How is interest calculated on my contributions?

Each monthly contribution is added to the balance before the next month's return is applied, so every deposit compounds for as many months as remain until retirement. The formula used is the annuity future value: contribution x ((1 + monthly rate)^months - 1) / monthly rate. Contributions near the end earn very little interest; early ones earn the most.

Can I enter my employer match?

Yes — add your match to the monthly contribution. If you contribute $500 and your employer matches 50% ($250), enter $750 in the Monthly contribution field. Keep in mind the tool applies the same return to all contributions, so it does not model vesting schedules or match caps separately.

Why does the table show only some years?

To keep the display readable, the projection shows the starting row, every fifth year, and always the final year. The full year-by-year series, including all intermediate years, is included in the CSV export, so download it if you want the complete balance history for every single year.

What if my returns are negative?

The calculator will still run the projection and show the balance shrinking, because the return input accepts any number, including negative annual percentages. This can be a useful stress test, but remember it applies the same negative rate every month, which is pessimistic even for bear markets, so treat it as a worst-case illustration.

Does it include Social Security or pensions?

No. The projection covers only the savings and contributions you enter, so employer matches and future benefits must be added by hand. If you want the full picture, estimate your pension separately and compare its expected monthly payment with what your projected balance could sustainably withdraw.

Finance

Retirement Calculator

Project retirement savings growth with contributions and inflation.

retirementsavingsinvestmentpensionfuture

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About the Retirement Calculator

Retirement planning often stalls on one question: how much will I actually have? The Retirement Calculator answers it by projecting your savings forward year by year using monthly compounding, and it is built for people who want a clear, honest picture of their money at retirement rather than a rosy slogan. You enter your current age, target retirement age, current savings, monthly contribution, expected annual return, and an inflation assumption. The tool then computes the years to retirement, the future value of your existing lump sum, the future value of your ongoing contributions, the combined nominal balance, total contributions, and total interest earned. A separate inflation-adjusted figure discounts that future balance back into today's purchasing power, which is usually the number that matters most when you are deciding whether your savings rate is enough. A year-by-year table shown every five years plus the final year lets you watch compounding do its work, and a one-click CSV export preserves the full projection for your records or a meeting with your financial advisor.

Hand-written guide

Examples

Input

Age 30 to 65, $25,000 saved, $500/month, 7% return, 3% inflation

Output

35 years to retirement; $1,188,181 nominal; $422,260 inflation-adjusted; $953,181 total interest

Note: 35 years = 420 monthly periods at 7%/12 = 0.5833% per month. The lump sum compounds to about $287,700 and the $500 deposits accumulate to about $900,500, totalling $1,188,181. Contributions of $235,000 are subtracted, leaving $953,181 of interest; dividing by the 1.03^35 inflation factor (2.8139) gives $422,260 in today's dollars.

Input

Age 40 to 60, $100,000 saved, $1,000/month, 6% return, 2.5% inflation

Output

20 years to retirement; $793,061 nominal; $483,982 inflation-adjusted; $453,061 total interest

Note: 20 years = 240 months at 0.5% per month. The $100,000 compounds to about $331,000 and the $1,000 monthly deposits to about $462,000, totalling $793,061. Contributions total $340,000, so interest is $453,061; discounted by 1.025^20 = 1.6386, the real value is $483,982.

Input

Age 25 to 55, $0 saved, $300/month, 8% return, 3.5% inflation

Output

30 years to retirement; $447,108 nominal; $159,295 inflation-adjusted; $339,108 total interest

Note: 30 years = 360 months at 0.6667% per month; the $300 annuity grows to $447,108. Contributions total $108,000, so interest is $339,108; discounted by 1.035^30 = 2.8068, the real value is $159,295.

How to use

1
Enter your Current age and Retirement age in years — the Years to retire field fills itself automatically.
2
Fill in Current savings and Monthly contribution in US dollars.
3
Set Expected annual return and Inflation as annual percentages; 7 and 3 are the defaults.
4
Read the four headline stats: years to retirement, future value, inflation-adjusted value, and total interest earned.
5
Scroll the year-by-year projection table (every five years plus the final year) and use Export CSV to download it.

Common use cases

Checking whether a planned 401(k) contribution rate closes the gap to a target retirement balance.
Modelling the trade-off between retiring at 62 versus 67 before telling your employer.
Estimating the retirement value of a windfall lump sum such as a bonus or inheritance invested today.
Comparing a 6% conservative and an 8% optimistic return assumption side by side.
Setting an inflation-adjusted savings goal in today's dollars instead of misleading future dollars.
Preparing a year-by-year balance printout to review with a financial planner.

Best practices

Stress-test with several return assumptions — the difference between 5% and 8% over 30 years is enormous and the calculator makes it one keystroke to compare.
Pay most attention to the inflation-adjusted figure, since nominal balances overstate what your money will actually buy.
Keep inflation and returns as separate inputs; subtracting one from the other in your head gives a worse approximation than the tool's real-value math.
Remember contributions are assumed monthly and returns credited monthly — the projection is an estimate, not a guarantee.
Use the CSV export to keep a dated copy of your assumptions, so you can re-run the same scenario next year with fresh numbers.
Spot-check the first table row: year 1 should roughly equal savings plus 12 contributions plus about one year of interest.

Tips

Re-run the scenario three times with 5%, 7%, and 9% returns to see your plausible range.
Bump the inflation input to 4% for a conservative view of future purchasing power.
Export the CSV after each scenario and name it by assumptions so you can compare later.
Use the final-year age column to double-check that retirement age and projection end year line up.

Frequently asked questions

It is the projected balance divided by the cumulative inflation factor, expressed in today's purchasing power. A nominal $1.19 million in 35 years at 3% inflation buys what about $422,000 buys today. This figure keeps you from overestimating how wealthy you will be, because goods and services will cost more by then.

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