Volts to Amps Calculator (V to A):
For calculating current from voltage, we can use two methods, one is ohms’ law and another one is power calculations.
Ohms law Resistance method
As you know voltage is the multiplication of current and resistance, hence current can be calculated by dividing the voltage by resistance. Let we find the formula
V(V) = I(A) x R(Ω)
From that, the current in Amps
I(A) = V(V) / R(Ω)
Current = Voltage / Resistance.
Amp = Volts / Resistance.
Volts to Amps conversion – Power Calculation method:
The power is the multiplication of current and voltage. Therefore, the current I(A) can be calculated from the Power P(W) divided by the voltage V(V) in Volts.
P(W) = I(A) * V(V)
Hence, the current I(A)
I(A) = P(W) / V(V)
Current = Power / Voltage
Amps = Watt / Volts
Example:
Calculated the rated current of the 230 Volts, 2645 W, 20 Ohm water heater.
Apply our first method,
I(A) = 230 / 30
Current = 11.5 Amps
Using the Second method,
I(A) = 2645 / 230
Current = 11.5 Amps
Same 11.5 Amps received from our calculations. Hence you can calculate Amps in both ways but you get the same result.
Volts to Amp conversion chart for the standard Motors:
Blow tables are the pre-calculated Volts to Amp conversion value for the different rating of the DC motor at 400 Volts.
| S. No | kW | Watts | DC Volts | Amps |
| 1 | 0.75 | 750 | 400 | 1.88 |
| 2 | 1.1 | 1100 | 400 | 2.75 |
| 3 | 1.5 | 1500 | 400 | 3.75 |
| 4 | 2.2 | 2200 | 400 | 5.50 |
| 5 | 3.7 | 3700 | 400 | 9.25 |
| 6 | 5.5 | 5500 | 400 | 13.75 |
| 7 | 7.5 | 7500 | 400 | 18.75 |
| 8 | 11 | 11000 | 400 | 27.50 |
| 9 | 15 | 15000 | 400 | 37.50 |
| 10 | 22 | 22000 | 400 | 55.00 |
| 11 | 37 | 37000 | 400 | 92.50 |
| 12 | 50 | 50000 | 400 | 125.00 |
| 13 | 75 | 75000 | 400 | 187.50 |
| 14 | 90 | 90000 | 400 | 225.00 |
| 15 | 110 | 110000 | 400 | 275.00 |
| 16 | 132 | 132000 | 400 | 330.00 |
| 17 | 150 | 150000 | 400 | 375.00 |
| 18 | 175 | 175000 | 400 | 437.50 |
| 19 | 220 | 220000 | 400 | 550.00 |
| 20 | 250 | 250000 | 400 | 625.00 |
| 21 | 280 | 280000 | 400 | 700.00 |
| 22 | 310 | 310000 | 400 | 775.00 |
| 23 | 350 | 350000 | 400 | 875.00 |
| 24 | 375 | 375000 | 400 | 937.50 |
| 25 | 420 | 420000 | 400 | 1050.00 |