People who have received a U.S. savings bond as a child, as a basic investor or as an employee may wonder years later how much that bond is worth. The face value on a paper version of a U.S. bond tends to be misleading. It typically represents the value of the bond after 30 years have expired. However, you don't have to be left in the dark. For example, if you have a bond from 1994, there is a method for determining the value to date.
Series EE Bonds

As the most common savings bonds issued by the U.S. government, the paper version of EE bonds reflects a face value the bond will be worth after 20 years. So if the bond says $100 on the front, it sells originally for $50. In 1994, U.S. Series EE bonds were for sale in such a manner. They sold in face value denominations of $100, $200, and $500, all of which followed the doubling rule after the 20 years expired.
Valuation

The Series EE bonds grow their value with interest. The interest earned is determined by an interest rate that has been fixed since May 2005. Prior to that time, the interest rate floated. However it fluctuated since 1994, the U.S. Treasury committed that such bonds would at least double in value in 20 years (some doubled within 17 or 18 years). This amount will be reached by 2014, 20 years later. The EE bond will only earn interest for 30 years total, at which time the earning stops, typically forcing the holder to cash it out.
Doing the Math on Paper

If you're keen on math, you could calculate the growth on a 1994 bond by finding the tables that show the interest rates each year since 1994 applied to that bond. You compound the bond purchase value for each year with each different rate until you get to the present. After a significant amount of multiplying, the result will be your currentday value. However, there's an easier way.
Just Ask the Treasury's Online Calculator

The U.S. Treasury provides a bond calculator at its Savings Bond website. Input your bond information, serial number, and denomination, and with this information, the calculator references the rate tables on file specifying each bond value to date. The answer gives you the current value of your bond updated periodically. This will change over time as the tables get updated and the online calculator references new material. You need a computer and an Internet connection to get access.