Amp to kW per hour
Enter the current, voltage and running time to see the power in kW and how many kWh the load uses every hour.
Inputs
Energy used hour by hour
How amp to kW per hour calculator works
The amp to kW per hour calculator converts current into the kilowatt-hours (kWh) a load uses each hour with 5 inputs: current, voltage, power factor, current type and running time. The calculator finds power in kilowatts (kW) first and multiplies kW by the running time in hours (h).
E = I × V × PF × t / 100010 A at 230 V and PF 0.9 gives 2.07 kW, so the load uses 2.07 kWh every hour and 16.56 kWh (59.6 megajoules, MJ) over 8 hours. The bar chart shows the energy adding up hour by hour.
Amp to kW per hour formula
The amp to kW per hour formula is kWh per hour = A × V × PF / 1,000 for single-phase alternating current (AC). There are 3 amp to kW per hour formulas: single-phase energy per hour, three-phase energy per hour and total energy over a running time.
Single phase, per hour
kWh/h = I × V × PF / 100010 A × 230 V × 0.9 / 1,000 = 2.07 kWh
Three phase, per hour
kWh/h = √3 × I × V × PF / 10001.732 × 16 A × 400 V × 0.85 / 1,000 = 9.42 kWh
Total energy
E(kWh) = P(kW) × t(h)2.07 kW × 8 h = 16.56 kWh
A load of 1 kW running for 1 hour uses 1 kWh, which equals 3.6 MJ or 3,412 British thermal units (BTU). The kW value and the kWh-per-hour value are the same number.
Amp to kW per hour conversion chart
The amp to kW per hour conversion chart lists the kWh used each hour by 11 currents from 1 A to 50 A at 120 V, 230 V and 240 V, plus the total kWh over 8 hours and 24 hours at 230 V. The chart uses a power factor of 1.
| Amps | 120 VkWh / h | 230 VkWh / h | 240 VkWh / h | 230 V8 h kWh | 230 V24 h kWh |
|---|---|---|---|---|---|
| 1 A | 0.12 | 0.23 | 0.24 | 1.84 | 5.52 |
| 2 A | 0.24 | 0.46 | 0.48 | 3.68 | 11.04 |
| 5 A | 0.6 | 1.15 | 1.2 | 9.2 | 27.6 |
| 10 A | 1.2 | 2.3 | 2.4 | 18.4 | 55.2 |
| 13 A | 1.56 | 2.99 | 3.12 | 23.92 | 71.76 |
| 16 A | 1.92 | 3.68 | 3.84 | 29.44 | 88.32 |
| 20 A | 2.4 | 4.6 | 4.8 | 36.8 | 110.4 |
| 25 A | 3 | 5.75 | 6 | 46 | 138 |
| 32 A | 3.84 | 7.36 | 7.68 | 58.88 | 176.64 |
| 40 A | 4.8 | 9.2 | 9.6 | 73.6 | 220.8 |
| 50 A | 6 | 11.5 | 12 | 92 | 276 |
Multiply a chart value by the real power factor for motors, for example × 0.85. 13 A at 230 V uses 2.99 kWh per hour and 71.8 kWh per day.
Amp to kW per hour Excel formula
The amp to kW per hour Excel formula is =A2*B2*C2*D2/1000 with amps in A2, volts in B2, power factor in C2 and hours in D2. Add SQRT(3)* at the start for three-phase rows.
| A | B | C | D | E | F | |
|---|---|---|---|---|---|---|
| 1 | Amps | Volts | PF | Hours | kWh | Formula in E |
| 2 | 10 | 230 | 0.9 | 8 | 16.56 | =ROUND(A2*B2*C2*D2/1000,2) |
| 3 | 16 | 240 | 1 | 5 | 19.2 | =ROUND(A3*B3*C3*D3/1000,2) |
| 4 | 32 | 400 | 0.85 | 10 | 188.45 | =ROUND(SQRT(3)*A4*B4*C4*D4/1000,2) |
Row 4 is a three-phase load. Multiply column E by the tariff per kWh in a sixth column to get the running cost.
Amp to kW per hour equation
The amp to kW per hour equation is E = I × V × PF × t / 1,000, where E is energy in kWh and t is the running time in hours.
- E
- Energy in kilowatt-hours (kWh)
- I
- Current in amperes (A)
- V
- Voltage in volts (V)
- PF
- Power factor, 1 for DC and heaters
- t
- Running time in hours (h)
Energy grows in a straight line with time: doubling the hours doubles the kWh. A 2 kW heater uses 2 kWh in 1 hour, 4 kWh in 2 hours and 48 kWh in 24 hours.
Amp to kW per hour FAQ
How many kWh does 1 amp use per hour?
1 amp uses 0.23 kWh per hour at 230 V and 0.12 kWh per hour at 120 V, at a power factor of 1. Over 24 hours, 1 A at 230 V uses 5.52 kWh.
How many kWh is 10 amps per hour?
10 amps is 2.3 kWh per hour at 230 V, 2.4 kWh per hour at 240 V and 1.2 kWh per hour at 120 V, at a power factor of 1.
Is kW per hour the same as kWh?
No, kW per hour and kWh are different quantities. kW measures power and kWh measures energy. The phrase "amp to kW per hour" asks for the kWh a load uses in 1 hour, which equals the kW value: a 2 kW load uses 2 kWh in 1 hour.
How much does 13 amps cost per hour?
13 amps at 230 V uses 2.99 kWh per hour and costs 0.45 per hour at a tariff of 0.15 per kWh (dollars, pounds or euros). At 0.30 per kWh the same load costs 0.9 per hour.