GST Calculator

This calculator adds or removes Goods and Services Tax from a price, with preset rates for Canada, Australia, New Zealand, India, Singapore, and a custom option for any other rate.

To add tax, it multiplies the price by the rate and adds that on top. To remove tax from a total that already includes GST, it divides by (1 + rate) to back out the original pre-tax price.

Example: A $100 item with 5% Canadian GST becomes $105 total. If instead you have a $105 receipt that already includes 5% GST, the pre-tax price works out to $100 and the tax portion is $5.