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CD Calculator: 10,450.00 maturity value. 10,000 at 4.5% APY for 12 months · interest 450.00 · rough 3-month penalty 112.50 leaves 10,337.50 if applied at term-end value · comparison at 4% APY: 10,400.00 (+50.00 difference)
Formula applied
The exact method behind this answer
CalculationTime keeps the method visible so the number can be checked instead of blindly trusted.
Ending balance = opening deposit × (1 + APY decimal)^(term months ÷ 12). Interest earned = ending balance − opening deposit. Rough early withdrawal penalty = opening deposit × APY decimal × penalty months ÷ 12. Comparison balance uses the same formula with the comparison APY.- Apply the formulaEnding balance = opening deposit × (1 + APY decimal)^(term months ÷ 12). Interest earned = ending balance − opening deposit. Rough early withdrawal penalty = opening deposit × APY decimal × penalty months ÷ 12. Comparison balance uses the same formula with the comparison APY.10,450.00 maturity value10,000 at 4.5% APY for 12 months · interest 450.00 · rough 3-month penalty 112.50 leaves 10,337.50 if applied at term-end value · comparison at 4% APY: 10,400.00 (+50.00 difference)
Your live breakdown
Current inputs in the calculation
These values come from the controls above and update when the calculator changes.
- Opening deposit
- 10,000 money
Amount placed into the certificate of deposit at the start.- Published APY
- 4.5 %
Use the bank’s annual percentage yield, not the nominal interest rate, when APY is what the offer publishes.- CD term
- 12 months
Length of the certificate in months.- Early withdrawal penalty
- 3 months of interest
Optional rough penalty expressed as months of simple interest. Check the actual account disclosure.- Comparison APY
- 4 %
Optional competing CD or savings APY for the same deposit and term.
Resulting answer
10,450.00 maturity value
10,000 at 4.5% APY for 12 months · interest 450.00 · rough 3-month penalty 112.50 leaves 10,337.50 if applied at term-end value · comparison at 4% APY: 10,400.00 (+50.00 difference)
- Answer
- 10,450.00 maturity value
- Live support
- 10,000 at 4.5% APY for 12 months · interest 450.00 · rough 3-month penalty 112.50 leaves 10,337.50 if applied at term-end value · comparison at 4% APY: 10,400.00 (+50.00 difference)
Assumptions used
What this answer assumes
Best for savings certificates, term deposits, classroom compound-interest worksheets and bank-offer comparisons where APY, term and penalty assumptions need to stay visible.
- The APY is entered as an annual percentage yield and is assumed to stay constant for the full CD term.
- The calculation assumes one opening deposit with no additional deposits, withdrawals, fees, taxes, brokered-CD rules or rate step-ups.
- Term length is entered in months and converted to years by dividing by 12.
- The early-withdrawal penalty line is a rough months-of-interest planning note, not a bank-specific legal calculation.
- For real account decisions, confirm APY, compounding, maturity date, renewal rules, insurance coverage, penalties and taxes in the official provider disclosure.
Master’s Tip
How to use the result well
Master’s Tip: write the maturity date, renewal rule and early-withdrawal penalty on the printed record. A strong APY can be weakened by auto-renewal timing, liquidity needs or penalties that are not obvious in the headline rate.
Printable record
What belongs in the saved calculation
Save the inputs, result, formula, assumptions, page URL and date together so the calculation can be reviewed later.
- Opening deposit
- 10,000 money
Amount placed into the certificate of deposit at the start.- Published APY
- 4.5 %
Use the bank’s annual percentage yield, not the nominal interest rate, when APY is what the offer publishes.- CD term
- 12 months
Length of the certificate in months.- Early withdrawal penalty
- 3 months of interest
Optional rough penalty expressed as months of simple interest. Check the actual account disclosure.