Appliances are commonly rated in terms of watts, so it’s more convenient to estimate the electrical load of a circuit at home in terms of power. For example, we can estimate the maximum sum of electrical power that can be plugged into a 10 amp circuit.
How many watts is 10 amps? The answer can be 120 watts at 12 volts, 1200 watts at 120 volts, and 2400 watts at 240 volts.
Volts Amps Watts Formula:
- Electric power can be defined as:
Power (watts) = Current (amps) × Voltage (volts)
- This means we can calculate watts from amps depending on the voltage of the circuit. For instance, if we want to calculate the watts of 10 amps at 110 volts, then:
Power (watts) = Current (amps) × Voltage (volts) = 10 amps × 110 volts = 1100 watts
- We can try another example. If we want to calculate watts of 10 amps at 12 volts, then:
Power (watts) = Current (amps) × Voltage (volts) = 10 amps × 12 volts = 120 watts
- Similarly, we can use the formula to convert watts to amps at a given voltage. We can rearrange the formula to get:
Current (amps) = Power (watts) / Voltage (volts)
- For example, if we want to determine the current draw of a 2000 watt appliance at 220 volts, then the formula to calculate amps from watts would be:
Current (amps) = Power (watts) / Voltage (volts) = 2000 watts / 220 volts = 9.1 amps
- Lastly, we can also convert amps to volts for an appliance with a given power rating using:
Voltage (volts) = Power (watts) / Current (amps)
- If we want to know the voltage needed to power a 1200 watt appliance at 5 amps, then:
Voltage (volts) = Power (watts) / Current (amps) = 1200 watts / 5 amps = 240 volts
1. When calculating, you should take into account the power factor for more accuracy. In this case, the formula would be watt = volt x amp x power factor. TVs, stereos, and fluorescent lights, for example, often have a power factor of 0.4 to 0.8.
2. For line-to-line voltage setups, add √3 to the wattage equation, while for line-to-neutral circuits, add 3.
Electric Power at Different Voltages
You can convert amps to watts using the equation above, but we provided a table for ease of reference. It can also be used to estimate watt to amps conversion.
| Current (amps) | Power (watts) at different voltages | |||||
| 12 volts | 24 volts | 110 volts | 120 volts | 220 volts | 240 volts | |
| 0.5 | 6 | 12 | 55 | 60 | 110 | 120 |
| 1 | 12 | 24 | 110 | 120 | 220 | 240 |
| 2 | 24 | 48 | 220 | 240 | 440 | 480 |
| 3 | 36 | 72 | 330 | 360 | 660 | 720 |
| 4 | 48 | 96 | 440 | 480 | 880 | 960 |
| 5 | 60 | 120 | 550 | 600 | 1100 | 1200 |
| 6 | 72 | 144 | 660 | 720 | 1320 | 1440 |
| 7 | 84 | 168 | 770 | 840 | 1540 | 1680 |
| 8 | 96 | 192 | 880 | 960 | 1760 | 1920 |
| 9 | 108 | 216 | 990 | 1080 | 1980 | 2160 |
| 10 | 120 | 240 | 1100 | 1200 | 2200 | 2400 |
| 15 | 180 | 360 | 1650 | 1800 | 3300 | 3600 |
| 20 | 240 | 480 | 2200 | 2400 | 4400 | 4800 |
| 25 | 300 | 600 | 2750 | 3000 | 5500 | 6000 |
| 30 | 360 | 720 | 3300 | 3600 | 6600 | 7200 |
| 35 | 420 | 840 | 3850 | 4200 | 7700 | 8400 |
| 40 | 480 | 960 | 4400 | 4800 | 8800 | 9600 |
| 45 | 540 | 1080 | 4950 | 5400 | 9900 | 10800 |
| 50 | 600 | 1200 | 5500 | 6000 | 11000 | 12000 |
Conclusion
Calculating the power of a line in watts can be done in a few minutes. Knowing how many watts is 10 amps can help us prepare for electrical installations in residences.
The formula can be used to convert between amps, watts and volts. As long as the formula can be manipulated well, the conversion of amps to watts will not be a problem, regardless of how high the voltage will be.
I am Edwin Jones, in charge of designing content for Galvinpower. I aspire to use my experiences in marketing to create reliable and necessary information to help our readers. It has been fun to work with Andrew and apply his incredible knowledge to our content.