(Section 49(2))

For the purpose of determining the deductible input tax under subsection (2) of section 49, the following formula shall apply

A x B/C where

A is the total amount of input tax for the period that is not directly attributable to taxable or exempt supplies;
B is the total amount of taxable supplies made by the taxable person during the period; and
C is the total amount of all supplies made by the taxable person during the period.