Filled circle with exact pixel count

[cyborg]

hi!
i've got a code for drawing a circle:

For Angle = 0 To 360 Step 1 / 100
    SetPixelV Picture1.hdc, Round(CenterX + Cos((Angle * (3.1415926 / 180))) * Radius), Round(CenterY + Sin((Angle * (3.1415926 / 180))) * Radius), RGB(0, 255, 0)
Next Angle

but now i want to fill it using setpixelv but how?
if i do for i = 0 to radius, it draws too many or too few times at each pixel...so i have to change the step.

is there any way to know exactly how many pixels that will be used, or do i have to do this another way?