What annual return should I assume?

Broad, diversified stock portfolios have historically averaged roughly 7–10% per year before inflation over long periods, while bond-heavy mixes earn less. History is no guarantee of future returns, so many planners test a conservative 5–6% alongside an optimistic case. Run the calculator with a range of rates rather than a single number.

Does the calculator account for inflation?

No — the projection is in nominal (future) dollars. To think in today’s purchasing power, enter a real return instead: your expected return minus expected inflation, so 7% nominal with 3% inflation becomes roughly 4%. Our inflation calculator shows how far prices could move over the same period.

When are contributions applied — start or end of the month?

At the end of each month, after that month’s growth is credited (an ordinary annuity). A deposit therefore earns its first interest in the following month. Contributing at the start of each month would end slightly higher, but over long horizons the difference is small.

Does it include taxes, fees, or an employer match?

No. Fund expense ratios and advisory fees quietly compound against you, and taxes depend on whether the money sits in a 401(k), IRA, or taxable account. If your employer matches contributions, add the match to your monthly amount — it is part of what actually lands in the account.

How can I sanity-check the result?

Use the rule of 72: divide 72 by the annual return to estimate how many years money takes to double. At 7% that is about 10.3 years, so a dollar invested today can double roughly three times over a 30-year horizon. If the projected growth looks implausible, recheck the rate you entered.

No — the calculation runs entirely in your browser. Nothing you type is sent to a server or stored anywhere.

Retirement Calculator

Estimate your retirement savings by combining a starting balance with monthly contributions and growth.

Runs in your browser — files never leave your device

Current savings$Monthly contribution$Annual return%Years to retirement

Estimated nest egg

$772,315.45

Total contributed

$200,000

Growth

$572,315.45

How it works

This calculator projects what your retirement savings could grow to by combining four inputs: the balance you have today, a fixed monthly contribution, an assumed annual return, and the number of years until you retire. Growth compounds monthly, and every figure it reports is nominal — future dollars, with no adjustment for inflation, taxes, or fees.

The math converts your annual return to a monthly rate, r = annual rate ÷ 12, so 7% becomes about 0.5833% per month. Each month the balance is multiplied by (1 + r) and the contribution is then added, meaning deposits land at the end of the month — an ordinary annuity, where each deposit earns its first interest the following month. Over n months this is equivalent to the closed formula FV = P × (1 + r)^n + M × ((1 + r)^n − 1) ÷ r, where P is your current balance and M the monthly contribution.

Worked example using the tool’s defaults: $20,000 saved today, $500 added monthly, a 7% annual return, and 30 years (n = 360 months). The projected nest egg is $772,315.45. You contributed $200,000 of it — the $20,000 starting balance plus 360 × $500 = $180,000 in deposits — while growth accounts for the remaining $572,315.45. Nearly three-quarters of the ending balance comes from compounding, not from money you put in.

That split is why compounding is heavily back-loaded. By the rule of 72, money earning 7% doubles roughly every 72 ÷ 7 ≈ 10.3 years, so a dollar invested in year one can double about three times before a 30-year retirement date, while a dollar invested in the final decade doubles once at best. Starting earlier usually moves the outcome more than contributing harder later.

Treat the output as a scenario, not a promise. Real markets do not deliver the same return every year — outcomes depend on the sequence of good and bad years, and no return is guaranteed. The figure is also nominal: at 3% inflation, money 30 years out buys far less than the same amount today. A common fix is to enter a real return (your nominal assumption minus expected inflation) so the result reads in today’s purchasing power. Taxes, fund fees, and employer matches are not modeled.

Frequently asked questions

What annual return should I assume?: Broad, diversified stock portfolios have historically averaged roughly 7–10% per year before inflation over long periods, while bond-heavy mixes earn less. History is no guarantee of future returns, so many planners test a conservative 5–6% alongside an optimistic case. Run the calculator with a range of rates rather than a single number.
Does the calculator account for inflation?: No — the projection is in nominal (future) dollars. To think in today’s purchasing power, enter a real return instead: your expected return minus expected inflation, so 7% nominal with 3% inflation becomes roughly 4%. Our inflation calculator shows how far prices could move over the same period.
When are contributions applied — start or end of the month?: At the end of each month, after that month’s growth is credited (an ordinary annuity). A deposit therefore earns its first interest in the following month. Contributing at the start of each month would end slightly higher, but over long horizons the difference is small.
Does it include taxes, fees, or an employer match?: No. Fund expense ratios and advisory fees quietly compound against you, and taxes depend on whether the money sits in a 401(k), IRA, or taxable account. If your employer matches contributions, add the match to your monthly amount — it is part of what actually lands in the account.
How can I sanity-check the result?: Use the rule of 72: divide 72 by the annual return to estimate how many years money takes to double. At 7% that is about 10.3 years, so a dollar invested today can double roughly three times over a 30-year horizon. If the projected growth looks implausible, recheck the rate you entered.
Is my data uploaded?: No — the calculation runs entirely in your browser. Nothing you type is sent to a server or stored anywhere.

Retirement Calculator

How it works

Frequently asked questions

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