Hi homies
I have a - perhaps simply - question, so bare with me.
I have been looking up brushless motors and ducted fans for an upcoming project.
The motors list the amount of thust they can provide, but what is the vertical lifting power of the motor?

Like if the ducted fan + motor weighs 500g and has a thrust of 5kg, will it - in theory - be able to life 4.5kg?

It depends on the weight of the plane and also the amount of lift the wings will generate. As a rule of thumb, a power plant the provides say 5 kg of thrust will lift a plane of 4.5kg with ease.

When calculating the lifting power (thrust?) of the brushless motor, I am only thinking vertical take off, there is no level flight in the scenario.

Then yes. It should be able to. But also you need to think of HOW it would achieve vertical flight, or are you just asking about the mathematics? if it is just mathematics, then I think that you would need to subtract the weight of the engine from the amount of thrust given, like you said.