The Price of Retiring in 2035, 2045, and 2055

Vanguard and J.P. Morgan publish a capital-market forecast every year, and most years the financial press treats the exercise as a formality, a rounding error between two firms that broadly agree stocks go up over time. This year they don't agree. Vanguard's 2026 outlook puts U.S. equity returns over the next five to ten years at 3.3% to 5.3% annually, weighed down by what the firm calls stretched valuations in large-cap technology. J.P. Morgan's own 2026 long-term assumptions, published the same season, put the number at 6.7%, holding roughly flat from the year before.

That is not a rounding error. Run both numbers through 29 years of compounding on a modest monthly contribution, and the gap between them is worth more than most people's entire down payment on a house. It is also a useful admission, from two firms with no incentive to hedge: nobody actually knows what the market will return over your specific working life. Honest retirement planning holds that uncertainty rather than papering over it with a single tidy assumption, which is the whole reason a real plan needs a range of inputs, not one number.

The formula nobody teaches

Start with the part of retirement income most people treat as a black box: Social Security. The benefit formula is public, stable, and almost nobody has actually seen it. It works in three tiers, called bend points, updated every year by the Social Security Administration. For a worker first eligible in 2026, the bend points sit at $1,226 and $7,391 of monthly average indexed earnings. Below the first bend point, Social Security replaces 90% of income. Between the two bend points, it replaces 32%. Above the second, only 15%.

The formula is progressive by design: a $50,000 earner gets a far higher percentage of income replaced than a $250,000 earner does, and it is capped by the payroll tax wage base, which rises to $184,500 in 2026. Earn above that and the extra income does nothing for your eventual benefit, because it was never taxed for Social Security in the first place. Claim before your full retirement age of 67 and the benefit is reduced on a fixed schedule, roughly five-ninths of one percent per month for the first three years early. Claim after 67, up to 70, and it grows by roughly two-thirds of one percent per month. The calculator above runs those exact mechanics, using your current income as a stand-in for a 35-year earnings history, a simplification worth knowing about but grounded in the real formula rather than a flat industry-average guess.

The 2032 problem

The formula only matters if the fund paying it stays solvent, and that is no longer a hypothetical decades away. The 2026 Social Security Trustees Report, released in June, moved up its projection for when the retirement trust fund's reserves run out: the fourth quarter of 2032, a full quarter earlier than the prior year's report. At that point, incoming payroll tax revenue alone would cover roughly 78% of scheduled benefits, which is where the widely cited "22% cut" figure comes from; the Congressional Budget Office, using its own economic assumptions, puts the automatic cut closer to 28%. If the retirement fund is combined with the smaller disability fund, the math is somewhat less dire: depletion in 2034, with 83% of benefits still payable.

Every one of Social Security's prior projected depletion dates has been met with a legislative fix before benefits were actually cut, most famously in 1983, when reserves were literally weeks from running dry. That track record is a real reason not to plan around the worst-case cut as a certainty. It is not, on its own, a reason to plan around no cut at all, which is why the calculator above forces a choice among three explicit scenarios rather than defaulting to an assumption that Congress will, once again, sort it out in time.

Where the real tax bite hides

A separate SwitchWize analysis checked a viral claim that 401(k) withdrawals get taxed at a flat 25% to 35%, and found the number overstated. Real effective rates for a typical retiree drawing a normal annual income run closer to 10% to 20%, because the standard deduction and the lower brackets absorb the first tranche of every year's withdrawal. The 2026 standard deduction is $16,100 for a single filer and $32,200 for a married couple filing jointly; the 22% bracket for a single filer doesn't start until taxable income clears $50,401.

But there is a real version of that warning, and it shows up specifically for people who over-concentrate savings in one traditional, pre-tax account. Required Minimum Distributions begin at age 73 (75 for anyone born after 1959), calculated by dividing the prior year-end balance by a fixed IRS life-expectancy factor, 26.5 at age 73. On a $2.8 million all-traditional balance, that forces a withdrawal of roughly $105,700 in the very first year, whether or not the money is needed that year. Stack that against Social Security, up to 85% of which becomes taxable once combined income clears a fairly low threshold, and a retiree who spent decades minimizing their tax bill can find themselves pushed into the 22% or 24% bracket in retirement, and past the 2026 threshold for Medicare's IRMAA surcharge (the Income-Related Monthly Adjustment Amount) of $109,000 (single) or $218,000 (joint), where Part B premiums jump from the standard $202.90 a month to as high as $689.90. That is the mechanism worth worrying about. It is a bracket-and-surcharge problem created by account concentration, not a flat tax rate on withdrawal, and it is exactly what the calculator's effective-tax-rate output above is modeling, using 2026's actual bracket structure inflated forward to your retirement year.

What nine years of runway costs that twenty-nine years doesn't

Hold the desired lifestyle constant, say $80,000 a year in today's purchasing power, Social Security included, and the size of the nest egg required to fund it, measured in today's dollars, barely changes with the year you retire. It sits in a fairly tight band regardless of whether that's 2035, 2045, or 2055, because both the target and Social Security's own value are being inflated by the same clock. What moves, by a factor of roughly four, is the monthly savings rate required to get there from zero, because compounding needs time and there is no substitute for it once the clock starts running out.

Illustrative: $80,000/year target, zero starting balance, 7% assumed return, a 10% Social Security cut scenario, and a Morningstar 2026 safe withdrawal rate of 3.3% to 3.9%.

That range is wide on purpose. It spans Morningstar's 2026 base-case safe withdrawal rate of 3.9% down to a more conservative 3.3%, the same gap that separates an optimistic and a cautious retirement planner today. Widen the return assumption from J.P. Morgan's 6.7% down to Vanguard's low end of 3.3%, and the required monthly figure for the 2055 cohort roughly doubles. None of these inputs are settled facts. They are the year's best published estimates from people whose job is estimating them, and they disagree with each other by enough to change the answer materially, which is the entire argument for running your own numbers on a range, adjusting them as the annual Trustees Report and capital-market outlooks update, rather than anchoring to a single figure found once and never revisited.

How to actually use this

Run the calculator at real numbers, then run it twice more: once at the conservative end of every slider, once at the optimistic end. If the required-monthly-savings figure at the conservative end is a number that's plausibly hittable, the plan is sound under stress. If only the optimistic case works, the plan is a bet on three separate forecasts, market returns, inflation, and Social Security reform, all breaking the same way at once. That's not a reason to panic. It's a reason to save more, retire later, diversify across account types so a tax-bracket surprise doesn't land all at once, or some combination of the three, made with the actual range in front of you instead of a single comforting average.

Methodology

Years to retirement is the entered retirement year minus the current year. Social Security is estimated from the 2026 bend-point formula (90%/32%/15% of average indexed monthly earnings, capped at the $184,500 wage base) applied to entered income, adjusted for claiming age relative to a full retirement age of 67, and inflated to the retirement year at the entered inflation rate. The nest egg needed is the inflated spending target minus the Social Security estimate, divided by the entered safe withdrawal rate. The projected balance compounds current savings and monthly contributions forward at the entered return assumption. The effective tax rate applies the real 2026 federal bracket structure and standard deduction, inflated forward to the retirement year by the same inflation rate, to 85% of the Social Security estimate plus the portfolio withdrawal. Historical S&P 500 figures are computed from actual annual total returns, 1990 through 2025.