5 cm wide?
15cm tall?
I suspect you're extracting those numbers from thin air. Or your hands are deceptively freakish.

I think you've got a pretty major margin of error there or so. But maybe your hands are deceptively freakish.
V = (PI) * (h) * (r
2)
Diameter / 2 = Radius
Diameter = 5cm :: Radius = 2.5cm
Height = 15cm
Height * PI ~= 47.124
2.5
2 = 6.25
47.124 * 6.25 ~ 294.525 cubic centimeters = 294.5 ml
Wow. A third of a liter. Definitely freakishly large hands...
If you want to pull out a ruler and measure the bottle, then calculating the volume becomes a tad more ... precise.
