Retirement projection
Year 0 starts with current savings. The chart shows accumulation to retirement, then projected drawdown through retirement.
Age-by-age projection
The schedule shows the key ages from today through retirement drawdown.
| Age | Balance | Contributions | Retirement withdrawals |
|---|
How this retirement calculator works
This calculator has two distinct phases, and that matters for interpretation. Before retirement, it compounds the current savings balance monthly and adds monthly contributions that can grow each year. At retirement, it converts your desired retirement income into a required portfolio need after subtracting other retirement income, then compares that required pot with the projected pot you have built.
Under the default scenario, the model assumes age 34 today, retirement at age 66, and 29 years of retirement. Starting with $24,000.00 and contributing $1,000.00 per month, with annual contributions rising by 2%, the tool projects a retirement pot of about $1,722,210.94.
The same default assumptions imply a required pot of about $1,649,247.78 to support the modeled retirement-income gap. That leaves a projected surplus of $72,963.16 in this deterministic scenario. The long-form content below is the technical manual for understanding where those numbers come from and when they should not be trusted at face value.
Core formulas and variable definitions
The pre-retirement accumulation phase converts the annual pre-retirement return assumption into a monthly rate and compounds month by month.
Formula: Monthly pre-retirement rate (i) = (1 + Annual pre-retirement return (r_pre))^(1 / 12) - 1
Formula: Balance at month t (B_t) = Balance at month t-1 (B_t-1) x (1 + i) + Monthly contribution at month t (C_t)
- Monthly pre-retirement rate (i) = effective monthly investment growth rate before retirement.
- Annual pre-retirement return (r_pre) = user-entered annual return assumption before retirement.
- Monthly contribution at month t (C_t) = monthly savings amount, which can increase each year.
With the default assumptions, the pre-retirement annual return of 6.5% converts to an effective monthly rate of about 0.5262%.
The retirement-income target is built from current income and replacement percentage first, then inflated forward to retirement:
Formula: Desired income today (Y_0) = Current income (I_0) x Income replacement ratio (q)
Formula: Desired income at retirement (Y_R) = Y_0 x (1 + Inflation rate (pi))^(Years to retirement)
Formula: Other income at retirement (O_R) = Other income today (O_0) x (1 + pi)^(Years to retirement)
Formula: First-year portfolio withdrawal (W_1) = max(0, Y_R - O_R)
- Desired income today (Y_0) = retirement spending target expressed in today's money.
- Income replacement ratio (q) = percentage of current income you want to replace in retirement.
- First-year portfolio withdrawal (W_1) = amount the investment portfolio must fund in year one of retirement after other income is deducted.
The required pot at retirement is then valued as a growing drawdown stream:
Formula: Required pot (P_R) = W_1 x [1 - ((1 + pi) / (1 + r_post))^N] / [1 - ((1 + pi) / (1 + r_post))]
- Required pot (P_R) = estimated retirement portfolio needed at retirement date.
- Annual post-retirement return (r_post) = expected annual portfolio return during drawdown.
- Inflation rate (pi) = annual inflation assumption used to escalate withdrawals.
- Retirement years (N) = modeled number of years the portfolio must support withdrawals.
Default scenario breakdown
The default case uses current income of $65,000.00 and an income replacement target of 68%. That produces a desired retirement-income target of about $44,200.00 in today's money.
After inflating that spending target forward by 2.8% over 32 years, the tool estimates a first-year retirement-income need of roughly $106,955.21. Other retirement income of $14,000.00 today is also inflated forward, reaching about $33,877.22 by retirement age. The difference leaves a year-one portfolio withdrawal need of about $73,077.99.
That withdrawal stream is what drives the required pot estimate. The projected pot comes from the accumulation engine; the required pot comes from the drawdown engine. They answer different questions, and a good retirement page needs to explain both.
Choosing a retirement income target
A replacement percentage is a fast planning shortcut, not a universal rule. Many households do need less gross income after retirement because payroll taxes, commute costs, mortgage payments, or retirement-plan contributions may fall. Other households need more because healthcare, housing, dependants, long-distance family support, or travel remain expensive.
The real information gain comes from separating spending tiers. Instead of one replacement number, many planners should test at least three levels: essential spending, comfortable baseline spending, and aspirational spending. That exposes whether the retirement gap is driven by true minimum living cost or by an optional lifestyle layer.
It also matters that “other retirement income” is entered in today's money. This keeps the replacement-rate logic consistent with the rest of the model. If that other income is overstated or understated, the required pot can move materially.
What changes the retirement outcome most
Three levers dominate most retirement outcomes: retirement age, savings rate, and spending target. A later retirement age helps twice. It gives the portfolio more time to grow and it shortens the number of years the portfolio must fund. That double effect is why even a modest delay can often move the result more than a slightly higher return assumption.
Savings rate is the lever most households control directly. In the default scenario, the tool estimates that about $952.69 per month would close the gap exactly under the model. That is slightly below the current default contribution, which is why the result shows a surplus rather than a shortfall.
Return assumptions matter too, but they are the least controllable lever. Raising expected returns is mathematically easy and behaviorally dangerous. A page like this should therefore emphasize contribution margin and retirement timing before it encourages more optimistic market assumptions.
Hidden variables most retirement calculators ignore
The largest hidden variable is sequence-of-returns risk. A deterministic average return hides the damage that poor returns can do near retirement or early in drawdown. Two portfolios with the same long-run average return can produce very different retirement outcomes if one experiences losses in the years when the balance is largest and withdrawals have started.
The second hidden variable is fee drag. The SEC has repeatedly warned that even modest recurring fees can materially reduce long-run portfolio value. Over multi-decade retirement planning horizons, fee drag compounds because every year's cost reduces the base that future returns are earned on.
The third hidden variable is policy and benefit uncertainty. Social Security and state pension systems are real retirement-income pillars, but the timing, taxation, and claiming decisions can matter. SSA guidance makes clear that retirement benefits can start as early as age 62, but benefit amounts vary with claiming age and earnings history. That means “other retirement income” should be treated as a planning estimate, not a guaranteed constant unless the benefit is already contractually defined.
The fourth hidden variable is healthcare and long-term care cost. Generic retirement tools often mention it vaguely and then ignore it numerically. That omission matters because retirement spending shocks are not evenly distributed across years, and late-life care costs can overwhelm a smooth percentage-based spending model.
Inflation and drawdown realism
The BLS treats inflation as a broad rise in prices across the economy, and that is exactly why retirement drawdown modeling cannot ignore it. A retiree does not usually spend a flat nominal amount forever. Food, housing, healthcare, utilities, and services all reprice over time, which means a static nominal withdrawal target can understate the real portfolio need.
This page inflates withdrawals after retirement rather than leaving them flat. That is directionally correct for planning, but it still remains simplified. Real retiree spending is often uneven. Some categories fall early, healthcare may rise later, housing may behave differently from headline CPI, and large one-off costs may matter more than smooth annual inflation.
That is why this calculator should be read as a structured baseline model. It is much better than a flat-pot target, but it is still not a substitute for a full cash-flow retirement plan with taxes, healthcare, and account sequencing.
How to use the chart and age-by-age schedule
The chart shows the accumulation phase up to retirement age and the drawdown phase afterward. The horizontal required-pot line indicates the estimated amount needed at retirement date, not a moving line through retirement. That distinction matters: the required pot is an entry condition for drawdown, while the subsequent balance path shows whether the projected pot erodes under the modeled withdrawals and post-retirement return.
The age-by-age schedule is the audit trail behind the headline result. It shows how much of the outcome is explained by contributions before retirement and how large withdrawals become after retirement begins. If a retirement plan looks strong only because early drawdown remains high while the late-life balance collapses, the table will show that more clearly than the KPI cards alone.
This is also where users can see whether contribution growth is doing real work. In many cases, a modest annual increase in contributions is one of the most defensible ways to strengthen the plan without depending on higher return assumptions.
Assumptions and limitations
This is a deterministic planning model, not financial advice. It does not simulate market volatility, taxes, fees, contribution limits, sequence-of-returns risk, changing income, pension rules, healthcare shocks, or one-off spending.
It assumes monthly compounding before retirement, annual inflation-linked withdrawals during retirement, stable pre- and post-retirement return assumptions, and a smooth contribution-growth path. Those are reasonable for structured comparison, but they are not how actual retirement journeys unfold year by year.
Use it for first-pass planning, then validate the outcome with account-specific fee assumptions, tax treatment, and a more detailed retirement-income plan. For related work, the investment calculator for flexible contribution and solve-mode scenarios, the millionaire calculator for milestone-based wealth targets, the savings calculator for simpler accumulation cases, and the mortgage calculator for debt-carrying cost analysis are the strongest sibling tools in this cluster.
Frequently asked questions
What does the default retirement calculator scenario show?
On the current default inputs, the calculator projects a retirement pot of about $1,722,210.94 by age 66, versus an estimated required pot of $1,649,247.78. That leaves a projected surplus of $72,963.16 under this deterministic model.
What is the difference between projected pot and required pot?
Projected pot is the amount your savings plan may accumulate by retirement under the pre-retirement growth and contribution assumptions. Required pot is the estimated amount needed at retirement to fund the inflation-adjusted income gap after other retirement income has been deducted.
Why does the calculator ask for returns before and after retirement separately?
Many plans use a higher expected return while accumulating and a lower return during drawdown because portfolio risk often changes in retirement. This tool reflects that by separating pre-retirement and post-retirement assumptions instead of pretending one rate applies equally to both phases.
How is the retirement income target estimated?
The page starts with your current income and applies the replacement-rate percentage to estimate desired income in today's money. It then inflates that amount forward to retirement age and subtracts other retirement income, such as Social Security, State Pension, pension income, or annuity income, to estimate the year-one withdrawal the portfolio needs to support.
Should I include Social Security or pension income here?
Yes, if you want the portfolio need to reflect income already expected from outside the investment pot. The tool treats that amount as annual income in today's money and inflates it forward to retirement, which is usually more realistic than ignoring it completely.
Does this retirement calculator include taxes, fees, or healthcare shocks?
No. It does not model tax brackets, pension taxation, fund fees, advisory fees, healthcare shocks, long-term care, required minimum distributions, or one-off spending events. Those can materially change the outcome and should be layered on afterward.
What is the biggest hidden risk in a deterministic retirement model?
Sequence-of-returns risk is one of the biggest missing variables. A smooth average return is mathematically convenient, but poor returns near retirement or early in drawdown can damage plan durability even if the long-run average return looks acceptable.
How should I use this page in real retirement planning?
Use it as a first-pass planning manual, then run conservative, base, and optimistic scenarios. If the gap changes sharply when return, retirement age, or contribution assumptions move slightly, the plan likely needs a higher contribution margin, lower spending target, or later retirement date.