How CDs Work
A Certificate of Deposit (CD) is a savings product offered by banks and credit unions. You deposit a fixed amount for a fixed term (e.g., 6 months, 1 year, 5 years) and earn a guaranteed interest rate. In exchange for locking up your money, CDs typically offer higher rates than regular savings accounts. Early withdrawal usually incurs a penalty.
The Compound Interest Formula
Where:
A = Final amount
P = Principal (initial deposit)
r = Annual interest rate (decimal)
n = Compounding periods per year
t = Time in years
Frequently Asked Questions
Does compounding frequency matter much?â–¾
For most CD rates, the difference between daily and monthly compounding is minimal. However, with higher rates and longer terms, daily compounding can earn you slightly more. Most banks compound daily or monthly.
What happens if I withdraw early?â–¾
Early withdrawal penalties vary by bank and term length. Common penalties range from 3 months of interest (for short-term CDs) to 12 months or more (for longer terms). Some banks offer no-penalty CDs with slightly lower rates.
What is a CD ladder strategy?â–¾
A CD ladder splits your total deposit across multiple CDs with staggered maturity dates (e.g., 1-year, 2-year, 3-year). As each CD matures, you can access the funds or reinvest. This provides regular liquidity while still earning higher long-term rates.
Are CDs a good investment right now?â–¾
CDs are ideal for money you want to keep safe and earn a guaranteed return on. They are best when rates are high and you expect rates to fall (locking in today's rate). They are not ideal for long-term growth, as stocks historically outperform CDs over decades. CDs are FDIC-insured up to $250,000 per depositor, per bank.
Calclypso Editorial Team
Reviewed by certified financial professionals. Last updated: April 2026. CD interest calculations use standard compound interest formulas. Actual returns may vary slightly due to bank-specific compounding methods and day-count conventions.