First Class US Postal Service cost for a 4 ounce envelope to Canada would be $1.81. You can read more details at the Related Link below ...
How much does it cost to send a padded envelope to canada weighing 9 ounces
The cost is 75 cents for an ordinary letter from the US to Canada.
how much postage for a 9x12 envelope weighing 6.6 ounces
how much did a postage stamp cost in 2016
First class 1 ounce is 2 cents. Two ounces in 3 cents.
First Class postage to Canada would be $1.50 as long as the letter is not over 3.5 ounces ... for heavier letters or packages, see the Related Link below.
How much is it to send a birthday card from Toronto area to London, England?
11.5 oz
According to Canada Post's site, which I just looked up, it is $0.52.
how much postage required for a 9x12 envelope weighing 4.6 ounces
How much is it to ship something from virginia canada
As of Jan. '09 - in Canada - $0.54, to USA - $0.98, for international - $1.65.