What is the value of a US half dollar?

Answer 1

You need to provide much more information. Half dollars have been made for over two centuries at about a half-dozen mints so at a bare minimum you need to identify its date, condition, and mint mark.

If it's a current (1971-present) Kennedy half, it's made of copper-nickel, not silver, and is worth exactly 50 cents unless it's a proof coin in the original package.

If it's dated 1965 to 1969 it's made of 40% silver and is worth about $2.75 to $3.00 as of 02/2010.

If it's older than that it's made of 90% silver and its value is very dependent on its date and mint mark. If your coin is dated 1964 or earlier please post a new and more specific question. This is especially important for the Ben Franklin coins 1948-1963 and the earlier Liberty Walking halves.

Anywhere from 50 cents up. Almost any Kennedy half made since 1971 that has been circulated even a little bit is only worth face value. Most of them are available in uncirculated condition for less than $2. Anything older is worth at least the value of the silver it contains. Coins in excellent condition may be worth more than their silver value.