In Short
A retirement plan compares two numbers: what your savings could grow to by retirement, and the nest egg needed to pay the income you want, less Social Security, until about age 90. A 40-year-old with $75,000 saved, putting in $1,000 a month with the match, could have about $1.39 million at 67 but would need about $1.60 million for $70,000 a year, a gap of $213,000. For 2026 the 401(k) employee limit is $24,500 and the IRA limit is $7,500 [1][2].
How to Use the Retirement Calculator
- Enter your age, the age you'd like to retire, and how long the money needs to last.
- Add what you've saved for retirement, what you put in each month and any employer match.
- Set the income you'd like in retirement in today's dollars, and your Social Security estimate from ssa.gov/myaccount [3].
- Adjust the returns and inflation if you like, or tap Say It All: “I'm 45, I have 120k saved and want to retire at 65, putting away 900 a month.”
The Formula
The calculator grows your savings month by month until retirement, then works out the lump sum that would pay your income gap each year, rising with inflation, until the age you plan to.
- Savings at retirement = savings × (1 + r)^months + monthly saving × ((1 + r)^months − 1) ÷ r, where r = monthly return
- Yearly gap = income wanted − Social Security × 12 (today's dollars), then raised by inflation to your retirement year
- Nest egg needed = the present value of that gap, rising with inflation, for each year of retirement, at your after-retirement return
- Extra monthly saving = shortfall ÷ ((1 + r)^months − 1) × r
Worked Examples
| Scenario | Inputs | Result |
|---|---|---|
| Mid-career, with a match | Age 40, retire at 67, $75,000 saved, $750/month + $250 match, $70,000/yr wanted, $2,000/mo Social Security | $1,388,172 at 67 vs $1,601,195 needed · short $213,023 · about $231/month more |
| Early start, on track | Age 35, retire at 65, $100,000 saved, $1,000/month + $500 match, $60,000/yr wanted, $2,000/mo Social Security | $2,515,404 at 65 vs $1,435,194 needed · on track with $1,080,211 to spare |
| Late start | Age 55, retire at 67, $150,000 saved, $1,000/month, $80,000/yr wanted, $2,200/mo Social Security | $559,293 at 67 vs $1,288,230 needed · about $3,291/month more |
| Self-employed, no match | Age 30, retire at 65, $20,000 saved, $500/month, $60,000/yr wanted, $1,800/mo Social Security | $1,069,238 at 65 vs $1,732,042 needed · about $387/month more |
Illustrative examples, not projections. Figures use the tax year shown and the assumptions above.
How Much Do I Need to Retire?
Start with the income you'd want each year, subtract what Social Security is expected to pay, and the rest has to come from savings. Your personal Social Security estimate is in your my Social Security account [3]; benefits depend on your earnings record and the age you claim.
The nest egg is the lump sum that could pay that gap every year for as long as you plan to live, while the rest stays invested. Planning to 90 or beyond is cautious on purpose: running out at 85 is a bigger problem than having money left over.
The figures at retirement are in future dollars. The calculator also shows them in today's dollars, using your inflation rate, so they're easier to compare with today's prices.
How Much Can I Put in a 401(k) or IRA in 2026?
For 2026, you can defer up to $24,500 of your pay into a 401(k), 403(b) or most 457 plans. At 50 or older you can add a $8,000 catch-up, and at ages 60 to 63 the catch-up is $11,250 instead [1][2].
The IRA limit for 2026 is $7,500, plus $1,100 at 50 or older [2][4]. For 2025 the limits were $23,500 for a 401(k) and $7,000 for an IRA. Switch the tax year above to see either year's limits in your results.
If you work for yourself, a Solo 401(k) or SEP IRA can take much more than an IRA. The Solo 401(k) vs SEP IRA Calculator works out your maximum.
What Return Should I Assume?
Nobody knows future returns, so the calculator uses steady rates you choose: 7% before retirement and 5% after, with 2.5% inflation, by default. Lower returns or higher inflation raise the nest egg you'd need. Try a cautious case and an optimistic one to see the range.
Frequently Asked Questions
How much should I have saved for retirement by 40?
There's no official target. What matters is whether your savings and contributions reach the nest egg your own income goal needs. In the first example above, $75,000 at 40 with $1,000 a month going in gets about 87% of the way to $70,000 a year at 67.
Is $1 million enough to retire?
It depends on the income you want and your Social Security. At a 5% return and 2.5% inflation, $1 million pays roughly $52,600 a year, rising with inflation, for 25 years. Put your own numbers in the calculator above.
What is the 401(k) limit for 2026?
$24,500 of employee deferrals, plus an $8,000 catch-up at 50 or older, or $11,250 at ages 60 to 63. Total contributions from you and your employer can't exceed $72,000 before catch-ups [1][2].
How do I find my Social Security estimate?
Sign in to your my Social Security account at ssa.gov/myaccount to see your personal benefit estimates at different claiming ages [3].
Does this include taxes in retirement?
No. The income you enter is before tax. Withdrawals from traditional 401(k)s and IRAs are taxed as income, and Roth withdrawals generally aren't, so the mix matters.
Sources
- 401(k) limit increases to $24,500 for 2026, IRA limit increases to $7,500 — Internal Revenue Service
- Notice 2025-67: 2026 retirement plan limits — Internal Revenue Service
- my Social Security account — Social Security Administration
- Retirement Topics: IRA Contribution Limits — Internal Revenue Service
Official sources only: the IRS, SSA, BLS and other government agencies. Read how Zentavos researches.