Retirement Planning Calculators

The version of retirement planning that gets written for the mass market (save 15% of your income, max your 401(k) match, follow the 4% rule) works as a starting point but breaks down quickly for anyone earning above the median. Once you're in the 32% or 35% bracket, contribution-limit math matters more than savings-rate math: the $23,500 employee 401(k) limit, the $7,000 IRA limit, and the $4,400 HSA limit are all hard ceilings that high earners hit before they've saved anything close to 15% of gross income. The choice between Traditional and Roth becomes a five-variable optimization (current bracket, retirement bracket, time horizon, NIIT exposure, IRMAA tier). Sequence-of-returns risk in the first 5 to 10 years of retirement matters more than the 30-year average return. And the Social Security claiming choice (defer to 70 versus take at 62) is worth six figures over a normal lifespan, but the right answer depends on health, spouse benefit interaction, and tax-bracket smoothing. The calculators below run the actual math: 401(k) projection with employer match and Section 415 limits, retirement accumulation plus drawdown with inflation-adjusted spending, Roth IRA with 2026 MAGI phaseouts, and the apples-to-apples Roth vs Traditional comparison that handles the tax-savings-reinvested case properly.

The 4% rule and why it's not actually a rule

Bill Bengen published the original 4% finding in 1994 using historical U.S. data from 1926 to 1976, testing the maximum sustainable withdrawal rate from a 60/40 portfolio across rolling 30-year windows. The worst-case starting cohort (a retiree entering the 1966 stagflation) could have safely withdrawn 4.15% of starting balance, inflation-adjusted annually, without depleting the portfolio over 30 years. The rule got rounded down to 4% in the press, and the methodology got mostly lost along the way: backward-looking, U.S.-only, 30-year horizon, 60/40 allocation, mechanical inflation adjustment. Subsequent research (Wade Pfau, Michael Kitces, the Bogleheads forum's actuarial work) has revised the safe withdrawal rate downward in current conditions to 3.0-3.5% for someone retiring today, citing lower expected real returns from bonds, higher U.S. equity valuations, and longer life expectancies. The 4% framing is still a useful upper bound, but treating it as a contract rather than a probabilistic guideline is the mistake. A 30-year-old planning a 40-year retirement window needs a different number than the original study addresses, and anyone retiring at 55 should plan for a 35-40 year horizon, which historically supports a lower withdrawal rate. The retirement calculator uses inflation-adjusted withdrawals and lets you stress-test against lower assumed returns.

Tax bucket strategy: which account holds what

Most retirement portfolios end up in three tax buckets: tax-deferred (Traditional 401(k), Traditional IRA), tax-free (Roth 401(k), Roth IRA), and taxable (brokerage). Each has different rules on contributions, withdrawals, and how investment returns get taxed. The harder question is what asset class to hold inside each bucket, not just which bucket to fund. Bonds and high-turnover funds generate ordinary income and short-term gains, so they're best held inside the tax-deferred or tax-free buckets where annual taxation doesn't drag returns. International stocks generate foreign tax credit eligible dividends that work best in taxable accounts where you can claim the credit. U.S. stock index funds are tax-efficient (low turnover, qualified dividends taxed at LTCG rates) and work in any bucket, but they shine in Roth where decades of compounding produce tax-free withdrawals. Real estate investment trusts (REITs) pay non-qualified dividends taxed as ordinary income, so they belong inside tax-deferred or Roth, not taxable. The order of contributions matters too: max the 401(k) match first (free money), then HSA if eligible (triple tax advantage), then maxing the 401(k) employee limit, then Roth IRA if income permits backdoor Roth otherwise.

Sequence-of-returns risk: why the first 10 years matter most

Average return over a 30-year retirement isn't the relevant statistic. What matters is the sequence of returns, particularly what the market does in the first 5 to 10 years of withdrawals. Two retirees with identical 30-year average returns can have radically different outcomes: one whose first decade was rough (think 2000-2009) may run out of money by year 22, while the other (good first decade, rough end) sails through with the portfolio intact. Every dollar withdrawn during a market drawdown locks in a permanent loss, because that dollar wasn't there to participate in the recovery. Two strategies help. First, hold 1-3 years of expected spending in cash and short-duration bonds at retirement, and spend from there during equity drawdowns rather than selling stocks at the bottom. Second, build flexibility into the spending plan: in years following a 20%+ market decline, trim discretionary spending by 10-20% to preserve principal. Both move the historical safe withdrawal rate up about 0.5 percentage points. The retirement calculator on this site models sequence-of-returns risk by running real historical paths rather than averaging assumed returns.

When to take Social Security

Full retirement age (FRA) for anyone born in 1960 or later is 67. Claiming at 62, the earliest available, cuts the benefit by 30% permanently. Deferring to 70 increases it by 8% per year above FRA, so a 70-year-old claimant gets 124% of their FRA benefit. The breakeven math: claiming at 70 produces a higher monthly benefit, but you give up 8 years of payments to get it. On a $3,000/month FRA benefit, claiming at 62 produces $2,100/month and starts immediately; claiming at 70 produces $3,720/month and starts 8 years later. Total lifetime benefits cross at age 80-82 depending on cost-of-living adjustments. Live past 82 and the 70-claim wins; die before, the 62-claim wins. For married couples, the higher earner's claim age also sets the surviving-spouse benefit for whoever lives longest, which usually means the higher-earning spouse should defer regardless of personal break-even math. Outside of life-expectancy considerations, the tax-bracket optimization matters: SS benefits are partially taxable based on combined income, and claiming SS while doing Roth conversions can push combined income into ranges where 85% of benefits become taxable. Best practice for high earners: claim at 70, do Roth conversions in the 60-69 window before SS starts.

Roth conversion ladders for early retirement

A Roth conversion ladder converts Traditional IRA assets to Roth in $30K-$80K chunks over 5+ years, paying the tax now to enable tax-free withdrawals later. The 5-year rule lets you withdraw converted principal (not earnings) penalty-free five years after conversion, regardless of age. The classic use case is someone retiring at 50-55 who has built up large Traditional balances and needs accessible cash before age 59.5. By converting $50K per year from age 50 through 55, they create five "tranches" that become accessible at ages 55-60 without penalty. Each conversion is taxed at the marginal rate that year, so doing the conversion in the years between W-2 income ending and Social Security/RMDs starting is the cheapest window. Filling the 12% and 22% brackets in those years can produce $200K-$500K of tax-free retirement income at conversion rates that would have been 32-35% if the conversions happened during peak earning years. Convert too much in one year and you can trigger IRMAA Medicare premium surcharges later (the IRMAA lookback is two years), in which case the conversion's apparent tax cost understates the true cost. The conversion math gets complicated fast; modeling it properly is one of the highest-leverage exercises in retirement planning.