Tipping is customary but not mandatory in Canada. For a full-day group tour (8–10 hours), $15–$25 per guest is typical. For a private tour, 10–15% of the tour cost is standard, more for exceptional service.
Drivers and guides are often two different people on group tours — both rely on tips, and many companies pool them. A single tip handed to the guide at the end of the day is normal; they will split with the driver.
Beyond the cash: a five-star review with the guide's name in it is genuinely valuable — it directly affects their bookings. A photo emailed afterward, or a quick thank-you note, is remembered.
If the service was poor, do not tip out of guilt. Tell the operator instead — that is how things get fixed.