Updated August 2026
EE and I bonds are the two savings bond series still sold today, and they're easy to mix up in a mixed stack — both come in similar paper formats and similar-looking certificates. The series letter printed on the bond settles which one you're holding, but the two behave very differently once you know that. Here's the practical comparison.
| Series EE | Series I | |
|---|---|---|
| First sold | January 1980 | September 1998 |
| Paper purchase price | Half of face value | Full face value |
| Rate type | Fixed for life (bonds since May 2005) | Composite: fixed + inflation, resets every 6 months |
| Special guarantee | Doubles in value at 20 years (bonds since June 2003) | None — value tracks the composite rate directly |
| Can value ever fall? | No | No — composite rate floors at zero |
| Early-redemption penalty | Last 3 months' interest, under 5 years | Same — last 3 months' interest, under 5 years |
| Final maturity | 30 years | 30 years |
An EE bond's rate is set once and stays put — predictable, but it means older EE bonds can be earning a rate far below or above what's available today. An I bond's rate is a moving target: a fixed portion set at purchase, plus an inflation adjustment that resets every May and November for every I bond outstanding, regardless of issue date. That makes I bonds behave more like an inflation hedge, and EE bonds more like a fixed-rate savings instrument with a guaranteed floor at the 20-year mark. See how savings bond interest works for the mechanics behind both.
There's no universal answer — it depends entirely on the specific issue date and the rate environment at the time. An EE bond bought right before the 2003 doubling-guarantee rule and held past 20 years can look extremely strong relative to its purchase price. An I bond bought during a high-inflation stretch (2021–2022, for instance) can also have grown quickly. Denomination and series alone won't tell you which is worth more — issue date is what actually determines it, and the only reliable way to compare two specific bonds is to run each through the calculator.
Look at the top of the certificate: it reads "Series EE" or "Series I" directly. If the printing has faded on an old bond, the design and color scheme also differ slightly by series and era, but the printed series letter is the only detail to rely on for calculating value correctly.
Can I convert an EE bond to an I bond, or vice versa? No — each bond keeps the series and terms it was issued with for its entire life.
Which is better to buy today? That's a purchase decision, not something this site advises on — see current rates and purchase details at treasurydirect.gov. This calculator is built for valuing bonds you already hold.