assuming your soup can is a cylinder
volume of cylinder=hpir^2
diameter/2=radius
diameter=3.25
3.25/2=radius=1.625
h=4.25
r=1.625
so
volume=(4.25)(pi)(1.625^2)
volume=(4.25)(pi)(2.640625)
volume=11.22265625pi
if you aprox pi to 3.14 then
volume=11.2265625(3.14)
volume=35.239140625 in^3
so pick either
11.22265625pi in^3 or
35.239140625 in^3 or whichever is closest