# QuestionHow can I determine how much power I CAN use?

#### MaiYass

Apologies if I'm just not understanding this correctly, as I'm quite new to this stuff. Based off of this calculator, I can narrow my use to about 190-320 watts with my current build, and after changing the settings to my planned build, I'll be using around 285-415 watts. What I'm wondering is, how do I know if I'll be able to make this upgrade? Is there a way to know how many watts I CAN use?

#### R_1

##### Splendid
Herald
depends on the PSU. the power supply will dictate how full the tank is so to speak.
not all are telling the truth, you need to look at the label and look at the 12V rail.a 500W unit should provide 450W or more just on the 12V rail. inferior units put all power on the minor rails 3.3 or 5V, but only have 300W on the 12V, where it counts.

a good 600W PSU unit can provide 600W.
look at the label for the +12V rail and multiply that by the listed amperage for the wattage you can use.
12V x 50A = 600W

see this unit under the 5V rail. all the power is there, this 450W unit can only provide 240W

Last edited: