swap_horiz Looking to convert 42A at 24V back to watts?

How Many Amps Is 1,008 Watts at 24V?

1,008 watts equals 42 amps at 24V on a DC circuit. On AC single-phase at PF 0.85 the same real power would be 49.41 amps.

At 42A, the NEC 210.19(A) continuous-load sizing math (125% of the load, equivalently 80% of the breaker rating) points to a 60A breaker as the smallest standard size that covers this load continuously. A 45A breaker is the smallest standard size the raw current fits under, but it is non-continuous-only at this load.

1,008 watts at 24V
42 Amps
1,008 watts equals 42 amps at 24 volts (DC)
AC Single Phase (PF 0.85)49.41 A
42

Assumes a DC circuit. Typing a commercial L-L voltage (208/400/480V) re-routes the result to three-phase; 277V stays on single-phase because it's the L-N lighting leg of a 480Y/277V wye; 12/24V re-routes to DC.

Formulas

DC: Watts to Amps

I(A) = P(W) ÷ V(V)

1,008 ÷ 24 = 42 A

AC Single Phase (PF = 0.85)

I(A) = P(W) ÷ (PF × V(V))

1,008 ÷ (0.85 × 24) = 1,008 ÷ 20.4 = 49.41 A

Circuit Sizing

Breaker Sizing

NEC 240.6(A) standard ampere ratings for branch-circuit and feeder breakers start at 15, 20, 25, 30, 35, 40, 45, and 50A and continue at 60A and above for feeder and large-appliance circuits. At 42A, the smallest standard breaker the raw current fits under is 45A, but that breaker only covers 45A non-continuously; NEC 210.19(A) requires conductor and OCP sized at 125% of any continuous load (equivalently 80% of breaker rating), so for a continuous load the smallest compliant breaker is 60A. Final selection still depends on the equipment nameplate, whether the load is continuous, conductor ampacity, and local code.

Breaker SizeMax Continuous Load (80%)Status for 42A
30A24AToo small
35A28AToo small
40A32AToo small
45A36ANon-continuous only
50A40ANon-continuous only
60A48AOK for continuous
70A56AOK for continuous
80A64AOK for continuous
90A72AOK for continuous

Energy Cost

Running 1,008W costs approximately $0.17 per hour at the US average rate of $0.17/kWh (rates last reviewed April 2026). That is $1.37 for 8 hours or about $41.13 per month. See detailed cost breakdown.

AC Conversion Detail

The DC baseline for 1,008W at 24V is 42A. On an AC circuit with a power factor of 0.85, the current rises to 49.41A because reactive current flows alongside the real-power current.

Circuit TypeFormulaResult
DC1,008 ÷ 2442 A
AC Single Phase (PF 0.85)1,008 ÷ (24 × 0.85)49.41 A

Power Factor Reference

Power factor is the main reason 1,008W draws more current on AC than DC. At PF 1.0 (pure resistive, like a heater), the load pulls 42A at 24V on the single-phase basis the rest of the page uses. At PF 0.80 (typical induction motor), the same 1,008W pulls 52.5A. That is an extra 10.5A just to overcome the reactive component. Use the typical values below as a starting point, not for precise engineering calculations.

Load TypeTypical PF1,008W at 24V (single-phase)
Resistive (heaters, incandescent)142 A
Fluorescent lamps0.9544.21 A
LED lighting0.946.67 A
Synchronous motors0.946.67 A
Typical mixed loads0.8549.41 A
Induction motors (full load)0.852.5 A
Computers (without PFC)0.6564.62 A
Induction motors (no load)0.35120 A

Other Wattages at 24V

WattsDC AmpsAC 1Φ Amps PF 0.85
250W10.42A12.25A
300W12.5A14.71A
350W14.58A17.16A
400W16.67A19.61A
450W18.75A22.06A
500W20.83A24.51A
600W25A29.41A
700W29.17A34.31A
750W31.25A36.76A
800W33.33A39.22A
900W37.5A44.12A
1,000W41.67A49.02A
1,100W45.83A53.92A
1,200W50A58.82A
1,300W54.17A63.73A
1,400W58.33A68.63A
1,500W62.5A73.53A
1,600W66.67A78.43A
1,700W70.83A83.33A
1,800W75A88.24A

Frequently Asked Questions

1,008W at 24V draws 42 amps on DC. For comparison at the same voltage: 42A on DC, 49.41A on AC single-phase at PF 0.85. Actual current depends on the load's power factor.
AC circuits with reactive loads have a power factor below 1.0, so they draw extra current. At PF 0.85, 1,008W at 24V draws 49.41A instead of 42A (DC). That is about 18% more current for the same real power.
24V is not a standard household receptacle voltage in the US. It is used on commercial or industrial panels and typically feeds hardwired equipment or specialty twistlock receptacles, not plug-in appliances. Any 1,008W load at this voltage is a dedicated-circuit, nameplate-driven install, not a plug-in decision.
Yes. Higher voltage means lower current for the same real power. 1,008W at 24V draws 42A on DC. As a resistive-baseline comparison at the same wattage, a DC or PF 1.0 load would draw 84A at 12V and 21A at 48V. Doubling the voltage halves the current and also halves the I²R losses in the conductors.
At 42A on 24V, branch-circuit sizing depends on whether the load is continuous (NEC 210.19(A) applies the 125% continuous-load rule), the equipment nameplate FLA, and the conductor and termination ratings. 24V is a commercial or industrial panel voltage, not a typical household receptacle voltage.
This calculator provides estimates for reference purposes only. Always consult a licensed electrician and verify compliance with the National Electrical Code (NEC) and local electrical codes before performing any electrical work.