how to convert amps/voltage to watt's?

Question

I am using a invertor in my truck and want to buy a vacum but there all listed with amps and volts i need to know if my 800 watt invertor can handle it

Answer 1

Ok here is the formula to convert
If it's D.C. system then
P=VI
If it's a A.C. system then
P=VI cos(fi) where cos(fi) is the power factor.An Inverter converts D.C. to A.C.So the system must be A.C.If you tell us the ratings written we can help you

Answer 2

The actual formula is P=V x I or power in watts = voltage x amps.

So for your 800 watt inverter can give you about 6.5 amps.