Retirement planning has one master question: How much money do I need to stop working and never run out? The answer is not a fixed number — it is a calculation that depends on your lifestyle, retirement age, investment returns, inflation rate, and life expectancy. But there is a proven framework for finding your number.
The 4% Rule: Your Retirement Starting Point
The most widely cited retirement guideline is the 4% rule, derived from the Trinity Study (Cooley, Hubbard, and Walz, 1998):
If you withdraw 4% of your portfolio in the first year of retirement, then adjust that amount for inflation each subsequent year, your portfolio has a 95% probability of lasting 30 years.
The implication:
Retirement Number = Annual Expenses × 25
If you need $60,000 per year to cover your living costs: Retirement number = $60,000 × 25 = $1,500,000
If you need $40,000 per year: Retirement number = $40,000 × 25 = $1,000,000
This 25× multiplier is simply 1 ÷ 4% rearranged. It is a starting point — adjustments are required based on your personal situation.
How Retirement Age Changes Your Target
The 4% rule was designed for a 30-year retirement. If you retire early (at 50 or 55), you may need your portfolio to last 40–45 years — which requires a lower withdrawal rate and a larger starting balance.
| Planned Retirement Duration | Safe Withdrawal Rate | Savings Multiple |
|---|---|---|
| 20 years (retire at 65, live to 85) | 5.0% | 20× expenses |
| 25 years (retire at 60, live to 85) | 4.5% | 22× expenses |
| 30 years (retire at 55, live to 85) | 4.0% | 25× expenses |
| 35 years (retire at 50, live to 85) | 3.5% | 29× expenses |
| 40 years (retire at 45, live to 85) | 3.0% | 33× expenses |
A 45-year-old aiming to retire on $60,000/year needs: $60,000 × 33 = $1,980,000
Retirement Savings Benchmarks by Age
These milestones, commonly cited by Fidelity and Vanguard, assume a target of replacing 80% of pre-retirement income at age 67:
| Age | Savings Target (Multiple of Annual Salary) |
|---|---|
| 30 | 1× your annual salary |
| 35 | 2× your annual salary |
| 40 | 3× your annual salary |
| 45 | 4× your annual salary |
| 50 | 6× your annual salary |
| 55 | 7× your annual salary |
| 60 | 8× your annual salary |
| 67 (retirement) | 10× your annual salary |
Example: If you earn $70,000/year, by age 50 you should have approximately $420,000 saved (6× salary). By retirement, aim for $700,000 (10× salary).
These benchmarks assume consistent investing from your 20s and are calibrated to US Social Security/pension supplement realities. Adjust upward if you expect no pension income.
How Investment Returns Change Your Target Timeline
The time it takes to reach $1.5M depends enormously on your savings rate and investment return:
| Monthly Savings | 5% Return | 7% Return | 10% Return |
|---|---|---|---|
| $500/month | 59 years | 47 years | 36 years |
| $1,000/month | 50 years | 41 years | 31 years |
| $2,000/month | 41 years | 34 years | 26 years |
| $3,000/month | 36 years | 30 years | 23 years |
| $5,000/month | 29 years | 26 years | 20 years |
Assuming starting from $0. Target: $1,500,000.
The difference between a 5% and 10% average annual return can cut the time required by more than a decade on the same savings rate. This is why investment allocation matters as much as how much you save.
The Inflation Factor
$60,000 in today's purchasing power will cost more in the future. At 3% average inflation:
| Years to Retirement | Amount Needed in Future Dollars |
|---|---|
| 10 years | $60,000 × 1.343 = $80,600 |
| 20 years | $60,000 × 1.806 = $108,400 |
| 30 years | $60,000 × 2.427 = $145,600 |
This means if you are 30 years away from retirement and need $60,000 in today's dollars, your actual income requirement at retirement will be closer to $145,600/year in nominal terms. Your portfolio needs to be sized for the inflated figure.
What Reduces Your Retirement Number
Several income sources can reduce how much you need to accumulate:
| Income Source | How It Reduces Your Target |
|---|---|
| State pension / Social Security | Each $1,000/month in pension income reduces portfolio need by $300,000 (at 4% rule) |
| Employer pension | Same calculation — convert annual pension to lump-sum equivalent |
| Part-time work in retirement | Even $10,000/year reduces portfolio withdrawals and extends portfolio life significantly |
| Property rental income | Reliable rental income reduces dependence on portfolio withdrawals |
| Paid-off home | Eliminates rent/mortgage from expenses, lowering the required annual income |
The Real Retirement Plan: What to Do Now
If you are 20–30: Prioritise starting. Even small amounts compounding over 40 years outperform large amounts saved too late.
If you are 30–45: Ensure you are savings-rate efficient. The industry rule of thumb is saving 15% of gross income for retirement (including employer contributions).
If you are 45–55: Maximise contributions, reduce high-interest debt, and model different retirement age scenarios. Consider professional financial advice.
If you are 55+: Focus on sequence-of-returns risk — being heavily in equities just before retirement exposes you to the worst possible scenario (a market crash in the 1–3 years before or after you retire). A glide path toward bonds/cash reduces this risk.
Calculate Your Retirement Number
Use our Retirement Calculator to model your personalised retirement number based on your current savings, monthly contributions, expected return, and target retirement age. You can also use the Compound Interest Calculator to model the growth of your current savings over any time horizon.
This article is for educational purposes only and does not constitute financial advice. Retirement planning involves complex personal variables — consult a qualified financial planner for personalised guidance.
Frequently Asked Questions
Q: How much money do I need to retire according to the 4% rule? A: Retirement Number = Annual Expenses × 25. For example, someone needing $60,000 per year in retirement should target a portfolio of $1,500,000, based on the Trinity Study's finding that a 4% first-year withdrawal rate has a 95% chance of lasting 30 years.
Q: How does retiring early change how much I need to save? A: A longer retirement requires a lower safe withdrawal rate and a bigger savings multiple — for example, a 30-year retirement uses a 4.0% withdrawal rate and 25× expenses, while a 40-year retirement (retiring at 45) drops to a 3.0% withdrawal rate and requires 33× expenses.
Q: How much should I have saved for retirement by age 50? A: Benchmarks commonly cited by Fidelity and Vanguard suggest having about 6× your annual salary saved by age 50, rising to 10× your salary by retirement at 67. For example, someone earning $70,000/year should have roughly $420,000 saved by 50.
