA.
Which voltage do I use on three-phase?+
The line-to-line voltage: 208, 240 or 480. On a 208Y/120 or 480Y/277 system, the second number is the line-to-neutral voltage, and putting it into the three-phase formula overstates the current by about 1.73 times. The tool flags 120 V and 277 V entries on three-phase and shows the corrected figure.
Is this a determination?+
No. It reproduces the standard conversion arithmetic as a preparation aid. It does not size conductors or overcurrent protection, does not replace the NEC Article 430 tables for motor circuits, and does not size a generator for a building. Confirm against the equipment nameplate and installation instructions, and with the authority having jurisdiction.
Related resources
kVA to Amps Calculator
Full-load current from a transformer or generator rating, with no power factor.
Learn more →What Is Power Factor?
Real, reactive and apparent power, and why kW and kVA differ.
Learn more →Solar Backfeed Capacity Calculator
Whether an inverter's output current fits the panel busbar.
Learn more →Solar Design and Permitting
Where equipment ratings become a plan set an inspector can follow.
Learn more →Electrical design that holds up at inspection
Seamless Home runs the design, engineering and permit layer for the partners it works with, which is where equipment ratings are carried through to circuits on a plan set rather than converted on a job site. Coverage is confirmed per service area rather than promised as blanket availability.
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