The Future Value Investment Account Calculator projects what a single deposit into an account, a savings account, certificate of deposit, or brokerage cash position, grows to after a chosen number of years at a stated interest rate and compounding frequency. Enter the deposit amount, the annual rate, the term and how often the account compounds, and the calculator returns the ending balance.
Real accounts advertise their compounding schedule in the fine print, and that schedule genuinely affects how much a deposit actually earns over time, even when the headline annual rate looks identical across two different products. This calculator is framed around that practical account-comparison question rather than the abstract formula alone.
*These results are estimates for information only, not investment advice.*
Project a single account deposit forward
An account balance funded by a single deposit, with no further contributions, grows according to Future Value = Deposit x (1 + r/n)^(n x t), where r is the annual rate the account pays, n is how many times per year it compounds, and t is the number of years the deposit stays in the account.
Take a $10,000 deposit into an account paying a 5% annual rate, compounded monthly (a common schedule for savings accounts and many CDs), left untouched for 10 years. Running those figures through the formula produces an ending balance of approximately $16,470.09, meaning the account earns about $6,470.09 in interest over the decade with no additional deposits at all.
Compare accounts that compound on different schedules
Two accounts can advertise the identical 5% annual rate and still pay out differently over time if one compounds monthly and the other compounds annually.
On the $10,000, 10-year example above, monthly compounding reaches $16,470.09, while annual compounding on the same rate and term reaches only $16,288.95, a difference of about $181.14 attributable entirely to how often the account credits interest, not to any difference in the stated rate.
This is exactly the kind of detail that a headline "5% APY" or "5% interest rate" label does not always make obvious on its own, and checking an account's actual compounding schedule against another option's schedule, using this calculator, is a quick way to see if the difference is meaningful for a given deposit size and term.
See how deposit size and term change the outcome
Because this projection scales linearly with deposit size, doubling a deposit into the same account exactly doubles the resulting future value, holding the rate, term and compounding frequency constant.
Extending the term, by contrast, compounds growth exponentially rather than linearly, so leaving a deposit in an account for 20 years instead of 10 produces considerably more than double the ending balance at the same rate.
The Future Value Investment Account Calculator makes it easy to test a range of deposit sizes and terms against a specific account's stated rate and compounding schedule to see how the ending balance responds to each change independently.
Use this before locking money into a term account
Certificates of deposit and other term-locked accounts typically state their rate and compounding schedule clearly at the time of deposit, since the terms do not change once the money is committed for the stated period.
Running the account's actual advertised rate, term and compounding frequency through this calculator before depositing gives a clear expectation of the ending balance, which is useful for comparing against alternative accounts or investment options before committing funds for a fixed period.
For accounts with variable or promotional rates that may change during the term, this projection reflects only what the current stated rate would produce if it held constant for the entire period, which real variable-rate accounts often do not guarantee.
Know what this calculation does not include
This calculation assumes a single deposit with no further contributions or withdrawals, a rate that stays fixed for the entire term, and no fees, account maintenance charges or taxes deducted from the growing balance.
Real accounts may charge fees that reduce net growth, and interest earned in a taxable account is generally subject to income tax in the year it is credited, which this projection does not account for.
Use the Future Value Investment Account Calculator to compare the pure mechanics of different rates and compounding schedules. For a full picture of net, after-tax and after-fee growth, factor those specific account terms in separately.
Frequently asked questions
How much does a $10,000 deposit grow to in a 5% account over 10 years?
A $10,000 deposit into an account paying 5% annual interest, compounded monthly, grows to approximately $16,470.09 over 10 years. Compounded annually instead, the same deposit and rate would grow to $16,288.95.
Why do two accounts with the same rate pay different amounts?
Two accounts with the same stated annual rate can pay different amounts if they compound on different schedules. More frequent compounding, such as monthly versus annual, produces a larger ending balance for the same rate and term, since interest is credited and reinvested more often.
Does deposit size change the future value proportionally?
Yes, the future value scales linearly with deposit size. Doubling a deposit into the same account, at the same rate, term and compounding frequency, exactly doubles the resulting ending balance.
Does this calculator account for taxes on interest earned?
No, this calculation projects gross growth before taxes. Interest earned in most taxable accounts is subject to income tax in the year it is credited, which would reduce the actual after-tax balance below what this calculator shows.
Is this projection reliable for a variable-rate account?
Only as a snapshot based on the current rate. Variable-rate accounts can change their rate during the term, so this projection reflects what the balance would be only if the current stated rate held constant for the entire period, which is not guaranteed for variable-rate products.
Summary
The Future Value Investment Account Calculator projects a single account deposit forward using Future Value = Deposit x (1 + r/n)^(n x t), letting the compounding frequency be matched to a real account's actual schedule.
A $10,000 deposit at 5% compounded monthly grows to approximately $16,470.09 over 10 years, versus $16,288.95 with annual compounding, a difference worth checking when comparing accounts that advertise the same headline rate.
This projection excludes fees and taxes. Figures shown are estimates, not investment advice.