A series EE U.S. savings bonds will earn interest for up to 30 years, at which point a bond reaches final maturity. Since May 2005, EE bonds have been issued earning a fixed rate of interest, so a final value can be fairly accurately determined with a couple of easy calculations. Older series EE bonds earn variable rates, which can change twice a year. The projected value of one of these bonds will be more of a ballpark figure.

## Understanding Series EE Bonds Maturity for Newer Bonds

For newer series EE bonds, issued after April 2005, start by looking up the interest rate for your savings bond if you do not already know the rate. Rates for new bonds are set every May 1st and November 1st by the U.S. Treasury. The rate for any savings bond can be found in the Redemption Tables available on the TreasuryDirect.gov website. Find the tables by typing "redemption tables" in the search bar across every page of the website.

Determine the month when your bond will double in value. Current issue series EE bonds are guaranteed to double in no longer than 20 years. At the time of publication, no savings bond has been issued earning a high enough interest rate to double sooner than 20 years. For example, a $1,000 savings bond with an initial cost of $500 issued in July 2006 will be worth the $1,000 in July 2026.

## Formula for Calculating Savings Bond Maturity

Multiply the interest rate times 11 and add one to obtain a multiplication factor to calculate the bond growth from year 20 to year 30. For example, if the bond is earning 3.2 percent, the multiplication is 0.032 times 11 equals 0.352 plus 1 equals 1.352. Now, multiply the factor times the bond's 20 year value to get an estimated 30 year value. The example $1,000 bond times the 1.352 gives an estimated maturity value of $1,352.

## EE Bond Calculator for Older Savings Bonds

Here, you'll need to calculate the date the bond will at least double in value. Guarantee value dates are based on the month of issue. Here are the guarantee times for bonds issued back to March 1993:

- March 1993 through April 1995: 18 years
- May 1995 through May 2003: 17 years
- June 2003 to the present: 20 years

For example, a bond issued in June 2000 will double its investment value – reach the denomination value – in June 2017.

Look up the current rate of interest being earned by your savings bond. At the time of publication, savings bonds issued from 1993 through April 2005 were earning between 3 and 4 percent.

## Formula for Older Bonds

Multiply your bond's guarantee / face value times the appropriate factor to obtain an estimated 30 year value. If the interest rate is close to 3 percent us a factor of 1.5. If the rate is closer to 3.5 percent, use 1.6 and if the rate is near 4 percent, use 1.7. Using the June 2000 bond with a face value of $1,000, the current rate is 3.4 percent. Multiply $1,000 times the 1.6 factor and the bond will be worth approximately $1,600 at the 30 year point.

## Things to Consider

Bear in mind that interest rates on savings bonds have been running at record low levels. If rates increase in the future, the values of savings bonds at maturity may be slightly higher than the calculated estimates. Paper series EE savings bonds are purchased for one-half of the face value. For example, $1,000 bond initially cost $500. The U.S. Treasury guarantees that it will double to face value in 20 years.

References

Tips

- At the time of publication, interest rates on savings bonds were at record low levels. If rates increase in the future, the values of savings bonds at maturity may be slightly higher than the calculated estimates.
- Paper series EE savings bonds are purchased for one-half of the face value. For example, $1,000 bond initially cost $500.

Writer Bio

Tim Plaehn has been writing financial, investment and trading articles and blogs since 2007. His work has appeared online at Seeking Alpha, Marketwatch.com and various other websites. Plaehn has a bachelor's degree in mathematics from the U.S. Air Force Academy.