Retirement Calculator

Will your savings last as long as you will? This calculator projects your nest egg to retirement, adjusts it for inflation, and compares it against the income you want — year by year through your expected retirement — so you can see whether you are on track, and by how much.

How It Works

Accumulation. Your current savings and monthly contributions are projected forward at your expected return, compounded monthly, to your retirement age. That gives a nominal (future-dollar) projection, which is then divided by the inflation factor over the same years to express it in today's dollars. Total contributions and investment growth are reported separately.

Need. The nest egg you need is calculated in today's dollars as the present value of an annuity due: your desired annual income, drawn at the start of each retirement year from retirement age to life expectancy, discounted at the real return — the inflation-adjusted rate $(1 + \text{nominal}) \div (1 + \text{inflation}) - 1$ . A nominal version of the target is also shown.

Verdicts and cross-checks. Your projected real savings minus the real nest egg needed is your surplus or shortfall, and the tool flags whether you are on track. Two extra lenses are provided: the monthly income your real nest egg supports at your chosen withdrawal rate, and the familiar 25× rule target — 25 times your desired annual income.

The Formulas

$\text{Projected (nominal)} = S\left(1 + \tfrac{r}{12}\right)^{12y} + C \times \frac{\left(1 + \tfrac{r}{12}\right)^{12y} - 1}{r/12}$

$\text{Nest Egg Needed (real)} = I \times \frac{1 - (1 + r_{real})^{-m}}{r_{real}} \times (1 + r_{real})$

where $S$ is current savings, $C$ the monthly contribution, $y$ the years to retirement, $I$ the desired annual income, and $m$ the years in retirement.

Input Parameters

| Parameter | Unit | Description | |---|---|---| | Current Age / Retirement Age | Years | Retirement age must exceed current age. | | Life Expectancy | Years | Must exceed retirement age; sets the drawdown horizon. | | Current Savings | Currency | What you have already accumulated. | | Monthly Contribution | Currency | Added every month until retirement. | | Expected Return | % per year | Nominal investment return before inflation. | | Inflation Rate | % per year | Used to convert results into today's dollars. | | Desired Annual Income | Currency | The yearly income you want in retirement, in today's dollars. | | Withdrawal Rate | % | Share of the nest egg drawn per year for the income cross-check (4% is the classic rule). |

Worked Example

You are 30, plan to retire at 65 and expect to live to 90. You have $50,000 saved, contribute$ 1,000 a month, assume a 7% return and 2.5% inflation, and want $60,000 a year in retirement at a 4% withdrawal rate.

Projected savings at 65: $2,376,362.19** nominal — **$ 1,001,330.27 in today's dollars. Of that, your contributions total $470,000; investment growth supplies$ 1,906,362.19.
Nest egg needed: ** $939,334.92** in today's dollars ($ 2,229,234.50 nominal), using the real return of 4.39% over 25 retirement years.
Surplus: $61,995.35 — you are on track, with a cushion of about 6.6% over the target.
Cross-checks: at a 4% withdrawal rate the projected real nest egg supports $3,337.77 a month**. The 25× rule target, however, is **$ 1,500,000 — well above your projection.

Interpreting the Results

Two targets, two philosophies. The annuity-based need ( $939,335 here) assumes you spend the nest egg down across exactly 25 years while it keeps earning the real return. The 25× target ($ 1,500,000) assumes you live off a 4% withdrawal indefinitely without consuming principal. Falling between them — as this example does — means you are funded for your stated life expectancy, but with little margin for living longer or leaving a legacy.
The real figures are the decision figures. Nominal balances flatter: $2.38 million sounds abundant until inflation restates it as$ 1.00 million of today's purchasing power.
Growth does the heavy lifting late. In the example, growth is four times contributions. Extending the horizon or starting earlier moves the result more than any realistic change in contribution.

Closing a Shortfall

The levers, in usual order of power: contribute more monthly (small increases compound for decades), retire later (more accumulation years, fewer drawdown years — a double effect), lower the target income, or assume a higher return only if your asset allocation genuinely supports it. Run the calculator after each change: the surplus figure tells you immediately whether the gap has closed.

Limitations

Constant return and inflation. Real markets deliver returns in an uneven sequence; a crash just before or after retirement hurts more than this smooth model admits.
No taxes, fees or other income. Account taxes, fund fees, Social Security, pensions and part-time work are excluded — treat desired income as the amount your portfolio alone must provide, or reduce it by the other income you expect.
Life expectancy is a point estimate. Planning to 90 and living to 100 is the classic longevity risk; a surplus today is partly insurance against it.

Frequently Asked Questions

Why is my 25× target so much higher than the nest egg needed?

They answer different questions. The calculator's need figure funds a fixed number of retirement years and allows the balance to be spent down. The 25× rule (the inverse of the 4% withdrawal rule) aims to preserve purchasing power indefinitely. If you want a legacy or a buffer for a longer life, aim nearer the 25× figure.

Should I enter my return before or after inflation?

Before. Enter the nominal return you expect and the inflation rate separately; the tool derives the real return itself. Entering an already-inflation-adjusted return while also entering inflation would double-count it.

Does this include Social Security or a pension?

No. If you expect $20,000 a year from other sources and want$ 80,000 in total, enter $60,000 as your desired income — the amount your savings must generate.