GST Free Portion Calculation
There may be occasions where a component of an invoice is GST Free but is not itemised and you need to calculate it manually, this page will explain how to do so.
Total on Invoice = $546. GST for that amount should be $49.63
GST on Invoice = $32. GST amounts don't add up, that means there is a portion of the total that is GST Free.
To calculate that amount, use the following equation.
GST x 11 = a
Invoice total - a = b
- GST = GST as written on invoice
- Invoice total = Total as written on invoice
- a = portion that has GST
- b = portion that is GST free
Total on Invoice = $546
GST = $32
$32 x 11 = $352
$546 - $352 = $194
$352 = Portion with GST
$194 = Portion without GST (GST Free)