I just weighed my letter size envelope with 12 standard pieces of paper folded inside and it was 2 ounces. According to USPS.com, the cost is $.64. I am using 2 forever stamps to get the letter on its way.
If you can't fold the paper like a normal letter, go to USPS.com where they provide a convenient postage price calculater.
Check the US Postal Service Website for current rates. As of September 2007: For up to 1 ounce, if you mail it in a #10 envelope, it is 41 cents. If you mail it in a 9 X 12 inch envelope it is 80 cents. Note that the USPS rates page suggests that 1 ounce is aprox. equivalent to Three 8.5x11 inch letter pages plus the weight of the envelope.
As of October 2011, Canada Post domestic lettermail costs $0.59
first class mail up to 1 ounce is .42
It takes enough stamps that total $.42 to post a letter in the US. That is what the US Postal Service charges even from city to city or state to state. They raised the rate not long ago. There are $.42 stamps available for purchase.
In the US, the amount of postage is the same for mailing a letter anywhere within the US. Not sure is additional charge for mailing to Hawaii.
Only one stamp is needed to send a letter from state to state within the United States. The current cost of a stamp is 49 cents.
It depends entirely on the value of the stamps. In 2010, a standard letter currently requires a stamp or stamps to the value of 60c within Australia.
1
Domestic postage for a standard letter is now .57 each, .60 with tax. These stamps do not have the rate on them, and never expire. This change was done as of Jan 11, 2010.
One, provided it has a high enough value. All ordinary first-class letter mail between two points within the US, whether across the street or across the country, is charged at the same rate.
It reqires 49 cents in postage to send a first class letter within the U.S.
If the mail piece is within normal letter regulations it should only cost a standard stamp (.44 cents). If it is a little heavier than normal, you might want to try using two stamps or .68 cents worth of stamps
41¢, the same as any 1st-class letter within the U.S.