One. It needs to be a first class stamp and the letter needs to be one ounce or less.
if it weighs an ounce or less, three stamps.
2 stamps. ! stamp is good for up to one ounce, 21 cents for second ounce.
One ounce letter, one stamp.
A regular letter to the Ukraine needs to be sent as First Class Mail - International and will require International Rate Stamps. You can not use regular US stamps, you must purchase and use International Rate Stamps.The number of stamps will depend on the weight of the letter. A 1 ounce letter will cost $1.15 (as of April 2015). A 2 ounce letter will cost $2.14, 3 ounces costs $3.12, and 3.5 ounces costs $4.11.
One, plus a 21-cent extra-ounce stamp.
One forever stamps pays for up to a one ounce letter. BTW, I think .06 oz. is impossibly light. Maybe you meant .6 or something else.
One 44 cent stamps pays for a letter weighing up to one ounce.
In the US it would cost 61 cents to mail a two ounce letter. It is 44 cents for the first ounce and 17 cents for each additional ounce.
It will cost $1.29 to mail a 6 ounce letter. The first ounce is 44 cents. Each additional ounce is 17 cents.
3 it is 1 stamp/ounce as a rule of thumb
A (1) ounce letter is $0.44 cents. (2) ounce letter $0.61 cents. (3) ounce letter $0.78 cents. (3.5) ounce letter $0.95 cents. I would personally put (2) $0.44 cent stamps just to make sure, or take it to the post office to weigh it.