As said above, use Canada Post's estimation tool. Also important is to get an inexpensive scale like the one suggested at the Wirecutter.
https://www.nytimes.com/wirecutter/r...kitchen-scale/
At home, we use the recommended scale and CP's estimation tool and have never gotten the shipping price wrong.
If you want to save on shipping, get a Canada Post business account. My wife has one mostly for shipping her Cabbage Patch Kids dolls. The account is free, shipping costs are cheaper than regular price off-the-bat and you get more discounts the more you ship.
