Quick start
- Open the Investment Calculator.
- Enter the starting money already invested.
- Enter the monthly amount you plan to add.
- Enter an estimated annual return and the number of years.
- Calculate, then read ending balance, total contributions, estimated growth, and the warning notes together.
Best uses
Start here if one of these sounds like your job. The examples below show which inputs matter most.
- Estimate future value from monthly investing.
- Compare how time and contribution size affect growth.
- Separate total contributions from estimated investment gains.
- Test return assumptions before using a real investment plan or adviser conversation.
What this calculator is for
The Investment Calculator estimates a future balance from starting money and monthly deposits. It is useful for comparing habits and assumptions, not choosing an investment.
Use it when you want to test a habit, like adding $250 a month, before deciding whether the goal needs more money, more time, or a lower-risk plan. It is projection math, not investment advice.
What to enter
Investment projections get misleading when a return guess is treated like a promise. Keep starting money, monthly deposits, estimated annual return, and years separate, then test a lower return before trusting the number.
- Enter the starting investment and monthly contribution.
- Enter an estimated annual return as a what-if percent.
- Enter the number of years you want to project.
Example walkthrough
Try the starter example: $5,000 plus $250 each month at 7% for 20 years. The estimate is about $150,425.36, with $65,000 from contributions and about $85,425.36 from the return assumption.
- $5,000 plus $250/month at 7% for 20 years is about $150,425.36.
- That example has $65,000 in contributions and about $85,425.36 in estimated growth.
Formula and steps
In plain language: The calculator compounds the starting amount and monthly contributions using an estimated annual return converted to monthly growth. For the starter example, $5,000 plus $250 each month at a 7% annual return for 20 years projects about $150,425.36. The calculator shows $65,000 of contributions and about $85,425.36 of estimated growth.
The calculator converts the annual return assumption into monthly growth, compounds the starting money, then adds each monthly contribution as an end-of-month deposit. Estimated growth equals ending balance minus the money you put in.
How to read the answer
Start with ending balance, then check total contributions and estimated growth. If growth is most of the answer, test a lower return so the plan is not balanced on one hopeful number.
- Ending balance is the projection, not a guarantee.
- Total contributions show the money you put in.
- Estimated growth is the difference between ending balance and contributions.
Common mistakes to avoid
Most bad investment projections come from using one high return, forgetting fees and taxes, skipping inflation, or acting like the market grows smoothly every year.
- Do not ignore investment fees and taxes.
- Do not ignore inflation when the goal is years away.
- Do not assume a steady return happens every year.
- Do not choose investments based only on a calculator projection.
What to try next
A related tool can help after the first investment projection. The next question is usually compounding detail, inflation pressure, or whether the same goal belongs in a retirement plan.
- Use Compound Interest Calculator for compounding frequency.
- Use Inflation Calculator to test buying-power pressure.
- Use Retirement Calculator if you have a target amount.
Sources and estimate notes
OpenStax explains time value of money, and Investor.gov is useful for the plain inputs behind this page: starting money, monthly contributions, time, fees, risk, return, and regular investing.
This calculator still stays simple. It does not include taxes, fees, inflation, withdrawals, changing returns, market losses, account limits, product risk, or advice about what you should buy.
Worked examples for Investment Calculator
About $150,425.36 ending balance, with $65,000 contributed and about $85,425.36 growth
About $24,540.94 ending balance, with about $14,540.94 growth
About $72,286.36 vs $176,471.69 ending balance
FAQ in plain language
When should I use the Investment Calculator?
Use it when you want to test the exact inputs on this page: Estimate future value from monthly investing. Compare how time and contribution size affect growth. The result is a check against your assumptions, not proof that a lender, tax app, broker, platform, or provider will use the same number.
What do the main Investment Calculator inputs mean?
Starting investment means the money already invested before the projection starts. Monthly contribution means the amount added at the end of each month in this simple model. Estimated return means the annual return assumption. It is not a promise and real markets move unevenly. Time means how many years the projection runs before showing the ending balance.
How does the Investment Calculator handle monthly deposits?
It converts the annual return assumption into monthly growth, compounds the starting money, then adds each monthly contribution at the end of the month. That timing is why the result is an estimate, not a brokerage statement.
Does this include withdrawals?
No. This version is for money going in, not money coming out. If you need retirement withdrawals, required minimum distributions, or a drawdown plan, use a dedicated retirement or payout calculator instead.
Does this include inflation?
No. It shows the future balance in the dollars you enter. Use the Inflation Calculator beside it if you want to see how buying power could shrink over the same years.
What is the Investment Calculator doing with my numbers?
In plain language: The calculator compounds the starting amount and monthly contributions using an estimated annual return converted to monthly growth. For the starter example, $5,000 plus $250 each month at a 7% annual return for 20 years projects about $150,425.36. The calculator shows $65,000 of contributions and about $85,425.36 of estimated growth.
How should I read the Investment Calculator answer?
Start with ending balance, then check total contributions and estimated growth. Contributions are the money you put in. Estimated growth is the part that came from the return assumption.
Related tools
- Compound Interest Calculator Estimate compound growth with deposits, rate, time, and compounding frequency.
- Retirement Calculator Project retirement savings from current balance, monthly contributions, and return.
- Inflation Calculator Estimate future cost and buying power from an annual inflation rate.
Keep exploring
If this guide is close but not exact, these links keep you near the same kind of problem.
- Finance Browse the full category for related tools that help with the same job.
- All free tools Search the complete Access Free Tools library by task, category, or tool name.
- All calculator and utility guides Find more plain-language examples, formulas, mistakes, and result explanations.
- Free calculator resources Start here when you are not sure which calculator page fits.
Privacy and copying results
Recent answers stay visible only while you work in the current browser tab. They are not sent to a server.
Use Copy answer when you want to save the inputs and result in notes, homework, a message, or a project list. Check the units, labels, and limits before copying.