Retirement Number Calculator
Most retirement calculators ask what you'll save. This one starts from what you'll actually spend, then works backward to the one number that matters: the annual growth rate you need to get there in time.
Last reviewed September 2026 · How this calculator works
Your "retirement number" isn't a generic multiple of your salary — it's the specific amount of invested assets that, combined with Social Security and any pension, can cover what you actually plan to spend. This page explains how that number is calculated, walks through a real example, and gives you a free calculator to find your own.
What is your "retirement number," really?
Most rules of thumb — "save 25 times your income," "aim for $1 million" — assume your retirement spending scales neatly with your salary. It often doesn't. Someone earning $150,000 who plans to live on $50,000 a year in retirement needs a very different nest egg than someone earning $80,000 who wants the same lifestyle they have now. The more accurate approach, and the one this calculator uses, works backward from three real numbers: what you'll actually spend each month in retirement, what guaranteed income you'll already have (Social Security, a pension), and what rate of return you expect your invested assets to pay you once you're living off them. The gap between spending and guaranteed income, divided by your target income rate, is your retirement number.
How much should you have saved by 45? A worked example
Rule-of-thumb charts often say something like "have 4-6 times your salary saved by 45." Here's what working backward from actual expenses looks like instead, using the calculator's default inputs — a 45-year-old planning to retire at 62 with $6,000/month in total retirement spending, $2,000/month in expected Social Security, a 5% target income rate, $20,000 already saved, and $600/month in ongoing contributions:
- Monthly shortfall: $4,000 ($6,000 in spending minus $2,000 in Social Security)
- Retirement number at a 5% income rate: $960,000 ($48,000 annual shortfall ÷ 5%)
- Years to retirement: 17
- Required annual growth rate to close the gap: about 16.3% — a genuinely aggressive number, well outside what a typical diversified portfolio delivers
Your retirement number at different income rates
The income rate you assume during retirement — how much your invested assets pay you each year once you stop working — changes your target number substantially. Using the same $48,000 annual shortfall from the example above:
| Assumed income rate | Retirement number needed |
|---|---|
| 3% (very conservative — bonds, cash-heavy) | $1,600,000 |
| 3.5% (updated "safe withdrawal rate" guidance) | $1,371,000 |
| 4% (the classic "4% rule") | $1,200,000 |
| 5% (this calculator's default) | $960,000 |
| 6% (more aggressive — dividend growth, real estate) | $800,000 |
A lower assumed income rate is more conservative and requires a bigger nest egg, but it's also more likely to survive decades of market volatility. A higher rate needs less saved upfront but leaves less room for error if returns disappoint. There's no universally "correct" rate — it depends on your asset mix, risk tolerance, and how flexible your spending can be if markets underperform.
Monthly expenses in retirement
Expected retirement income
Your income rate goal
Time and current savings
Your retirement number
If your required growth rate looks too high
A required rate north of 10-12% doesn't mean retirement is out of reach — it means the current combination of inputs doesn't add up yet, and something needs to move. In practice, there are four honest levers, and most people end up adjusting a mix of them rather than leaning on just one:
- Save more each month. Even a modest increase compounds meaningfully over a decade or more — rerun the calculator with a higher contribution to see the effect.
- Push the retirement age out. A few extra years both adds contributions and gives existing assets more time to compound, often lowering the required rate substantially.
- Reduce the target spending. Trimming discretionary spending in the plan (not necessarily in real life today) lowers the retirement number directly.
- Accept more investment risk — carefully. A higher-growth strategy can close the gap, but it should be a deliberate choice made with an understanding of the added volatility, not a hope.
Related guides
- How Much Do I Need to Retire? The 4% Rule, Explained Honestly
- Sequence-of-Returns Risk: Why the Order of Returns Matters in Retirement
- Inflation and Retirement: How to Plan in Today's Dollars
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Frequently asked questions
How much money do I actually need to retire?
It depends on your expenses in retirement, any income you'll already have (Social Security, a pension), and what return you expect your investments to earn once you're living off them. The formula: annual income gap ÷ expected income rate. A $40,000 annual gap at a 5% income rate means roughly $800,000 invested. There's no single number that applies to everyone.
What is a good rate of return to assume for retirement planning?
For the rate your assets pay you during retirement, conservative dividend stocks and bonds typically run 2-5%, while real estate or a mixed portfolio might support 5-8%. For the growth rate needed to build your nest egg beforehand, it depends entirely on your savings, timeline, and monthly contributions — that's what this calculator solves for.
What if my required growth rate is unrealistically high?
A high required rate is information, not a verdict. Your real levers are saving more each month, retiring later, spending less in retirement, or accepting a more aggressive investment strategy. Most people end up adjusting some combination of all four.
Is the 4% withdrawal rule still valid?
It's a reasonable starting point, though many planners now suggest 3-3.5% given lower expected future returns and longer lifespans. This calculator lets you set your own target income rate rather than assuming one fixed number.
Should I use essential expenses or total expenses in this calculator?
Use your total expected retirement spending — essentials like housing and healthcare plus discretionary spending like travel and hobbies. Leaving out the discretionary side tends to produce a number that looks achievable on paper but doesn't match the retirement you actually want.
How much should I have saved for retirement by age 45?
There's no single correct figure — common rule-of-thumb guidance suggests 4-6 times your annual salary saved by 45, but that ignores how much you actually plan to spend in retirement. What matters more than hitting a generic benchmark is working backward from your own expected expenses and retirement age, which is what this calculator does instead of relying on a one-size-fits-all multiple.
Why does this calculator ask for expenses instead of just a savings multiple like 25x income?
Rules like "save 25 times your income" assume everyone's retirement spending scales with their salary, which often isn't true — someone earning $150,000 who plans to spend $50,000 a year in retirement needs a very different number than the 25x-income rule would suggest. Starting from actual projected expenses, minus expected guaranteed income like Social Security, produces a number tailored to how you actually plan to live, not a generic multiple of your paycheck.