Amps to watts
Watts equal amps times volts, times the power factor on AC. Eight amps at 230 V with a power factor of 1 is 1,840 W. At a 0.8 power factor the same current is only 1,472 W of real power but still 1,840 VA of apparent power.
How to convert amps to watts
A clamp meter tells you current, not power, and the leap between them is where the power factor lives. For a kettle or heater the two are the same and the multiplication is exact. For a motor, a fluorescent ballast or an old switch-mode supply, current lags or distorts and real power can be well below the apparent figure. If you are estimating running cost from a clamp reading, an assumed power factor of 1 will overstate the bill for motor loads: a plug-in energy meter measures true power directly and settles the question.
Questions
1,840 W at 230 V or 960 W at 120 V, assuming a power factor of 1.
Labels quote maximum draw; most appliances cycle or modulate. A fridge nameplate is its compressor running, not its average.
One for heating and lighting. For motors, 0.8 to 0.9. If accuracy matters, measure with a true-power meter.
Only when power factor is 1. Otherwise VA is the larger figure, and it is what cables and generators must be sized for.
Yes. Switch the supply to three phase and the tool applies the √3 factor to the line values.