How to convert watts to amperes

Content

Steps
Method 1 of 3: Converting Watts to Amps at a Fixed Voltage
Method 2 of 3: Converting Watts to Amperes at Constant Voltage
Method 3 of 3: Converting Watts to Amperes for Single Phase AC Voltage
Tips
Warnings
What do you need

Despite the impossibility of directly “converting” watts to amperes, you can calculate the corresponding number of amperes using the ratio between amperes, watts and electrical voltage.Despite the fact that this ratio is different for different types of electrical circuits (direct and alternating current), for a certain type of circuit it remains unchanged. For fixed voltage circuits, power and amperage are often used interchangeably, in which case it is very useful to know how to convert watts to amperes.

Steps

Method 1 of 3: Converting Watts to Amps at a Fixed Voltage

1 Make a table for converting watts to amperes. Many circuits, such as a home network or a car, use a fixed voltage. In this case, there is an unambiguous relationship between power and current. Thus, you can compile a table using the relationships between power (watts), current (amperes) and voltage (volts) in any electrical circuit. A similar table can be found on the Internet. In this case, you should choose a table that is suitable for the voltage you are using.
- For example, a home network typically uses 220 volts AC, while cars use 12 volts DC.
- You can make it even easier for yourself by using an online calculator to convert watts to amps.
2 Find the amount of power (in watts) you want to convert to amperage. After compiling a table or finding it on the Internet, find the power you are interested in. Typically, such tables consist of several rows and columns. Your table should have a column entitled “Power” or “Watts”. Find this column and scroll through it to find the power value that matches your electrical circuit.
3 Find the corresponding current (in amperes). After you find the power you are interested in (in watts), go along the same line to the “Current” or “Amperes” column. There can be more than two columns in a table, so pay attention to their headers so as not to be mistaken. Once you find the column with the current values in amperes, double-check that the corresponding current value is in the same row as the wattage you are interested in.

Method 2 of 3: Converting Watts to Amperes at Constant Voltage

1 Determine the power of the chain. Check out the characteristics of the circuit you are interested in. Power is measured in watts. The amount of power characterizes the amount of energy consumed or generated in the circuit per unit of time. So 1 watt = 1 joule / 1 second. The amount of power you need to know in order to find the current, measured in amperes (abbreviated "A").
2 Determine the voltage. Voltage is the difference in electrical potential in a circuit, and along with power, it is also indicated in the characteristics of the circuit. The stress arises from the excess at one end of the circuit and a shortage of electrons at the other. As a result, an electric field (potential difference) arises between the ends of the circuit. This potential difference, that is, the voltage, leads to the fact that an electric current flows through the circuit, striving to remove the voltage (equalize the charges at different ends of the circuit). To find the current (number of amperes), you must determine the voltage value.
3 Write down the equation. For DC, the equation looks very simple. Watts are equal to amperes divided by volts. Thus, by dividing watts by volts, you will find out the current strength (number of amperes) in the network.
- Amperes = watts / volts
4 Find the amperage. By writing down the equation, you can find the number of amperes. To do this, perform division. Check the units: you should end up with pendants divided by a second. 1 amp = 1 coulomb / second.
- In the international system of units (SI), coulombs are the unit of measure for electric charge. In this case, one ampere corresponds to a charge of one coulomb that has flowed through the cross-section of the conductor in one second.

Method 3 of 3: Converting Watts to Amperes for Single Phase AC Voltage

1 Determine the power factor. The power factor of a circuit is equal to the ratio of the active power to the apparent power supplied to the circuit.The apparent power is always greater than or equal to the active power, so the power factor ranges from 0 to 1. Find the power factor shown in the circuit description or diagram.
2 Use the equation for single phase circuits. The equation for single phase AC circuits is similar to the equation used above for DC and relates volts, amperes and watts. The difference is that for AC, the power factor is included in the equation.
- Amperes = watts / (KM X volts) where power factor (KM) is a dimensionless quantity.
3 Find the current. By plugging in watts, volts, and power factor, you can find the number of amps. As a result, you will get the number of pendants per second. If you get other units of measurement, check the equation again - you may have written it incorrectly.
- The equation for three-phase circuits includes more quantities than for single-phase circuits. To calculate the number of amperes in a three-phase circuit, you must determine whether you are connecting to two phases or a phase and zero.

Tips

Use a calculator.
Remember that you are calculating amperes from given watts and volts. You cannot simply “convert” watts to amperes, since they measure different physical quantities.