Short answer
Savings last until the yearly gap uses them up.
The yearly gap is the useful starting point: what the household spends, plus taxes, minus reliable income. Savings last longer when the gap is smaller, starts later, or has more room to recover.
Start here
What you actually came to find out
Plain answers first. Sources stay below for checking details.
What is the main driver?
The yearly gap between spending and reliable income.
Why does Social Security matter?
It can reduce how much savings has to cover after benefits start.
Why do taxes matter?
Some withdrawals need to be larger than the spendable amount because tax comes out first.
Why does timing matter?
Earlier retirement creates more years before income and Medicare may begin.
Withdrawal gap
Spend minus income
The yearly draw starts with the spending gap after reliable income.
Source trail: Morningstar, SSA.gov
Social Security
Personal
SSA estimates depend on earnings history and claiming age.
Taxes
Gross needed
IRS distribution and tax rules can change how much must be withdrawn.
Source trail: IRS: Publication 590-B: Distributions from Individual Retirement Arrangements, IRS: Tax Inflation Adjustments
Spending
Household
BLS gives public spending context, but the plan uses the household amount.
Source trail: BLS
The answer is not one national age. It is the road created by income, spending, taxes, market returns, inflation, and time.
Neutral landscape
The shape of the question
Morningstar withdrawal research gives the retirement-income frame: savings duration depends on withdrawals, returns, inflation, asset mix, and time horizon.
Source trail: Morningstar
SSA estimates reduce or change the gap once benefits begin, and the amount depends on personal records and claiming age.
IRS distribution and tax rules matter because the account withdrawal can be larger than the household spending line.
Source trail: IRS: Publication 590-B: Distributions from Individual Retirement Arrangements, IRS: Tax Inflation Adjustments
BLS spending tables help benchmark the spending side, but personal living costs and dreams are the plan input.
Source trail: BLS
Curator core
What the authorities say
These sources are here for the reader who wants to check the work. The plain-English answer stays above them.
Source 01
Morningstar
The State of Retirement Income
Morningstar retirement income research studies starting withdrawal rates, asset mixes, and planning horizons.
Source framing
Morningstar frames withdrawal rates as assumptions that change with market returns, inflation, time horizon, and asset mix.
Strongest for: safe withdrawal rate research context
Read at MorningstarSource 02
Morningstar
What’s a Safe Retirement Withdrawal Rate for 2026?
Morningstar explains its 2026 safe starting withdrawal-rate research and the assumptions behind a 30-year retirement horizon.
Source framing
Morningstar treats retirement start date, spending flexibility, market assumptions, and nonportfolio income as linked withdrawal questions.
Strongest for: current withdrawal-rate context for retirement timing
Read at MorningstarSource 03
SSA.gov
Retirement Estimator
SSA explains how workers can estimate future benefits using their own earnings record.
Source framing
SSA points people to personal estimates because benefits depend on earnings history and claiming age.
Strongest for: personal Social Security estimates
Read at SSA.govSource 04
SSA.gov
When to Start Receiving Retirement Benefits
SSA explains early claiming, full retirement age, delayed retirement credits, and the claiming-age trade-off.
Source framing
SSA frames claiming age as a monthly benefit trade-off from age 62 through age 70.
Strongest for: official Social Security claiming-age rules
Read at SSA.govSource 05
IRS
Publication 590-B: Distributions from Individual Retirement Arrangements
Publication 590-B is the IRS source for IRA distributions, Roth ordering rules, and required minimum distributions.
Source framing
IRS Publication 590-B explains distribution rules that matter after money leaves an IRA.
Strongest for: RMDs, Roth distribution rules, and IRA withdrawals
Read at IRSSource 06
IRS
Tax Inflation Adjustments
The IRS annual inflation adjustment release is the primary source for federal brackets, standard deductions, and selected thresholds.
Source framing
IRS updates tax brackets, standard deductions, and many tax thresholds each year for inflation.
Strongest for: current federal tax-year thresholds
Read at IRSSource 07
BLS
Consumer Expenditure Surveys Tables
BLS Consumer Expenditure Survey tables show spending patterns by age and household type.
Source framing
BLS publishes spending tables that can be used as public benchmarks, not personal budgets.
Strongest for: retirement spending benchmarks
Read at BLSPlain-English forks
The forks people face
Most retirement questions hide a few smaller decisions. These are the practical pieces that change the plan.
How much is the monthly spending floor?
Why it matters: The spending floor is the amount that repeats before dreams and extras.
In real life: This fork sets the recurring draw.
What to look at: What to look at: core monthly spending.
When does income start?
Why it matters: Income start dates can create bridge years before the plan gets help.
In real life: This fork changes the early road.
What to look at: What to look at: Social Security, pension, work, and rental start ages.
Which accounts fund the gap?
Why it matters: Pre-tax, Roth, cash, and taxable money can have different tax treatment.
In real life: This fork changes the gross draw.
What to look at: What to look at: account type and withdrawal rules.
How long is the test?
Why it matters: A plan tested to 95 is different from a plan tested to 85.
In real life: This fork changes the finish line.
What to look at: What to look at: planning age and household life span assumptions.
Common questions
Quick answers
Short, plain answers for the questions people usually have next. The source trail stays available below.
What decides how long savings last?+
The main pieces are spending, reliable income, taxes, market returns, inflation, and the length of retirement.
Does Social Security make savings last longer?+
It can reduce the yearly gap after benefits start, but the amount depends on the personal record and claiming age.
Why do taxes affect savings duration?+
IRS rules can make the gross withdrawal larger than the spendable amount.
Does a 4 percent rule answer the whole question?+
No. Withdrawal research gives context, but a full plan also needs Social Security, taxes, spending, and time horizon.
Why can savings last longer in one version and shorter in another?+
A new retirement age, spending number, income start date, tax mix, or dream cost changes the gap.
What is depletion age?+
Depletion age is the age where savings run low or run out under the tested assumptions.
How this page is curated
This page uses withdrawal-rate research, SSA benefit-estimate guidance, IRS distribution and tax sources, and spending benchmarks to explain savings duration.
Read the planner methodologyTrust anchor
Sources used on this page
Every source named above is listed here in one place.
BLS. Consumer Expenditure Surveys Tables
https://www.bls.gov/cex/tables.htmIRS. Publication 590-B: Distributions from Individual Retirement Arrangements
https://www.irs.gov/publications/p590bIRS. Tax Inflation Adjustments
https://www.irs.gov/newsroom/irs-releases-tax-inflation-adjustments-for-tax-year-2026-including-amendments-from-the-one-big-beautiful-billMorningstar. The State of Retirement Income
https://www.morningstar.com/retirement/state-retirement-incomeMorningstar. What’s a Safe Retirement Withdrawal Rate for 2026?
https://www.morningstar.com/retirement/whats-safe-retirement-withdrawal-rate-2026SSA.gov. Retirement Estimator
https://www.ssa.gov/benefits/retirement/estimator.htmlSSA.gov. When to Start Receiving Retirement Benefits
https://www.ssa.gov/pubs/EN-05-10147.pdf
Before you act on this
This plan is educational. It is not personalized financial, tax, or insurance advice. Projections illustrate the math, they do not predict the future. Talk to your own licensed financial professional before acting on any of it.