Retirement planning has a reputation for being complicated, and most financial guidance doesn’t help — it’s either vague (“save more!”) or so detailed that you need a finance degree to understand it. This guide cuts through the noise with clear numbers.

The core question: how much is enough?

Before you can know how much to save, you need to know how much you’ll need.

The most widely used starting point is the 25x rule: take the annual income you want in retirement, and multiply by 25. That’s your target nest egg.

The logic comes from the 4% rule — research from the Trinity Study that found a portfolio of 60% stocks / 40% bonds could sustain annual withdrawals of 4% for 30+ years with a very high success rate.

Example

You currently spend $70,000 per year. In retirement, you think you’ll need around $60,000 (maybe lower rent, no commuting costs, no saving contributions).

$60,000 × 25 = $1,500,000 is your target.

At a 4% withdrawal rate: $1,500,000 × 4% = $60,000 per year, or $5,000 per month.

How much should you save each month?

The answer depends on three variables: how much you’ve already saved, your expected rate of return, and years until retirement.

Here are some approximate monthly savings needed to reach a $1,000,000 nest egg, assuming 7% average annual return:

Starting balanceStarting age (retire at 65)Monthly saving needed
$025~$380/month
$035~$820/month
$045~$2,100/month
$50,00035~$570/month
$100,00035~$330/month

Starting earlier means dramatically lower monthly contributions. The difference between starting at 25 vs 35 is nearly $500/month for the same target.

Use the retirement calculator to model your exact scenario →

The “10–15% of income” rule of thumb

Many financial advisors suggest saving 10–15% of your gross income for retirement. This is a practical starting point, not a magical formula.

10% works well if:

  • You start early (25–30)
  • Your employer matches contributions
  • You expect to have other income in retirement (pension, part-time work)

15%+ is better if:

  • You’re starting later
  • You have an aggressive retirement lifestyle in mind
  • You want a larger safety margin

Maximise tax-advantaged accounts first

Before anything else, contribute to accounts that reduce your tax bill:

  1. 401(k) up to the employer match — this is free money. If your employer matches 4%, contribute at least 4%.
  2. IRA / Roth IRA — up to $7,000/year (2025 limit; $8,000 if you’re 50+). A Roth IRA grows tax-free.
  3. 401(k) beyond the match — up to $23,500/year (2025 limit).

The combination of employer matching, tax-deferred growth, and compound interest inside these accounts dramatically outperforms taxable investing.

The impact of fees

Investment fees are silent killers of retirement savings. A 1% annual management fee reduces your ending balance by roughly 20-25% over 30 years.

Example:

  • $500/month for 30 years at 7%: $567,000 with no fees
  • Same scenario with 1% annual fee: ~$440,000

The difference: $127,000 — purely from fees.

Low-cost index funds (expense ratios of 0.03–0.10%) beat high-fee actively managed funds over long periods in study after study.

Benchmarks by age

Use these as rough checkpoints, not strict rules. Based on saving 15% of income from age 22 with typical returns:

AgeSavings target
301× annual salary
352× annual salary
403× annual salary
506× annual salary
608× annual salary
6710× annual salary

(Fidelity’s broadly cited benchmarks)

If you’re behind these benchmarks, don’t panic — catching up is possible. Increase your contribution rate, delay retirement slightly, or consider a part-time transition rather than a hard stop.

Don’t forget Social Security

For most US workers, Social Security will provide 20–40% of pre-retirement income. That meaningfully reduces the nest egg you need from investments.

You can check your estimated Social Security benefit at ssa.gov/myaccount. Factor it in when calculating your target withdrawal rate.

Get your numbers

Use our free retirement savings calculator to model your specific situation — current savings, monthly contributions, expected return rate, and years to retirement. You’ll see the projected nest egg, the monthly income it could provide, and a year-by-year growth chart.