What This Calculator Does

When people compare CDs, the real question is usually not just the posted rate. It is whether locking the money longer is actually worth the extra return. This page is built to make that trade-off easier to compare.

It turns deposit amount, annual rate, and term into APY, maturity value, interest earned, average monthly interest, and effective yield. That gives you both the annualized view banks often market and the more practical "how much more money do I actually end up with" view.

When to Use It

• You are comparing short and long CD terms such as 3 months versus 1 year or longer.
• You want to turn a quoted annual rate into a dollar outcome.
• You want to compare yield and liquidity together instead of focusing only on one percentage.
• You want to narrow the field before reading full bank terms.

Inputs Explained

Deposit Amount

This is the principal you plan to place in the CD. It does not change APY itself, but it directly changes maturity value, total interest, and average monthly interest. If you keep principal constant while comparing several options, the differences are easier to interpret.

Annual Rate

This is the annual rate quoted by the product, so entering 4 means 4%. The current page converts that rate into a monthly rate for its internal estimate, which makes it good for consistent comparisons even though it does not mirror every bank's exact method.