Home › Finance Calculators › Future Value Calculator
Future Value Calculator
Use this free future value calculator to see what your money could grow to. Enter a starting lump sum, a monthly contribution, an annual interest rate, and how many years you plan to save, and it shows your future value, how much you put in, and how much of the result is interest earned.
Monthly contributions are spread evenly across each compounding period.
Balance over time
Your balance grows slowly at first, then faster as interest compounds. The chart updates live with your inputs.
How it works
Future value answers a simple question: if I put money aside today and keep adding to it, how much will I have later? The answer comes from compound interest — the interest you earn is added to your balance, and then that larger balance earns interest of its own. Over many years, the interest on the interest becomes the biggest part of the result, which is why starting early matters so much more than saving a little extra later.
Present value is the lump sum you start with — money already in the account on day one. Enter $0 if you are starting from scratch. Monthly contribution is what you add every month, such as an automatic transfer from your paycheck. Annual interest rate is the return your money earns each year, as a percentage. A savings account might pay 4% to 5%, while a diversified investment has historically averaged more — but with no guarantee. Years is how long the money stays invested. Compounding frequency is how often interest is added to your balance: monthly, quarterly, or annually. More frequent compounding gives a slightly higher result, because interest starts earning interest sooner.
The calculator works in compounding periods. With monthly compounding, the periodic rate is the annual rate divided by 12, and there are 12 periods per year. Your monthly contribution is spread evenly across each period, so with quarterly compounding each quarter receives three months of contributions. Contributions are assumed to be added at the end of each period.
The first part of the formula grows your starting lump sum; the second part grows all of your regular contributions. Your total contributions are the starting amount plus every monthly deposit. Interest earned is whatever is left — the future value minus everything you put in. In the worked example below, interest earned is actually larger than the total amount deposited, which is the normal pattern for a long savings horizon at a reasonable rate.
Two things are worth remembering. First, the result is in nominal dollars: it does not adjust for inflation, taxes, or fees, so the buying power of the final amount will be lower than the headline number. Second, the interest rate is an assumption, not a promise. A fixed-rate account like a certificate of deposit pays exactly what it says, but an investment can return more or less in any given year. Try a low rate and a high rate to see the range.
Worked example
Alex starts with $10,000 in a savings account, adds $200 every month, and earns 6% a year compounded monthly for 20 years. Here is how the future value works out, step by step.
Step 1: Find the periodic rate and the number of periods. The monthly rate is 6% ÷ 12 = 0.5% (0.005), and 20 years means 20 × 12 = 240 monthly periods.
Step 2: Grow the starting lump sum. $10,000 × (1.005)240 = $10,000 × 3.3102 = $33,102.04.
Step 3: Grow the monthly contributions. Each $200 deposit compounds for a different length of time, which the annuity part of the formula adds up: $200 × [((1.005)240 − 1) ÷ 0.005] = $200 × 462.04 = $92,408.18.
Step 4: Add the two parts. $33,102.04 + $92,408.18 = $125,510.22.
Step 5: Split the result. Alex put in $10,000 + ($200 × 240) = $58,000.00 in total, so the interest earned is $125,510.22 − $58,000.00 = $67,510.22 — more than the amount deposited.
Enter the same numbers — $10,000 starting amount, $200 a month, 6%, 20 years, monthly compounding — and the calculator shows exactly the same result: a future value of $125,510.22, made up of $58,000.00 deposited and $67,510.22 of interest.
FAQ
What is future value?
Future value is what a sum of money will be worth at a later date after it earns interest. A dollar today is worth more than a dollar in ten years, because money invested today earns interest and that interest earns interest of its own. The future value calculator works out that grown amount from your starting balance, your regular contributions, the interest rate, and the number of years.
How does compounding frequency change the result?
Compounding more often gives a slightly higher result, because interest is added to your balance sooner and starts earning interest itself. The difference between monthly and annual compounding is usually small — a few dollars on a small balance, more on a large one over many years. Monthly compounding is the most common choice for savings accounts and investments.
Are my monthly contributions added at the start or end of the month?
This calculator assumes contributions are added at the end of each compounding period, which is the usual setup for a regular monthly deposit. If you deposit at the very start of each period instead, the result would be slightly higher, because each deposit earns interest for one extra period.
Does future value include inflation?
No. The result is in nominal dollars — the actual dollar amount you would have. It does not adjust for inflation, taxes, or fees. If inflation averages 3% a year, $100,000 in twenty years would buy roughly what $55,000 buys today, so the real purchasing power is lower than the headline number.
What interest rate should I use?
Use the rate your money actually earns. A high-yield savings account might pay around 4% to 5%, a certificate of deposit has a fixed rate printed on it, and a diversified stock investment has historically averaged around 7% to 10% a year before inflation — but with no guarantee and plenty of ups and downs. Try a low rate and a high rate to see the range of possible outcomes.