Projecting retirement savings without overcomplicating it requires a few honest inputs, realistic assumptions, and some tolerance for uncertainty. The goal is not a precise prediction — it is a useful estimate that tells you whether you are on track and what levers would move the needle most.
The three core variables
Every retirement savings projection depends on three things: how much you save (contributions), how long it grows (time), and at what rate it grows (return). Change any one of them significantly and the ending balance changes dramatically. A practical starting point: use 6-7% as your annual return assumption for a diversified stock-heavy portfolio (roughly the historical real return after inflation). Use your actual planned contribution. Use the time until your planned retirement date. The Retirement Savings Calculator applies this math and shows the projected balance.
Why projections are estimates, not predictions
Markets do not move at a smooth average rate. A portfolio that averages 7% over 30 years might return 20% some years and -30% in others. The sequence of returns matters — large losses early in retirement (when you are drawing down the portfolio) produce much worse outcomes than losses during accumulation (when you are still contributing). A useful approach: run the calculator at 5%, 7%, and 9% returns. The range between conservative and optimistic is the planning window. If even the conservative scenario produces a workable result, you are in good shape.
The 4% withdrawal rule
The 4% rule provides a way to translate a projected balance into projected retirement income: withdraw 4% of the portfolio in year one, then adjust for inflation each subsequent year. A $1,000,000 portfolio supports $40,000/year; $1,500,000 supports $60,000/year. For retirements expected to last 35-40 years, some planners recommend 3-3.5% to increase the margin of safety.
Social Security and other income sources
Social Security retirement benefits supplement savings — for most middle-income workers, benefits replace 30-40% of pre-retirement income. The monthly benefit depends on your earnings history and claiming age. Claiming at 62 reduces benefits by up to 30% vs. full retirement age. Delaying to 70 increases benefits by 8% per year beyond full retirement age. Check your Social Security estimate at ssa.gov. Add this annual income to your portfolio's 4% withdrawal to get total projected retirement income, then compare to your expected spending.
Frequently asked questions
How much should I save each year for retirement?
Fifteen percent of gross income (including any employer match) is the widely cited target for someone starting at 25 who wants to retire around 65. Starting later requires higher rates: at 35, roughly 20-22% to reach the same outcome; at 45, 30%+ to close the gap.
What if I cannot afford 15% right now?
Start with whatever you can — even 5% — and increase by 1% per year or whenever you get a raise. The habit and the account structure matter more in the early years than hitting a specific percentage. Consistent small contributions that increase over time compound to significant balances over a full career.
Sources and review notes
WalletCalcs uses official consumer finance, tax, labor, and banking references where possible. These links support the general educational guidance on this page;.