The value of any coin depends on its date, mint mark, and condition. Without that information, it's not possible to give anything other than a very rough guide:
Circulated JFK halves:
1964 halves are made of 90% silver and are worth about 35% of the price of an ounce of silver (see your local paper's financial page)
1965-1969 halves are 40% silver and are worth about 18% of the price of an ounce of silver.
1971-current halves have no silver at all and are worth exactly 50 cents. Feel free to spend them.
90% and 40% silver halves are on average worth about 55 and 35% of the price of an ounce of silver, respectively. Extremely well-struck coins are worth more.
1971 and later halves can be worth $1.25 to $4.00 on average, but again, very well-struck ones can be worth more.
There are also some more valuable exceptions but a professional would need to inspect the coins in person.
In circulated condition the coins are worth about $2.50 each; uncirculated ones retail for $3 to $3.25. However if the price of silver changes again they will fluctuate in value accordingly.
Half dollars minted from 1965 to 1969 are only 40% silver so they are a lot less valuable than their earlier 90% silver counterparts.
It depends on the year. A 1964 half is 90% silver and worth a little over $10. Halves 1965-70 are 40% silver and worth just over $4. Anything 1971-present, including the 1776-1976 half, is worth 50 cents.
To find the value of an individual coin ask another question structuring it like the one below(be sure to fill in the <> with the correct information):
What is the value of a
Half a dollar
It depends very much on the coin's date. Please check the questions "What is the value of a <date> Kennedy half dollar?". E.g. if your coin is from 1969, look for "What is the value of a 1969 Kennedy half dollar?".
What is the value of this half dollar
No 1963 Kennedy half dollars exist. 1963 is the last year of the Franklin half dollar. 1964 is the first year for Kennedy.
Check that coin again. Kennedy wasn't put on the half dollar until 1964.
the 1972 Kennedy half dollar is worth 50 cents in circulated condition, or about a dollar in uncirculated condition
A 1969 silver Kennedy half dollar is worth $5 inn perfect condition. The value of the silver is worth $2.87.
The gold plating adds nothing to the value, it's just a half dollar.
If you got it in change, spend it. It's just a half dollar.
Sorry it only has face value.
50 cents, just spend it.
A US half dollar with a date of 1979 is a Kennedy half dollar not a liberty half dollar. The coin has no silver and is only face value.
It's a Franklin half dollar. The first Kennedy half was struck in 1964. 1961 is very common date, value is about $15.00.
The 1969 Kennedy half dollar is only 40% silver with a value about $3.25
The 1968 Kennedy half dollar is only 40% silver and has a value of about $4.00.
A Mint State 1971 Kennedy has a retail value of $1.00-$2.00
For a circulated 1966 Kennedy half the value is only for silver about $1.00
The exact value of a Kennedy half dollar is actually dependent on a number of factors. Some of these factors would be the exact date and condition of the coin.
1965 to 1969 Kennedy half dollars were all struck in 40% silver and have a bullion value of about $2.00
If you mean a 1998 Kennedy half dollar, the coin has no silver in it and is worth face value.