It only takes a single stamp. But it does have to be the correct denomination. Currently the rate for one ounce of First Class Mail is 44 cents to anyplace in the US.
One.
6
1 first class stamp
One, as long as it is 45 cents and the letter is 1 ounce or lower.
One first class stamp is all that's needed.
All you need is ONE first class postage stamp. Provided that it's only a letter.
For a regular letter? Just one.
Ask at a post office in USA !
Just 1. Hawaii is zone 8.
As of February 2012, there are 629,011 food stamp recipients in the state of Oklahoma.
A single First Class stamp is adequate for a one ounce regular letter.
I depends on how much the letter weighs, 1 First Class stamp is good for 1 ounce.