My brain is a gloopy mess
I have changed the calculation
From "GST" as: ([Price] * [Quantity]) * 0.125
To "GST" as: ([Price] * [Quantity]) /9
as it was adding the gst to the total & 12.5% works out to be a ninth when inclusive.
But as I said above the GST only shows in the condition area dropdown menu & doesn't show in the calculation area dropdown menu.
So I have used "Based on column subtotal" 'subtotal of column' "price" - it now shows the GST correctly(well sort of) but the total price now shows double the amount in my page.
For example it shows. One item subtotal of $19.95 then GST of $2.22 this is correct
then the total is $39.90 which is double & incorrect.
Any other ideas?