About This Calculator
Use this free CD interest calculator to estimate your maturity value based on principal, APY, term length, and compounding frequency. It supports compounded daily, compounded monthly, and more to ensure your savings calculations are precise.
How to Calculate CD Interest
- Enter your initial deposit (principal), APY, term in months, and compounding (monthly/quarterly/annual)
- Click Calculate or adjust inputs to see instant results
- Review maturity value, total interest earned, and effective annual yield
Compatible with Major US Banks
Our calculator is designed to handle the compounding frequencies and terms offered by top financial institutions. Whether you have a CD with Navy Federal Credit Union, Chase Bank, Wells Fargo, Bank of America, or Citibank, simply enter your APY and term to verify your interest earnings. We support daily, monthly, and quarterly compounding options used by these banks.
CD vs. Savings Account: Which is Better?
Deciding between a Certificate of Deposit and a High-Yield Savings Account (HYSA)?
- Returns: CDs generally offer higher, fixed interest rates, whereas savings rates are variable and can drop.
- Liquidity: Savings accounts allow easy access to cash. CDs require you to lock your money for a set term to earn that premium rate.
- Best For: Use a CD for long-term goals where you want to guarantee your return. Use a savings account for your emergency fund.
Formula and Method
We use your APY and compounding to estimate maturity value.
- Periods per year (n): Monthly = 12, Quarterly = 4, Annually = 1
- Periodic rate (r): r = (1 + APY)^(1/n) - 1
- Total periods: periods = (months / 12) * n (can be fractional)
- Maturity value: M = P * (1 + r)^(periods)
- Interest earned: I = M - P
We round currency to the nearest cent to reflect real-world statements.
Worked Example
Principal P = $10,000; APY = 5.00%; Term = 12 months; Compounding = Monthly.
- n = 12; r = (1 + 0.05)^(1/12) - 1 ≈ 0.004074
- periods = (12 / 12) * 12 = 12
- Maturity: M = 10000 * (1 + 0.004074)^12 ≈ $10,511.62
- Interest: I ≈ $511.62
Note: Daily compounding would yield slightly more, but APY already summarizes compounding.
Why Use This CD Calculator?
- Free: Completely free—no signup, no ads required to calculate
- Private: Runs 100% in your browser. We don’t store your inputs
- Fast: Instant results as you type
- Simple: Clean, mobile-first UI
- Mobile-Friendly: Optimized for small screens and touch
Daily vs Monthly Compounding Support
We estimate maturity value using your APY and compounding frequency. Our engine correctly handles compounded daily, compounded monthly, and compounded quarterly logic to match bank statements. For non-integer months, the calculation prorates the final period. Results are rounded to the nearest cent for clarity.
Common Pitfalls
- APY vs APR: APY includes compounding and is appropriate for CDs.
- Partial months/years: We prorate using fractional periods for a closer estimate.
- Daily compounding: Actual results may differ slightly; APY normalizes most differences.
- Taxes and penalties: This tool shows pre-tax estimates and excludes early withdrawal penalties.
Methodology & Calculation Notes
- Compounding formula: M = P × (1 + r/m)^(m×t), with APY normalized to frequency.
- APR → APY: When APR mode is selected, we convert to APY using the chosen compounding frequency.
- Rounding: Monetary values round to the nearest cent; rates shown to two decimals by default.
- Fractional periods: For non-integer terms, we use fractional exponents for compounding.
- Schedule: The accrual schedule is derived period-by-period and may differ slightly from bank statements.
- Taxes: After-tax figures use your input tax rate as a simple estimate and are not tax advice.
Early Withdrawal: Should You Cash Out?
- Estimate what you've earned so far and the penalty per your bank's policy (e.g., 3 or 6 months of interest).
- Compute net interest (earned minus penalty) and your refund amount.
- For the remaining term, calculate the break-even APY: if a new CD's APY exceeds this, switching could make sense. Otherwise, holding likely yields more.
Tip: Penalties are often based on interest, not principal—our calculator approximates typical policies.
CD Key Terms & Definitions
- APY (Annual Percentage Yield): The real rate of return earned on an investment, taking into account the effect of compounding interest.
- APR (Annual Percentage Rate): The annual rate of interest without taking compounding into account.
- Principal: The initial amount of money you deposit into the CD.
- Maturity Date: The specific date when the CD term ends and you can withdraw your funds without penalty.