resistors - What potentiometer should I use for my led strip?

I have a led strip, this led strip is consuming about 2.5A @ 12V.
Before, I was using an Arduino to modulate the intensity of the light with PWM but I realized that a simple circuit would be even better for what I want.

I am wondering what potentiometer should I use to get the same result than when I was using the PWM, because when I was using the PWM of the Arduino, I often putted it to "1 out of 255" to get a really soft light, so what is the equivalent resistance to "1 out of 255" ? Am I right to think that my potentiometer will have to go from 0 ohms to this specific resistance ?

^{simulate this circuit – Schematic created using CircuitLab}