Weight per bean ca 130mg from here
One needs approx. 15g coffee per 250ml water, corresponding to 115beans per cup.
A 237ml serving of coffee contains 95mg caffeine (USDA), which would be 830ug / bean (I've read other sources saying about 1mg/bean). Note that this is extracted values, whole beans can contain as much as 7mg see here
In your 145g bag, let's say 2/3 of the weight, e.g. 100g, is coffee beans, which corresponds to 770 beans, which would be 640mg to 5.2g(!) of caffeine.
However it's not clear how much extraction occurs the human digestion system at body temperature, especially as you will not chew the beans as finely as a coffee grinder.
I think you're just going to have to rely on seeing how you feel after a certain number of beans, as caffeine tolerance varies so much per individual.