That online calculator uses the American WW system which is pointed differently. You could do with buying a calculator - do you know anyone who goes to classes who could get one for you? Or you could look on ebay but WW are tending to pull adverts from vendors selling WW stuff on there - you might get lucky though.
Worst case scenario, if you're good at maths, a quick and dirty method is to divide the calories by 70, divide the saturated fat by 4 and add the two results together.
e.g. if a food was 200 cals and 4g of sat fat, it would be 4 points (200/70 = 2.85; 4/4 = 1, thus 3.85 which rounds up to 4).