How much do I need to retire?
The most common starting answer in US personal finance is 25 times your expected annual retirement spending. This shortcut comes from the 4% rule, derived from the 1998 Trinity Study (Cooley, Hubbard, Walz, Trinity University): historically, withdrawing 4% of an initial balanced US portfolio in year one and adjusting that dollar amount for inflation each year would have lasted at least 30 years in nearly all historical periods.
The shortcut works because 1 ÷ 0.04 = 25. If a 4% withdrawal rate is sustainable, then any amount you want to withdraw safely must be 25 times that figure. Scroll up and plug your numbers into the retirement calculator to see your target updated in real time.
How this retirement calculator works
- Accumulation. Starting balance compounds monthly at your chosen rate. Your contribution + employer match is added every month until the retirement age you set.
- Effective rate. Annual return is converted to a monthly growth factor:
monthly_growth = (1 + rate)^(1/12) − 1. This matches Excel'sFV()with monthly compounding. - Inflation. When enabled, the projected nest egg is also shown in today's purchasing power:
real = nominal / (1 + inflation)^years. - Safe withdrawal. Annual safe withdrawal = nest egg × SWR (default 4%). Monthly figure is annual ÷ 12.
- Target. Spending gap × 12 ÷ SWR. If SWR is 4%, the multiplier is 25.
Why employer 401(k) match matters so much
An employer 401(k) match is the closest thing to a guaranteed 100% one-year return in personal finance. The default in this calculator ($200/mo match) adds $2,400 per year. Over 35 years at 7% real, that single line item alone is worth roughly $330,000 in today's dollars. If your employer offers a match and you are not capturing it in full, that is the highest-priority fix in your plan — higher than picking the perfect index fund.
For more on the compounding math behind that 35-year figure, see the underlying compound interest calculator, which powers the projection engine on this page.
Real vs nominal returns — which should I use?
If you want results in today's purchasing power, use a real return (about 7% for long-run US stocks per Damodaran's historical S&P data) and turn inflation adjustment off — the nest egg figure is already in today's dollars. If you want the raw future-dollar number, use a nominal return (about 10%) and turn inflation on to see the today's-dollar equivalent below the headline. Either method produces the same real result.
Is the 4% rule still safe in 2026?
The original 4% rule assumed a 30-year retirement, a 50/50 stock/bond portfolio, and US historical returns from 1926-1995. Updated research has refined the figure: Bengen (2020) raised it to ~4.7% after adding small-cap value tilts; Morningstar's 2024 "State of Retirement Income" report lowered it to ~3.7% given current bond yields and stock valuations. The calculator above lets you set any safe withdrawal rate between 2% and 8%, so you can stress-test your plan against either view.
Retiring before 65 (early retirement / FIRE)
For early retirement scenarios (FIRE, Coast FIRE, Barista FIRE), two adjustments matter. First, Social Security cannot be claimed before age 62, with full benefits only at 67 for anyone born after 1960 — reduce the SS field accordingly. Second, the 4% rule was tested for 30-year horizons; a 40- or 50-year retirement should use a lower SWR (typically 3.0-3.5%). Set the SWR field to 3.3% and run the projection again to see the impact on your target nest egg.