Retirement Savings Calculator
Project your retirement nest egg from current savings and monthly contributions, see it in today’s dollars, find out how much you need for the income you want and how long your savings will last.
How it works
Each month: balance = balance × (1 + r) + contribution, r = annual return ÷ 12 · Today’s dollars = balance ÷ (1 + inflation)^years · Nest egg needed = Σ first withdrawal × (1 + monthly inflation)^k ÷ (1 + retirement return ÷ 12)^k over the months of retirement
Your current savings and every monthly contribution compound at the monthly return until you retire, and contributions can rise by a set percent each year. Because growth builds on prior growth, the final years add the most. The balance is shown in future dollars and in today’s dollars (divided by inflation over the same years), which is how you should compare it with your budget today. For the retirement side, the calculator takes the monthly income you want, subtracts other income such as Social Security or a pension, and raises the gap with inflation until you retire. It then works out the nest egg that could pay that gap every month, still rising with inflation, until the age you plan for, while the rest of the money earns the retirement return. It compares that with your projected balance, shows the monthly contribution that would close any shortfall, and runs the withdrawals month by month to show when the money would run out. The return you assume matters more than any other input, so try a range rather than a single number.
Worked example
At age 30 with $20,000 saved, adding $500 a month at a 7% return until 65 grows to about $1,130,650 — $230,000 of contributions and about $900,650 of growth. With 3% inflation that is about $401,800 in today’s dollars. Wanting $4,000 a month in today’s money with $1,500 from Social Security leaves a $2,500 gap, which grows to about $7,035 a month by age 65. Paying that, rising with inflation, until 90 at a 5% return needs a nest egg of about $1,656,000, so the plan is about $525,000 short; saving about $792 a month instead of $500 would close the gap. On the current plan the money would last until about age 80.
Sources: Investor.gov (SEC) — Retirement planning tools · Social Security Administration — Estimate your benefits
Frequently asked questions
What return should I assume?
A diversified stock-heavy portfolio has historically returned roughly 9–10% a year before inflation over long periods, or about 6–7% after inflation, with big swings from year to year. Many planners use 5–7% before retirement and a lower rate in retirement, when portfolios usually hold more bonds.
Is this in today’s dollars?
The main balance is in future dollars, but the calculator also shows it in today’s dollars using the inflation rate you enter. Today’s dollars are the better guide to what the money will buy.
How much do I actually need to retire?
Enter the monthly income you want in today’s money and your other income, such as Social Security or a pension. The calculator works out the nest egg that covers the gap until the age you plan for, with the gap rising each year with inflation. A common rule of thumb is 25 times the yearly amount you need from savings, which matches the 4% withdrawal rule.
What if I’m behind?
The calculator shows the monthly contribution that would close the shortfall. Other levers are retiring a few years later (more saving years and fewer withdrawal years), raising contributions each year with pay rises, or planning for a lower income in retirement.
Are taxes included?
No. All figures are before tax. Withdrawals from traditional 401(k)s and IRAs are taxed as income, so set your income goal before tax or leave a margin for it.
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This is an educational estimate, not financial advice. Confirm figures with your lender, advisor or tax professional.