The postage for a letter sized piece is .90 cents US up to the first ounce.
No, it will not be sufficient postage.
The rate is $1.82.
56p for a standard letter (September 2009)
Postage to Europe from the US is 98 cents for a one-ounce letter.
Is it first or second class?
Yes, at least in the UK, you can post any letter or parcel first class provided you pay the correct postage charge for the size/weight of the letter/package.
As of 1/1/11, $0.98 for first class from US to Australia, same as to the UK.
39 pence as of 30 April 2009.
1st Class regular envelope = $.94 GoTo http://ircalc.usps.gov/ to see rates on other
US Postal Service first class postage would be $3.96 ... see Related Link for more details.
In the UK a standard first class Royal Mail stamp in December 2013 is 60p.
It varies according to the weight, type of letter or parcel and the speed you want it delivered. Follow the related link to The Post Office - fill in the details of your postal item, and it will tell you the postage you'll pay.