Investment Calculator
Project how your investments grow: combine an initial lump sum with regular contributions earning compound returns. Compare scenarios, increase contributions over time, track milestones, and see inflation-adjusted results.
Estimate only: not professional advice. Results are mathematical projections based on the numbers you enter. They are not financial advice, and actual investment returns vary. Consider speaking with a qualified financial professional before making decisions.
The lump sum you start with today. Enter 0 for contributions-only growth.
Added at the end of each period. Enter a negative number to model withdrawals.
Raise your contribution each year (for example, 3 matches a typical annual raise). Set to 0 for flat contributions.
Set above 0 to also show the result in today's purchasing power.
Enter a second rate to compare two scenarios side by side (for example, 7 vs 5).
Your projection
Future value
$0
Total contributions
$0
Interest earned
$0
Estimate only: not professional advice. This projection assumes a constant rate and regular contributions; real markets fluctuate.
Year-by-year schedule
| Year | Balance | Contributed | Interest |
|---|
The math
FV = PV × (1 + r/n)^(n×t) + PMT × [((1 + r/n)^(n×t) − 1) / (r/n)]
PV = initial lump sum · PMT = contribution per period · r = annual rate (decimal) · n = compounding periods per year · t = years.
Contributions are assumed at the end of each period (ordinary annuity). If r = 0, FV = PV + PMT × total periods.
Inflation-adjusted value = FV ÷ (1 + inflation)^t.
PV = initial lump sum · PMT = contribution per period · r = annual rate (decimal) · n = compounding periods per year · t = years.
Contributions are assumed at the end of each period (ordinary annuity). If r = 0, FV = PV + PMT × total periods.
Inflation-adjusted value = FV ÷ (1 + inflation)^t.
Worked example: $500 per month for 30 years
Small changes in the assumed return compound into large differences over decades. Contributing $500.00 per month for 30 years with no initial investment:
| Annual return | Future value | Total contributed | Interest earned |
|---|---|---|---|
| 5% | $416,129.32 | $180,000.00 | $236,129.32 |
| 7% | $609,985.50 | $180,000.00 | $429,985.50 |
| 10% | $1,130,243.96 | $180,000.00 | $950,243.96 |
Moving from 5% to 10% nearly triples the outcome on identical contributions. This is why the scenario comparison above matters: always test a range of returns, not a single guess.
Why starting early beats investing more
Time does more work than money. At 7% compounded monthly, $200.00 per month:
| Start age (to 65) | Years | Total contributed | Future value |
|---|---|---|---|
| 25 | 40 | $96,000.00 | $524,962.68 |
| 35 | 30 | $72,000.00 | $243,994.20 |
| 45 | 20 | $48,000.00 | $104,185.33 |
Starting at 25 instead of 45 costs twice the contributions but produces five times the balance. Every year you wait, you lose the most powerful compounding years at the end.
Frequently asked questions
What is future value?
Future value (FV) is what a sum of money will be worth at a future date after earning compound interest. It answers questions like how much a lump sum or a series of regular contributions will grow to over a number of years at a given rate.
What is the future value formula?
For a lump sum: FV = PV x (1 + r/n)^(n x t). With regular contributions: FV = PV x (1 + r/n)^(n x t) + PMT x [((1 + r/n)^(n x t) - 1) / (r/n)], where PV is the initial amount, PMT the contribution per period, r the annual rate as a decimal, n the compounding periods per year, and t the years.
How do I calculate future value with monthly contributions?
Use the annuity part of the formula with n = 12. Example: contributing $500.00 per month for 30 years at 7% compounded monthly grows to $609,985.50: total contributions $180,000.00 and interest earned $429,985.50.
Example: $10,000 at 6% compounded monthly for 10 years?
$10,000.00 x (1 + 0.06/12)^120 = $18,193.97. The $10,000 grows by $8,193.97 in interest over the 10 years.
What happens if the interest rate is 0%?
With no growth, the future value is simply the initial amount plus every contribution: $5,000.00 + $200.00 x 60 months = $17,000.00.
Does monthly compounding beat annual compounding?
Yes, slightly. $10,000 at 6% for 10 years grows to $18,193.97 with monthly compounding versus $17,908.48 with annual compounding - a difference of $285.49.
What is inflation-adjusted future value?
It converts the nominal result into today's purchasing power: FV / (1 + inflation)^years. Example: $18,193.97 nominal becomes $14,213.10 in today's dollars after 10 years at 2.5% annual inflation.
Can this calculator model withdrawals too?
Yes. Enter a negative number in the contribution field to model regular withdrawals (for example, -300 for a $300 monthly withdrawal), and the projection will draw the balance down accordingly.
Are contributions assumed at the beginning or end of each period?
This calculator assumes contributions at the end of each period (an ordinary annuity), which is the standard for savings projections. Beginning-of-period contributions (annuity due) would earn one extra period of interest and give a slightly higher result.
How is 'interest earned' calculated?
Interest earned = future value minus everything you put in. Example: $2,500.00 initial plus $1,200.00 per year for 15 years at 8% gives a future value of $40,512.96; total contributions are $20,500.00, so interest earned is $20,012.96.
Is this calculator financial advice?
No. It produces mathematical estimates for educational purposes only, based on the constant rate and contributions you enter. Real investments fluctuate. It is not professional financial advice - consider consulting a qualified financial professional.
What is the difference between future value and present value?
They are opposites: future value asks what today's money becomes later, while present value asks what a future sum is worth today. Both use the same compound-interest math in reverse. You can explore compounding further with the Compound Interest Calculator on nrtechstudio.com.
How much will $10,000 grow to if I add $500 per month for 30 years?
At a 7% annual return compounded monthly, $10,000.00 initial plus $500.00 per month for 30 years grows to $691,150.47. You contribute $190,000.00 total, so compound growth adds $501,150.47 in interest.
What is a step-up contribution?
A step-up increases your contribution each year by a set percentage, for example 3% to match a typical annual raise. With a 3% yearly step-up on the example above, the future value rises from $691,150.47 to $914,744.96, a difference of $223,594.49, because larger later contributions still compound for many years.
Lump sum or monthly contributions: which grows more?
It depends on timing. Investing a $120,000.00 lump sum at 7% for 10 years gives $241,159.37, while contributing $1,000.00 per month for 10 years (same $120,000.00 total) gives $173,084.81. The lump sum wins because the full amount compounds from day one, but monthly contributions are more realistic for most savers.
When will I reach $1 million investing $1,000 per month?
At a 7% annual return compounded monthly with no initial investment, $1,000.00 per month crosses $1 million during year 28, reaching about $1,038,688.22. Use the milestone tracker above to see this for your own numbers.
Does starting early really matter?
Enormously. Investing $200.00 per month at 7% from age 25 to 65 (40 years) grows to $524,962.68, while starting at 35 (30 years) gives only $243,994.20. The 10 extra years cost just $24,000.00 in additional contributions but add $280,968.48 to the final balance.
What return rate should I assume for projections?
There is no guaranteed rate. Long-run US stock market returns average roughly 7% per year after inflation, but any single period can differ widely. Use the scenario comparison to test a conservative rate (for example, 5%) against an optimistic one (for example, 8%), and remember this tool is for education, not financial advice.
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