Future Value Calculator
Calculate the future value of an investment with an initial deposit, regular contributions, and compound interest
By Waqar Mushtaq · Last updated:
Future value tells you what an investment or savings balance will grow to after a set number of years, once compound interest and any regular contributions are factored in. Unlike a plain compound interest calculator, which only grows a single lump sum, this calculator also handles the much more common real-world scenario of adding a fixed amount every period — a 401(k) contribution from every paycheck, a monthly transfer into a high-yield savings account, or a recurring brokerage deposit — alongside an optional starting balance.
How Future Value With Contributions Works
O(1) calculationFV = future value · P = initial deposit · PMT = contribution per period · i = rate per period (annual rate ÷ compounds per year) · n = total number of periods
Annuity due (contributions at the start of each period) earns one extra period of interest
The total future value is the sum of two pieces that grow independently and are simply added together: the initial deposit compounding on its own (the first term), plus the future value of the series of regular contributions (the second term, a standard future value of an annuity formula).
Example: $1,000 initial deposit, $100/month contribution, 6% annual interest compounded monthly, for 10 years:
- Rate per period: i = 0.06 / 12 = 0.005
- Total periods: n = 12 × 10 = 120
- Growth from the initial deposit: $1,000 × (1.005)^120 = $1,819.40
- Growth from contributions: $100 × [((1.005)^120 − 1) / 0.005] = $16,387.93
- Future value: $1,819.40 + $16,387.93 = $18,207.33
- Total contributed over 10 years: $1,000 + ($100 × 120) = $13,000, meaning $5,207.33 of the final balance is interest.
Contribution timing matters: if contributions happen at the beginning of each period (an annuity due) instead of the end (an ordinary annuity — the more common default for paycheck-driven savings), each contribution earns one extra period of interest, making the annuity due formula multiply the contribution total by an additional (1 + i).
Use Cases
Retirement Account Projections
Estimate how a 401(k), IRA, or similar account will grow given your current balance, a fixed contribution per paycheck, and an assumed rate of return — far more realistic than a lump-sum-only projection.
Automatic Savings Plans
See how a recurring monthly transfer into a high-yield savings account or CD ladder adds up over several years, alongside whatever balance you're already starting with.
College Savings (529 Plans)
Project how regular contributions to an education savings account, combined with any initial deposit, will grow by the time tuition is due.
Comparing Contribution Timing
See concretely how much extra beginning-of-period contributions (annuity due) are worth compared to end-of-period contributions (ordinary annuity) over your specific timeline and rate.
Frequently Asked Questions
What's the difference between this and the Compound Interest Calculator?
The Compound Interest Calculator grows a single initial deposit with no further additions. This Future Value Calculator adds regular periodic contributions on top of that initial deposit — a much more realistic model for a retirement account or savings plan you're actively contributing to.
Should I choose "end of period" or "beginning of period" for contribution timing?
Most real-world contributions — a 401(k) deduction from your paycheck, an automatic transfer at the end of the month — happen at the end of the period, so "end of period" (an ordinary annuity) is the more common and typically more conservative choice. "Beginning of period" (an annuity due) assumes each contribution is deposited right at the start of the period, giving it one extra period of interest and a slightly higher total.
Why does compounding frequency also apply to my contributions?
This calculator assumes contributions happen at the same frequency as compounding — e.g. monthly compounding pairs with monthly contributions. This matches how most real accounts work (a monthly-compounding savings account with a monthly auto-transfer) and keeps the formula exact; if your contribution schedule genuinely differs from your compounding schedule, treat the result as a close approximation rather than an exact figure.
What if I only want to see growth from an initial deposit, with no contributions?
Set "Regular Contribution" to $0. The calculator will show growth from your initial deposit alone, matching the compound interest formula exactly.
Does this account for inflation, taxes, or investment fees?
No — this calculator projects nominal future value based on a fixed interest rate you supply. It doesn't model inflation (which erodes purchasing power), taxes on gains, or account/fund fees. For a real investment decision, consider those separately or use a rate of return that's already net of fees.
Methodology
The formula above is implemented as a standalone module covered by unit tests, so its worked examples are re-checked on every change to the site. It is verified against the authoritative sources listed below.
Not financial advice. This calculator is a general informational tool and cannot account for your individual circumstances. See the terms of use.
Maintained by Waqar Mushtaq. Spotted a result that looks wrong? Report it and it becomes a failing test.