CD Calculator
Calculate your Certificate of Deposit compound growth, total interest earned, and final maturity balance with daily, monthly, or annual compounding.
| Initial Principal Deposit | $10,000.00 |
| Effective Annual Yield (APY) | 5.13% APY |
| Base Interest Rate (APR) | 5.00% APR |
| Monthly Interest Payout Equivalent | $42.72 / mo |
How Certificates of Deposit (CDs) Work
A Certificate of Deposit (CD) is a low-risk savings account that pays a fixed interest rate in exchange for leaving your money untouched for an agreed-upon term length.
Unlike standard savings accounts where interest rates can fluctuate weekly based on Federal Reserve policy, a CD locks in your exact interest rate for the entire life of the investment.
The Mathematics of CD Compound Interest
Here are the mathematical formulas used to calculate future CD values and effective annual percentage yields:
Where:
A = Final Maturity Balance
P = Initial Principal Deposit
r = Annual Interest Rate in Decimal (e.g. 5% = 0.05)
n = Compounding Frequency per Year (Daily = 365, Monthly = 12)
t = Term Length in Years (e.g. 18 months = 1.5 years)
Total Interest Earned = A - P
APY = ((1 + (r / n))^n - 1) * 100
Step-by-Step Worked Calculation Example
Suppose you deposit $10,000 into a 1-Year CD at 5.00% APR compounded daily (365 times per year):
- Identify variables:
P = $10,000, r = 0.05, n = 365, t = 1.0 - Calculate daily rate:
r / n = 0.05 / 365 = 0.000136986 - Add 1 and raise to power:
(1.000136986)^365 = 1.051267 - Multiply by principal:
$10,000 * 1.051267 = $10,512.67 - Total Interest Earned:
$10,512.67 - $10,000 = $512.67 - Effective APY:
5.127% → 5.13% APY
Master CD Growth Reference Table
Estimated final interest earnings and total maturity balances across standard deposits and terms (compounded daily):
| Deposit Amount | 6-Month (5.10% APY) | 1-Year (4.85% APY) | 2-Year (4.25% APY) | 3-Year (4.00% APY) | 5-Year (3.75% APY) |
|---|---|---|---|---|---|
| $2,500 | +$63.50 ($2,563.50) | +$121.25 ($2,621.25) | +$217.20 ($2,717.20) | +$312.16 ($2,812.16) | +$505.28 ($3,005.28) |
| $5,000 | +$127.00 ($5,127.00) | +$242.50 ($5,242.50) | +$434.40 ($5,434.40) | +$624.32 ($5,624.32) | +$1,010.56 ($6,010.56) |
| $10,000 | +$254.00 ($10,254.00) | +$485.00 ($10,485.00) | +$868.80 ($10,868.80) | +$1,248.64 ($11,248.64) | +$2,021.12 ($12,021.12) |
| $25,000 | +$635.00 ($25,635.00) | +$1,212.50 ($26,212.50) | +$2,172.00 ($27,172.00) | +$3,121.60 ($28,121.60) | +$5,052.80 ($30,052.80) |
| $50,000 | +$1,270.00 ($51,270.00) | +$2,425.00 ($52,425.00) | +$4,344.00 ($54,344.00) | +$6,243.20 ($56,243.20) | +$10,105.60 ($60,105.60) |
| $100,000 | +$2,540.00 ($102,540.00) | +$4,850.00 ($104,850.00) | +$8,688.00 ($108,688.00) | +$12,486.40 ($112,486.40) | +$20,211.20 ($120,211.20) |
How to Build a CD Ladder for Consistent Liquidity
A CD Ladder is a smart personal finance strategy where you divide your savings across multiple CDs with staggered maturity dates.
For example, if you have $20,000 to invest, you could put:
- $5,000 in a 3-month CD
- $5,000 in a 6-month CD
- $5,000 in a 9-month CD
- $5,000 in a 12-month CD
Every 3 months, one CD matures. You can either use the cash if needed or roll it into a new 12-month CD at the highest current rate, giving you regular cash access while maximizing interest.
5 Tips to Maximize Your CD Earnings
Frequently Asked Questions
A CD is a federally insured savings product where you lock in a lump sum deposit for a fixed period of time in exchange for a guaranteed interest rate that is usually higher than standard savings accounts.
Yes. Interest earned on a CD is considered ordinary income by the IRS and is taxable in the year it is credited to your account, even if you do not withdraw the funds until maturity. Your bank will issue a Form 1099-INT annually.
A No-Penalty CD allows you to withdraw your full balance and earned interest after the initial 7-day funding period without paying an early withdrawal fee. Rates are typically slightly lower than traditional locked CDs.
Traditional CDs only allow a single deposit when opening. However, some banks offer specialized "Add-On CDs" that allow additional periodic deposits throughout the term.
During the maturity grace period (typically 7 to 10 days), you can withdraw your principal and interest, transfer the funds to a checking/savings account, or roll the money into a new CD term.