One 28 cent stamp will do the job if you are mailing your card from within the US.
TWO US Forever stamps will suffice (USA to London post card)
No you cannot use US stamps. Items mailed must have the stamps of the country of origin on them. Most shops will be able to provide you with the appropriate stamps to use to mail with their cards, or visit their post office!
usually none, but if it needs a stamp, just one stamp is needed.
The price of a US postal service postcard stamp is 27 cents.
If this is just a post card you will only need the one stamp to mail it within the US.
In the US there were 7 cent stamps printed. Many of the definitive series of stamps included all denominations from 1 to 20 cents and then every 5 cents after that. And the Postcard rate for part of 1975 was 7 cents.
It depends where exactly you want to send it. Better ask at the post office. I pay 90 cents from NY to Eastern Europe.
It can cost about $4.60 with first class mail. It depends on the address that it is going to in China.
It only takes a single stamp. But it does have to be the correct denomination. Currently the rate for one ounce from the US to Ireland is 98 cents for a postcard or the first ounce of mail.
Sending Postcards with the USPSWhat Is a Postcard?A postcard is a rectangular mailer sent without an envelope.Sending a postcard is an extremely affordable way to communicate when you're using the U.S. Postal Service-regular postcards cost only $0.33 to mail!
Just go to usps.com and you'll find everything you need there :] pricing and everything