Investment Calculator
Estimate how a lump sum and regular monthly investing could grow, with a year-by-year table.
Results
| Item | Value |
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Year by year
| Year | Total put in | Balance |
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Quick Answer
An investment grows from its starting amount and regular additions. If you start with $10,000 and add $500 a month at a 7% yearly return, compounded monthly, you could have about $300,851 after 20 years. Of that, $130,000 is money you put in.
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Table of Contents
How This Investment Calculator Works
This calculator estimates how money grows when returns are added and then earn returns themselves. It is built for regular investing, so you can see the effect of monthly contributions over time.
Quick explanation: balance = growth on your starting amount + growth on your monthly contributions.
- Return: a steady yearly rate. Real returns change each year.
- Contributions: added at the end of each month.
- Table: shows your balance after each year.
Core Formulas
- Monthly rate: r = yearly return ÷ 12
- Future value: FV = P × (1 + r) ^ n + M × ((1 + r) ^ n − 1) ÷ r
- With a 0% return: FV = P + M × n
P is the starting amount, M is the monthly contribution, and n is the number of months.
Worked Example
You invest $300 a month for 10 years at a 5% yearly return, with no starting amount.
- Number of months = 120
- Total put in = $36,000
- Estimated balance = $46,584.68
What Can Change Your Result
- Market returns: values can fall as well as rise.
- Fees: even small yearly fees can reduce growth over time.
- Taxes: these depend on your account type and location.
- Inflation: a future balance buys less than the same amount today.
Frequently Asked Questions
Grow your starting amount by the return each period, then add the growth on each contribution. This calculator does both.
At a 7% yearly return for 20 years, with $10,000 to start, it could reach about $300,851. Results change with your return.
Use a rate you consider realistic, and test a few rates. Returns are never guaranteed.
This one focuses on regular monthly investing, with a yearly table of what you put in and what you have.
No. Both will lower your real result.
References & Sources
| Source | Used For | Link |
|---|---|---|
| U.S. SEC, Investor.gov compound interest calculator | How compounding grows savings. | https://www.investor.gov/financial-tools-calculators/calculators/compound-interest-calculator |
| Wikipedia, Future value | Future value formulas. | https://en.wikipedia.org/wiki/Future_value |