Investment Calculator
See what a starting amount plus monthly deposits grows to at a fixed annual return, compounded monthly, with the balance, gain and deposits for every year. How it works
Use the Investment Calculator
About the Investment Calculator
$500 a month for 30 years at 7% grows to $609,985.50, of which $180,000.00 is your own deposits. The investment calculator compounds a nominal annual return monthly on a starting amount plus monthly deposits, made at the end or the start of each month, and charts and lists the balance year by year. Enter an inflation rate to see the end balance in today’s money as well.
What a monthly deposit grows to at 5%, 7% and 9%
| Monthly deposit and return | 10 years | 20 years | 30 years |
|---|---|---|---|
| $100 a month at 5% | $15,528.23 | $41,103.37 | $83,225.86 |
| $300 a month at 5% | $46,584.68 | $123,310.10 | $249,677.59 |
| $500 a month at 5% | $77,641.14 | $205,516.83 | $416,129.32 |
| $100 a month at 7% | $17,308.48 | $52,092.67 | $121,997.10 |
| $300 a month at 7% | $51,925.44 | $156,278.00 | $365,991.30 |
| $500 a month at 7% | $86,542.40 | $260,463.33 | $609,985.50 |
| $100 a month at 9% | $19,351.43 | $66,788.69 | $183,074.35 |
| $300 a month at 9% | $58,054.28 | $200,366.06 | $549,223.04 |
| $500 a month at 9% | $96,757.14 | $333,943.43 | $915,371.74 |
No starting amount and deposits at the end of each month. The rate is nominal and compounded monthly: one twelfth of it is added to the balance each month. Deposits per $100 a month total $12,000.00, $24,000.00 and $36,000.00. Fixed rates for illustration, not a forecast.
Deposits at the end or the start of the month
| Years | Total contributed | End of month | Start of month | Difference |
|---|---|---|---|---|
| 10 years | $70,000.00 | $100,133.64 | $100,543.34 | $409.70 |
| 20 years | $130,000.00 | $264,122.49 | $265,277.59 | $1,155.10 |
| 30 years | $190,000.00 | $562,483.27 | $564,994.56 | $2,511.29 |
$10,000 to start plus $500 a month at 6% a year. A deposit made at the start of a month earns one more month of interest.
Frequently asked questions
- How much will $500 a month be worth in 30 years?
- At 7% a year, $609,985.50: $180,000.00 of deposits and $429,985.50 of gain. At 5% it is $416,129.32 and at 9% $915,371.74. These figures use end-of-month deposits and monthly compounding.
- How much will $10,000 be worth in 10 years?
- With no further deposits and a 7% return, $20,096.61 after 10 years and $81,164.97 after 30. With $500 a month added at 6%, the 10-year figure is $100,133.64. Enter an annual inflation rate to see the end balance in today’s money as well, the balance divided by (1 + inflation)^years: at 3% inflation that $100,133.64 is worth $74,508.83 today.
- Is the return compounded monthly or yearly?
- Monthly. The annual rate you enter is a nominal rate and one twelfth of it is applied to the balance each month, so 7% entered works out to about 7.23% over a full year. For yearly, quarterly or daily compounding use the compound interest calculator, which returns the same $609,985.50 for $500 a month at 7% over 30 years when it is set to monthly.
- What rate should I enter for a fund’s average annual return?
- A fund’s average annual return is usually a yearly figure, so entering it here overstates the result slightly. The monthly rate that matches 7% a year is 6.78% entered: $500 a month for 30 years then ends at $584,156.39 instead of $609,985.50.
- Does it matter if I deposit at the start or the end of the month?
- Slightly. $10,000 plus $500 a month at 6% reaches $100,133.64 in 10 years with end-of-month deposits and $100,543.34 with start-of-month deposits, $409.70 more. Over 30 years the gap is $2,511.29.
- Can I enter a negative return?
- Yes. At -5% a year, $10,000 plus $500 a month for 10 years ends at $53,351.28. That is $16,648.72 less than the $70,000.00 put in, and the total gain shows as -$16,648.72.
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