How this calculator works
Retirement math is a tug-of-war. On one side, your portfolio keeps earning returns on whatever's still invested. On the other, you pull money out every year — and because prices rise, you have to pull out a little more each year just to keep the same lifestyle. Whether your money lasts comes down to which force wins, and for how long. This tool plays out that tug-of-war year by year, from the age you retire to the age you plan for, and shows you the balance at every step.
It starts from the famous 4% rule: withdraw 4% of your savings in year one, raise that dollar amount with inflation thereafter, and history suggests the money lasts roughly 30 years. But that's a rule of thumb, not your situation. Your returns, your inflation, your time horizon, and any Social Security or pension income all change the answer — and a pension that covers part of your spending can extend a portfolio dramatically, because you're drawing far less from it each year.
The method
Each year, the calculator subtracts your inflation-adjusted withdrawal (net of other income), then grows what remains by your expected return:
It repeats until either your time horizon is reached — showing the leftover balance — or the balance hits zero, showing the exact age your money runs out. It also solves for the maximum spending that would let your money last the full horizon.
- Withdrawal rate: spending ÷ nest egg =
4.0%— the textbook starting point. - Early on, investment growth roughly keeps pace with the rising (inflation-adjusted) withdrawals.
- Money lasts to about age 99, clearing your plan horizon.
- Other income matters: add $24,000 of Social Security and you draw far less from the portfolio.
Acronyms used on this page
- SS
- Social Security
The risks a simple model can't show
This is a steady-return projection — it assumes the same return every year. Real markets don't oblige, and the order of returns matters enormously: a crash in your first few retirement years (so-called sequence-of-returns risk) does far more damage than the same crash later, because you're selling assets while they're down. Treat a comfortable result here as necessary but not sufficient, build in a buffer, and stay flexible about spending in down years. A safe withdrawal rate is a starting discipline, not a licence to ignore the markets.
Frequently asked questions
What is the 4% rule?
Withdraw 4% of your portfolio in year one, adjust that amount for inflation each year, and historically the money lasts ~30 years. It's a guideline, not a guarantee — your returns, horizon, and other income change it.
How long will my savings last?
It depends on withdrawals, returns, inflation, and pension/Social Security income. This tool simulates year by year and shows the age your money runs out or how much remains at your horizon.
What's a safe withdrawal rate?
Often 3.5–4% of the starting balance for a 30-year retirement, lower for longer horizons or conservative portfolios. The calculator computes your personal maximum so the money lasts your full plan.
Does this guarantee my money lasts?
No. It uses a constant return and excludes taxes and market crashes' timing (sequence risk). It's a planning estimate — build in a safety margin and revisit it as markets and spending change.