One of the most common types of electricity conversions that must be performed is the transformation from kW (kilowatts) to Amps.
Electrical power is measured in watts, and one kilowatt is equivalent to one thousand watts (wattage).
The ampere, also known as “A,” is the unit of measurement for electrical current. It is abbreviated as “A.” (amperage).
DC KW to Amps Calculation:
The following is the formula for converting kilowatts to amps for direct current:
The power, which is measured in kilowatts (kW), is multiplied by 1000, and then divided by the voltage, which is measured in volts (V): the current, which is measured in amps (A), is proportional to the power.
I = 1000 × P / V
AC KW (Single Phase) to Amps Calculation:
Conversion from kilowatts to amperes (kw to ampere) for alternating current with a single phase:
The phase current I, which is measured in amps (A), is proportional to 1000 times the power P, which is measured in kilowatts (kW). This value is then divided by the power factor PF, which is then multiplied by the RMS voltage V, which is measured in volts (V):
I = 1000 × P / (PF × V)
AC KW (Three Phase) to Amps Calculation:
The following is the conversion from kilowatts to amps for three-phase alternating current:
When doing the calculation, using the voltage from one line to the next:
The phase current I, which is measured in amps (A), is proportional to one thousand times the power P, which is measured in kilowatts (kW), and this value is then divided by the square root of three times the power factor PF, and this value is then multiplied by the line-to-line RMS voltage VL-L, which is measured in volts (V):
I = 1000 × P / (√3 × PF × VL-L)
Using the voltage from the line to the neutral, perform the following calculation:
The phase current I, which is measured in amps (A), is proportional to one thousand times the power P, which is measured in kilowatts (kW), and this value is then divided by three times the power factor PF, and this value is then multiplied by the line-to-neutral RMS voltage, which is measured in volts (V):
I = 1000 × P / (3 × PF × VL-N)
Why convert KW to Amps?
- Kilowatts represent the power utilized by an electrical device, whereas amps measure the current passing through the circuit. Knowing how to convert between them has various advantages.
- Safe Wiring: Calculating the correct wire size for your intended kW is essential to avoiding overheating & potential fire concerns.
- Circuit Breaker Selection: To avoid tripping or overloading, choose the appropriate circuit breaker based on the predicted amp consumption.
- Cost Estimation: Measuring the current drawn by the equipment you use allows you to estimate your electricity cost & plan your energy usage.
- Project Work: A KW to Amps Calculator is a valuable tool for project planning, whether you’re building a DIY solar panel system (or) fixing residential circuits.
Common Power Factor Values
Device/Load | Power Factor |
Incandescent lamps | 1.0 |
Resistive loads | 1.0 |
Synchronous motors | 0.8-0.95 |
Induction motors (small) | 0.7-0.8 |
Induction motors (large) | 0.85-0.95 |
Transformers | 0.8-0.95 |
Fluorescent lighting (magnetic ballast) | 0.7-0.9 |
Fluorescent lighting (electronic ballast) | 0.9-0.99 |
Computers and electronics | 0.6-0.8 |
Note
The power factor figures shown here are approximations and may vary depending on the specific appliance, load, and other factors involved. When designing and implementing electrical systems, it important to consider the power factor to ensure efficiency and reduce energy costs.
Conversion Table: Amps and Kilowatts at 120V AC
Motor Current Ratings – Three-Phase AC Supply
Motor current ratings with an efficiency of 0.8 & a power-factor of 1 are based on kilowatt (KW) output at 120V, 208V, 240V, 277V, & 480V three-phase AC supply.
Power | Current (120V) | Current (208V) | Current (240V) | Current (277V) | Current (480V) | |
1KW | 6.014A | 3.47A | 3.007A | 2.605A | 1.504A | |
2KW | 12.028A | 6.939A | 6.014A | 5.211A | 3.007A | |
3KW | 18.042A | 10.409A | 9.021A | 7.816A | 4.511A | |
4KW | 24.056A | 13.879A | 12.028A | 10.421A | 6.014A | |
5KW | 30.07A | 17.348A | 15.035A | 13.027A | 7.518A | |
6KW | 36.084A | 20.818A | 18.042A | 15.632A | 9.021A | |
7KW | 42.098A | 24.288A | 21.049A | 18.238A | 10.525A | |
8KW | 48.113A | 27.757A | 24.056A | 20.843A | 12.028A | |
9KW | 54.127A | 31.227A | 27.063A | 23.448A | 13.532A | |
10KW | 60.141A | 34.697A | 30.07A | 26.054A | 15.035A | |
15KW | 90.211A | 52.045A | 45.105A | 39.081A | 22.553A | |
20KW | 120.28A | 69.393A | 60.141A | 52.107A | 30.07A | |
25KW | 150.35A | 86.741A | 75.176A | 65.134A | 37.588A | |
30KW | 180.42A | 104.09A | 90.211A | 78.161A | 45.105A | |
35KW | 210.49A | 121.44A | 105.25A | 91.188A | 52.623A | |
40KW | 240.56A | 138.79A | 120.28A | 104.21A | 60.141A | |
45KW | 270.63A | 156.13A | 135.32A | 117.24A | 67.658A | |
50KW | 300.7A | 173.48A | 150.35A | 130.27A | 75.176A | |
55KW | 330.77A | 190.83A | 165.39A | 143.3A | 82.693A | |
60KW | 360.84A | 208.18A | 180.42A | 156.32A | 90.211A | |
65KW | 390.91A | 225.53A | 195.46A | 169.35A | 97.729A | |
70KW | 420.98A | 242.88A | 210.49A | 182.38A | 105.25A | |
75KW | 451.05A | 260.22A | 225.53A | 195.4A | 112.76A | |
80KW | 481.13A | 277.57A | 240.56A | 208.43A | 120.28A | |
85KW | 511.2A | 294.92A | 255.6A | 221.46A | 127.8A | |
90KW | 541.27A | 312.27A | 270.63A | 234.48A | 135.32A | |
95KW | 571.34A | 329.62A | 285.67A | 247.51A | 142.83A | |
100KW | 601.41A | 346.97A | 300.7A | 260.54A | 150.35A | |
125KW | 751.76A | 433.71A | 375.88A | 325.67A | 187.94A | |
150KW | 902.11A | 520.45A | 451.05A | 390.81A | 225.53A | |
175KW | 1,052.5A | 607.19A | 526.23A | 455.94A | 263.12A | |
200KW | 1,202.8A | 693.93A | 601.41A | 521.07A | 300.7A | |
225KW | 1,353.2A | 780.67A | 676.58A | 586.21A | 338.29A | |
250KW | 1,503.5A | 867.41A | 751.76A | 651.34A | 375.88A | |
275KW | 1,653.9A | 954.15A | 826.93A | 716.48A | 413.47A | |
300KW | 1,804.2A | 1,040.9A | 902.11A | 781.61A | 451.05A | |
325KW | 1,954.6A | 1,127.6A | 977.29A | 846.75A | 488.64A | |
350KW | 2,104.9A | 1,214.4A | 1,052.5A | 911.88A | 526.23A | |
375KW | 2,255.3A | 1,301.1A | 1,127.6A | 977.01A | 563.82A | |
400KW | 2,405.6A | 1,387.9A | 1,202.8A | 1,042.1A | 601.41A | |
425KW | 2,556A | 1,474.6A | 1,278A | 1,107.3A | 638.99A | |
450KW | 2,706.3A | 1,561.3A | 1,353.2A | 1,172.4A | 676.58A | |
475KW | 2,856.7A | 1,648.1A | 1,428.3A | 1,237.6A | 714.17A | |
500KW | 3,007A | 1,734.8A | 1,503.5A | 1,302.7A | 751.76A | |
525KW | 3,157.4A | 1,821.6A | 1,578.7A | 1,367.8A | 789.35A | |
550KW | 3,307.7A | 1,908.3A | 1,653.9A | 1,433A | 826.93A | |
575KW | 3,458.1A | 1,995.1A | 1,729A | 1,498.1A | 864.52A | |
600KW | 3,608.4A | 2,081.8A | 1,804.2A | 1,563.2A | 902.11A | |
625KW | 3,758.8A | 2,168.5A | 1,879.4A | 1,628.4A | 939.7A | |
650KW | 3,909.1A | 2,255.3A | 1,954.6A | 1,693.5A | 977.29A | |
675KW | 4,059.5A | 2,342A | 2,029.7A | 1,758.6A | 1,014.9A | |
700KW | 4,209.8A | 2,428.8A | 2,104.9A | 1,823.8A | 1,052.5A | |
725KW | 4,360.2A | 2,515.5A | 2,180.1A | 1,888.9A | 1,090A | |
750KW | 4,510.5A | 2,602.2A | 2,255.3A | 1,954A | 1,127.6A | |
775KW | 4,660.9A | 2,689A | 2,330.5A | 2,019.2A | 1,165.2A | |
800KW | 4,811.3A | 2,775.7A | 2,405.6A | 2,084.3A | 1,202.8A | |
825KW | 4,961.6A | 2,862.5A | 2,480.8A | 2,149.4A | 1,240.4A | |
850KW | 5,112A | 2,949.2A | 2,556A | 2,214.6A | 1,278A | |
875KW | 5,262.3A | 3,035.9A | 2,631.2A | 2,279.7A | 1,315.6A | |
900KW | 5,412.7A | 3,122.7A | 2,706.3A | 2,344.8A | 1,353.2A | |
925KW | 5,563A | 3,209.4A | 2,781.5A | 2,410A | 1,390.8A | |
950KW | 5,713.4A | 3,296.2A | 2,856.7A | 2,475.1A | 1,428.3A | |
975KW | 5,863.7A | 3,382.9A | 2,931.9A | 2,540.2A | 1,465.9A | |
1000KW | 6,014.1A | 3,469.7A | 3,007A | 2,605.4A | 1,503.5A | |
Motor Current Ratings – Single-Phase AC Supply
Motor current ratings with an efficiency of 0.8 & a power-factor of 1 are based on kilowatt (KW) output at 120V & 240V single-phase AC supply.
Power | Current (120V) | Current (240V) |
1KW | 10.417A | 5.208A |
2KW | 20.833A | 10.417A |
3KW | 31.25A | 15.625A |
4KW | 41.667A | 20.833A |
5KW | 52.083A | 26.042A |
6KW | 62.5A | 31.25A |
7KW | 72.917A | 36.458A |
8KW | 83.333A | 41.667A |
9KW | 93.75A | 46.875A |
10KW | 104.17A | 52.083A |
15KW | 156.25A | 78.125A |
20KW | 208.33A | 104.17A |
25KW | 260.42A | 130.21A |
30KW | 312.5A | 156.25A |
35KW | 364.58A | 182.29A |
40KW | 416.67A | 208.33A |
45KW | 468.75A | 234.38A |
50KW | 520.83A | 260.42A |
55KW | 572.92A | 286.46A |
60KW | 625A | 312.5A |
65KW | 677.08A | 338.54A |
70KW | 729.17A | 364.58A |
75KW | 781.25A | 390.63A |
80KW | 833.33A | 416.67A |
85KW | 885.42A | 442.71A |
90KW | 937.5A | 468.75A |
95KW | 989.58A | 494.79A |
100KW | 1,041.7A | 520.83A |
125KW | 1,302.1A | 651.04A |
150KW | 1,562.5A | 781.25A |
175KW | 1,822.9A | 911.46A |
200KW | 2,083.3A | 1,041.7A |
225KW | 2,343.8A | 1,171.9A |
250KW | 2,604.2A | 1,302.1A |
275KW | 2,864.6A | 1,432.3A |
300KW | 3,125A | 1,562.5A |
325KW | 3,385.4A | 1,692.7A |
350KW | 3,645.8A | 1,822.9A |
375KW | 3,906.3A | 1,953.1A |
400KW | 4,166.7A | 2,083.3A |
425KW | 4,427.1A | 2,213.5A |
450KW | 4,687.5A | 2,343.8A |
475KW | 4,947.9A | 2,474A |
500KW | 5,208.3A | 2,604.2A |
525KW | 5,468.8A | 2,734.4A |
550KW | 5,729.2A | 2,864.6A |
575KW | 5,989.6A | 2,994.8A |
600KW | 6,250A | 3,125A |
625KW | 6,510.4A | 3,255.2A |
650KW | 6,770.8A | 3,385.4A |
675KW | 7,031.3A | 3,515.6A |
700KW | 7,291.7A | 3,645.8A |
725KW | 7,552.1A | 3,776A |
750KW | 7,812.5A | 3,906.3A |
775KW | 8,072.9A | 4,036.5A |
800KW | 8,333.3A | 4,166.7A |
825KW | 8,593.8A | 4,296.9A |
850KW | 8,854.2A | 4,427.1A |
875KW | 9,114.6A | 4,557.3A |
900KW | 9,375A | 4,687.5A |
925KW | 9,635.4A | 4,817.7A |
950KW | 9,895.8A | 4,947.9A |
975KW | 10,156A | 5,078.1A |
1000KW | 10,417A | 5,208.3A |
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