Visitors from tax-inclusive countries often meet Canadian sales tax at the card terminal rather than on the shelf. The federal GST is 5%, some provinces combine it with their tax as HST, and others add a separate PST or QST. The destination, not the maple leaf on the receipt, decides the arithmetic.
Five destinations, five versions of C$100
Build the total before reaching the terminal
GST, HST, PST and QST in one breath
GST is the federal Goods and Services Tax. HST is a province's harmonized federal and provincial tax shown as one rate. British Columbia and several other provinces keep GST and PST as separate lines. Quebec uses GST plus QST. The receipt may look different even when the combined percentage is similar.
The grocery basket has its own logic
Basic groceries such as milk, bread and vegetables are generally zero-rated for GST/HST. Prepared meals, restaurant food, soft drinks, candy and many snack foods follow different rules. Two things eaten on the same bench can therefore have different tax treatment.
Accommodation can grow extra local lines
A hotel bill may carry GST or HST plus a provincial or municipal accommodation levy. Those local charges are not captured by a simple retail tax percentage. Read the full booking price and final invoice, especially when comparing a room with a short-term rental.
Do not memorize every province
Use the rate where the purchase is supplied and allow a little headroom in the wallet. Canada's official GST/HST calculator is a better final authority than an old screenshot, and provincial taxes can change independently.