How to use the retirement calculator
Enter your age, when you want to retire and how long you want the money to last. Add what you have saved for retirement across all accounts, what you put in each month (with any employer match) and how much you expect to raise that amount each year.
Then describe retirement itself: the yearly income you want, in today's dollars, and what Social Security or a pension should pay, also in today's dollars. The calculator grows both with inflation, works out the gap your savings must fill each year, and compares the savings you are on course for with the savings that gap requires. Nothing you type leaves your device.
This page plans across all your accounts. To model one workplace plan with an employer match formula and the 2026 limits, use the 401(k) calculator; for tax-free growth and the income phase-out, use the Roth IRA calculator.
How the calculation works
The saving years are a month-by-month projection: each month your balance earns the return before retirement and your contribution is added, and the contribution steps up once a year. This is compound growth, where earnings are added to the balance and then earn returns themselves (Investor.gov: Compound interest).
For retirement, the calculator finds the lump sum that would pay your income gap every month from your retirement age to your plan age while the remainder keeps earning the return in retirement. That lump sum is the savings you need. If your projected savings fall short, the extra monthly saving shown is the amount that, invested the same way and raised by the same percentage each year, closes the gap by your retirement date.
Worked example
With the defaults (age 35, $50,000 saved, $750 a month rising 2% a year, 6% returns, retiring at 67), you would have about $1,378,632 at retirement, or $625,583 in today's dollars. You put in $448,043 and growth adds $930,589.
Wanting $60,000 a year with $24,000 from Social Security leaves a gap of $36,000 in today's dollars, which is $79,335 in the first year of retirement after 2.5% inflation. Covering that to age 90 at a 4% return needs about $1,534,706. The shortfall is $156,074, so the money would run out at about 87. Saving about $111 more a month closes it: at $861 a month the savings last to about 90.
What changes the result most
Time. Starting at 25 with nothing saved and the same $750 a month gives about $2,140,145 at 67. Starting at 45 with $50,000 gives $655,725.
Returns. Over 32 years, 5% a year gives $1,121,996 and 7% gives $1,704,261. Returns are not guaranteed, so it is sensible to test a lower rate as well as the one you hope for.
Retirement age. Retiring at 70 instead of 67 means more saving years and fewer spending years: the money lasts to about 93. Retiring at 62 it lasts to about 77. These figures keep the same Social Security amount, but in reality the claiming age changes your benefit too.
Social Security and your retirement age
Social Security is often the biggest income source outside savings. You can claim from age 62, but for anyone born in 1960 or later full retirement age is 67, and claiming at 62 cuts the benefit by about 30% (SSA: Retirement age and benefit reduction). Waiting past full retirement age raises it by 8% a year for people born in 1943 or later, until age 70 (SSA: Delayed retirement credits).
Without any Social Security in the example, the savings needed rise to $2,557,844 and the money lasts to about 78. Use the estimate on your own Social Security statement for the age you plan to claim.
How much can you save each year?
For 2026 the IRS lets you defer up to $24,500 into a 401(k), 403(b) or most 457 plans, plus an $8,000 catch-up from age 50 ($11,250 at ages 60 to 63). The IRA limit is $7,500, with a $1,100 catch-up from 50 (IRS IR-2025-111: 2026 401(k) and IRA limits).
If the calculator says you need to save more than you can, the other levers are working a little longer, planning on a lower income, or reducing debt before you retire. See what you take home after tax with the paycheck calculator.
Tips
Think in today's dollars. A million dollars in 30 years buys much less than today. The US inflation calculator shows how prices have changed.
Watch the withdrawal rate. The first-year withdrawal rate is the gap divided by your savings. Higher rates leave less room for poor markets or a long life.
Keep a safe cushion. Money you need in the first years of retirement can sit somewhere steady; compare rates with the high-yield savings calculator.
See compounding on its own. The compound interest calculator shows how a single balance and regular deposits grow.
Taxes are not included. Withdrawals from traditional 401(k)s and IRAs are taxed as income, so plan on a higher gross amount if most of your savings are pre-tax.
Updated October 29, 2026 · Sources are linked in the text above · How we build and check our calculators