How do I find out how much GST was paid from a total sale ?

Question

I know I can go through all my receipts and add up the GST I paid, but that would take quite a while. Is there any way of getting the number based on a combined GST, PST and total sale number.

Answer 1

If you are in Quebec there is.  Take the Total all taxes in

Total X 100 / 107.5 = Amount Before QST

Take Amount before QST * 100 / 105 = Amount before GST

If you are in Ontario

Total  X 100 / 113

This gives you the total before both GST @ 5% and PST @ 8%.  

Simply calculate the GST amount and then the PST amount

Example

113 All Taxes in x 100 / 113 = 100.00 Total Before Taxes

100 * 5 % = 5.00 GST

100 * 8 % = 8.00 PST

Answer 2

My16paws shortcut should work in most cases, but let me add a caution.  Not everything you buy in Ontario will have GST and PST, some things like basic groceries have none of either, a few things like children's clothes have GST but no PST, etc. etc.  Worth going through a sample just to make sure you aren't spending much on items that do not have both.