How does the future value formula work?

We compound monthly. Future value = P × (1+r)^n + PMT × (((1+r)^n − 1) / r), where r is the monthly rate (annual ÷ 12) and n is total months. Contributions are added monthly and the initial amount grows alongside them.

No. The annual return you enter is an assumption. Real returns vary, and past performance never guarantees future results. This is a planning tool, not financial or investment advice.

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Investment Calculator

Project the future value of your investments with monthly compounding.

Initial amount

Monthly contribution

Annual return (%)

Years

What is an investment calculator?

An investment calculator projects how much your money can grow over time, combining a starting amount with regular contributions and compounded returns. You enter how much you begin with, how much you add each month, the annual return you expect, and how many years you plan to invest. The tool then simulates monthly compounding on both the initial sum and each new contribution to estimate the future value of the portfolio, along with the total you put in and the growth earned on top of it. Monthly compounding is powerful because every month the returns you earn begin earning their own returns, so growth accelerates the longer you stay invested. People use an investment calculator to set saving goals, plan for retirement, compare a lump sum versus regular contributions, and see how much of the final result comes from their own money rather than from investment growth. The returns you assume are estimates, not guarantees, so treat the result as a planning target rather than a promise.

Example

Enter an initial amount of $1,000, a monthly contribution of $100, an annual return of 8% and 20 years. The tool estimates a future value of about $63,829, with $25,000 total invested and $38,829 of growth from compounding.

Who is this investment calculator for?

An investment calculator projects how a starting amount plus regular monthly contributions grows with compounding. It answers the "investment calculator" question for the people who search it most:

Students and young adults: an investment calculator for students and young adults starting small, seeing how a monthly contribution and compounding reward consistency.
Couples: an investment calculator for couples planning a shared goal, comparing how one extra monthly contribution changes the future value over decades.
Salaried professionals: an investment calculator for salaried professionals building a long-term portfolio, testing the split between the money invested and the growth it earns.
Retirees: an investment calculator for retirees checking whether a lump sum plus regular contributions reaches a retirement target by the time it is needed.

Investment growth table

This table shows how a $1,000 initial amount with a $100 monthly contribution grows at an 8% annual return, recomputed with the tool's own formula — FV = P × (1+r)^n + PMT × (((1+r)^n − 1) / r). Use it as an investment chart to see how time, not just the amount invested, builds most of the value.

Years	Future value	Total invested	Growth
5	$8,838	$7,000	$1,838
10	$20,514	$13,000	$7,514
15	$37,911	$19,000	$18,911
20	$63,829	$25,000	$38,829

Common use cases

Setting a savings goal and checking whether your monthly amount reaches it on time.
Comparing the effect of an extra monthly contribution over a long horizon.
Planning for a large expense such as a down payment or education fund.
Understanding the split between the money you deposit and the growth it earns.

Pro tips

Small regular contributions beat occasional big deposits over long periods because they compound for longer.
Use a conservative return you are comfortable with — historical equity averages are not a guarantee.
For an inflation-adjusted view, subtract your expected inflation from the return.
The length of time matters more than the return; sticking with a plan for decades creates most of the value.

How to use this investment calculator

Enter your starting or initial amount.
Enter the amount you plan to add each month.
Enter an assumed annual return percentage.
Enter how many years you plan to invest, then click Calculate future value.

How future value is calculated

FV = P × (1+r)^n + PMT × (((1+r)^n − 1) / r)
r = annual return ÷ 12, n = years × 12

Monthly compounding is applied to both your initial amount and each contribution. Total invested is the sum of all money you put in; growth is the compound interest on top.

FAQ

What growth rate should I assume?

Common planning assumptions range around 6–10% for long-term diversified portfolios, but you should pick a rate you are comfortable with. We are not providing financial advice.

Does this account for inflation?

No. Future value is in today's purchasing terms. For a real (inflation-adjusted) view, use a lower return that subtracts your expected inflation.

Is it private?

Yes — it runs entirely in your browser.

What annual return should I assume?

Common long-term planning numbers range around 6-10% for diversified portfolios, but you should use a rate you are comfortable with. It is an assumption, not a promise.

What is monthly compounding?

Interest is calculated and added to the balance every month, so future returns earn returns on themselves. This is what makes growth accelerate over time.

What does total invested mean?

The sum of your initial amount plus every monthly contribution you make — the cash you actually put in.

How does the calculator handle contributions?

Each monthly contribution is added to the balance and then compounds, so contributions made early in the period grow for longer.

Does this account for inflation or taxes?

No. The future value is expressed in today’s purchasing terms and ignores fees and taxes.

Is this financial advice?

No. This is a planning tool for estimates only. Consult a qualified financial adviser before making decisions.