Amps to kW 240V
Convert current to kW on a 240 V supply and see which breaker in a 240 V panel suits your load.
Inputs
Breaker panel at this voltage
How amps to kW 240V calculator works
The amps to kW 240V calculator converts current into kilowatts (kW) on a 240 V supply with 2 inputs: current and power factor. The calculator suggests the breaker at 125% of the current and shows the kW each breaker size carries at 240 V.
P = I × 240 × PF / 100030 A at 240 V gives 7.2 kW and needs a 40 A breaker. The breaker panel shows 12 breaker sizes from 15 A to 200 A.
Amps to kW 240V formula
The amps to kW 240V formula is P(kW) = I(A) × 240 × PF / 1,000. There are 3 formulas at 240 V: real power, continuous load and breaker size.
Real power
P = I × 240 × PF / 100030 A × 240 V / 1,000 = 7.2 kW
Continuous load (80%)
Pcont = 0.8 × Breaker × 240 / 10000.8 × 50 A × 240 V / 1,000 = 9.6 kW
Breaker size
Breaker ≥ 1.25 × I1.25 × 30 A = 37.5 A → 40 A breaker
North American homes receive 120/240 V split phase: 240 V between the 2 hot legs for dryers, ranges and electric vehicle (EV) chargers. The NEC limits continuous loads to 80% of the breaker rating.
Amps to kW 240V conversion chart
The amps to kW 240V conversion chart lists 12 breaker and load sizes from 15 A to 200 A at 240 V, with full kW, continuous kW at 80% and kW at power factor 0.9.
| Amps | 240 VPF 1 | 80% loadkW | 240 VPF 0.9 |
|---|---|---|---|
| 15 A | 3.6 | 2.88 | 3.24 |
| 20 A | 4.8 | 3.84 | 4.32 |
| 30 A | 7.2 | 5.76 | 6.48 |
| 40 A | 9.6 | 7.68 | 8.64 |
| 50 A | 12 | 9.6 | 10.8 |
| 60 A | 14.4 | 11.52 | 12.96 |
| 70 A | 16.8 | 13.44 | 15.12 |
| 80 A | 19.2 | 15.36 | 17.28 |
| 100 A | 24 | 19.2 | 21.6 |
| 125 A | 30 | 24 | 27 |
| 150 A | 36 | 28.8 | 32.4 |
| 200 A | 48 | 38.4 | 43.2 |
A 200 A, 240 V service carries 48 kW in total and 38.4 kW of continuous load.
Amps to kW 240V Excel formula
The amps to kW 240V Excel formula is =A2*240*B2/1000 with amps in A2 and power factor in B2.
| A | B | C | D | E | |
|---|---|---|---|---|---|
| 1 | Amps | Volts | PF | kW | Formula in D |
| 2 | 30 | 240 | 1 | 7.2 | =ROUND(A2*B2*C2/1000,2) |
| 3 | 50 | 240 | 1 | 12 | =ROUND(A3*B3*C3/1000,2) |
| 4 | 40 | 240 | 0.9 | 8.64 | =ROUND(A4*B4*C4/1000,2) |
Add =D2*0.8 in column E to get the continuous kW a breaker of that size carries.
Amps to kW 240V equation
The amps to kW 240V equation is P = I × 240 × PF / 1,000, where 240 is the supply voltage in volts.
- P
- Real power in kW
- I
- Current in amperes (A)
- 240
- Supply voltage (V)
- PF
- Power factor
Power rises 0.24 kW for every amp at PF 1, double the 0.12 kW per amp at 120 V.
Amps to kW 240V FAQ
How many kW is 30 amps at 240V?
30 amps at 240V is 7.2 kW at a power factor of 1.
How many kW is 50 amps at 240V?
50 amps at 240V is 12 kW at a power factor of 1, or 9.6 kW of continuous load on a 50 A breaker.
How many kW is a 200 amp 240V service?
A 200 amp 240V service is 48 kW, with 38.4 kW available for continuous loads at 80%.
How many amps is 10 kW at 240V?
10 kW at 240V is 41.67 A at a power factor of 1.