Ask ten people how much they need to retire and you’ll get ten different answers — most of them guesses. The truth is there’s a well-established formula behind this number, and once you know it, you can calculate your own target in about five minutes.
Here’s how much you actually need, how to get there from where you are today, and the mistakes that derail people most often.
The 4% Rule — The Most Popular Retirement Formula
The 4% rule, originating from research on safe withdrawal rates, suggests that if you withdraw 4% of your retirement portfolio in your first year of retirement (adjusting for inflation each year after), your savings should reasonably last 30 years in most historical market scenarios.
To use it in reverse and find your target number:
Retirement Number = Annual Spending Need ÷ 0.04 (or simply, Annual Spending × 25)
If you expect to need $50,000/year in retirement, you’d need approximately:
$50,000 ÷ 0.04 = $1.25 million
How to Use a Retirement Calculator (Step-by-Step)
A retirement calculator generally needs five inputs:
- Current age
- Target retirement age
- Current retirement savings
- Monthly contribution amount
- Expected annual rate of return
From there, it projects your balance forward using compound growth, similar to how a savings or investment calculator works, but typically over a much longer multi-decade timeline.
Real Example: 35-Year-Old Starting with $30,000
Let’s project a realistic scenario:
- Current age: 35
- Retirement age: 65 (30 years to grow)
- Current savings: $30,000
- Monthly contribution: $500
- Expected annual return: 7%
Growing the existing $30,000 alone over 30 years at 7% gets you to roughly $243,000. Adding the $500/month contribution compounding alongside it adds another ~$610,000.
Projected total balance at 65: approximately $850,000
That’s a strong outcome from a modest starting point — but it also shows how heavily the monthly contribution, not just the starting balance, drives the final number over a multi-decade horizon.
How Much Should You Have Saved by Each Age? (Common Benchmarks)
Several major financial firms, including Fidelity, publish age-based savings benchmarks, generally expressed as a multiple of your current salary. A commonly cited rough guide:
- By 30: ~1× your annual salary
- By 40: ~3× your annual salary
- By 50: ~6× your annual salary
- By 60: ~8–10× your annual salary
- By 67: ~10–12× your annual salary
These are general benchmarks, not personal targets — your actual number depends heavily on your expected retirement lifestyle, other income sources, and retirement age.
401k vs Roth IRA — Which One Should You Prioritize?
- Traditional 401(k): Contributions are pre-tax, lowering your taxable income now; withdrawals in retirement are taxed as ordinary income. Often comes with an employer match — free money you should generally capture first.
- Roth IRA: Contributions are after-tax, but qualified withdrawals in retirement — including all growth — are completely tax-free.
A common strategy: contribute enough to your 401(k) to get the full employer match, then max out a Roth IRA if eligible, then return to the 401(k) for additional savings.
Social Security — Can You Count on It?
Social Security is projected to remain a meaningful income source for retirees, though the trust fund’s long-term funding has faced ongoing policy discussion, and benefit levels may be adjusted in the future. Most financial planners recommend treating Social Security as a supplement to personal retirement savings rather than a sole retirement plan.
The Biggest Retirement Mistakes People Make in Their 40s
- Pausing contributions during high-expense years (kids, mortgage) instead of scaling them down modestly
- Being too conservative too early, missing out on decades of potential growth
- Not increasing contributions as income rises over a career
- Cashing out a 401(k) when changing jobs instead of rolling it over — the CFPB’s retirement resources explain how to handle a rollover correctly
See your personalized retirement number. Use the Retirement Calculator →
Frequently Asked Questions
How much should I save per month for retirement?
A common guideline is saving 15% of gross income for retirement, including any employer match, starting as early as possible — though the right number depends on your target retirement age and desired lifestyle.
Can I retire on $500,000?
It’s possible, particularly with a lower annual spending need, other income sources like Social Security or a pension, or a paid-off home, but under the 4% rule, $500,000 would support roughly $20,000/year in sustainable withdrawals on its own.
What is the average retirement savings at 50?
Savings vary widely, but many benchmarks suggest aiming for roughly 6 times your annual salary by age 50 as a general target, adjusted for your personal retirement goals.
How does inflation affect retirement planning?
Inflation erodes purchasing power over time, which is why most retirement projections use an inflation-adjusted (real) rate of return and why the 4% rule specifically accounts for annual inflation adjustments to withdrawals.