Personal Updated May 20, 2026 🕐 3 min read ✓ Verified

How to Calculate Your Financial Freedom Number

Your financial freedom number is the invested portfolio size that, based on historical evidence, can sustain your lifestyle indefinitely without depleting the capital. It is calculated as 25 times your annual expenses — derived from the 4% safe withdrawal rate. Knowing this number gives you a concrete, quantifiable target for financial independence.

financial-independence fire retirement savings 4-percent-rule

Quick reference

Financial freedom number
Annual expenses × 25
Based on 4% safe withdrawal rate
Annual expenses 30.000
750.000 target
4% of 750.000 = 30.000 per year
Annual expenses 50.000
1.250.000 target
4% of 1.250.000 = 50.000 per year
Historical success rate
~96% over 30 years
US stock/bond portfolio — varies by period

The 4% rule — the foundation of the number

The 4% rule originates from William Bengen's 1994 research and the subsequent Trinity Study (1998). These researchers examined historical US stock and bond returns from 1926 onwards and asked: what is the maximum annual withdrawal from a portfolio, expressed as a percentage of the initial balance, that never depleted the portfolio over any 30-year period in the historical record?

The answer was 4%. A portfolio invested 50% in US stocks and 50% in intermediate bonds could sustain 4% annual withdrawals — adjusted upward for inflation each year — for 30 years across essentially all historical periods tested. The rare failures occurred during the worst periods of market history (retiring just before the Great Depression or the 1970s stagflation).

Inverting 4% gives 25. If 4% of your portfolio covers your annual expenses, your portfolio is 25 times your annual expenses. This is the financial freedom number — the capital base at which you can, with high historical probability, live off your investments indefinitely without working.

For FIRE (Financial Independence, Retire Early) purposes — where the retirement period may be 40 to 60 years rather than 30 — some researchers recommend a lower withdrawal rate of 3 to 3,5%, implying a financial freedom number of 28,6 to 33 times annual expenses. The 4% rule was derived for a 30-year retirement; longer periods carry more sequence-of-returns risk.

Financial freedom number formula

Formula
\text{FI Number} = \text{Annual Expenses} \times 25
Multiply your total annual living expenses by 25. The result is the invested portfolio size required to sustain your lifestyle indefinitely at the 4% withdrawal rate. Use actual annual expenses — not income — because what matters is the spending level you need to maintain.
Annual ExpensesTotal annual spending required to maintain your desired lifestyle — all costs including housing, food, transport, insurance, healthcare, entertainment
25The multiplier derived from the 4% withdrawal rate (1 ÷ 4% = 25)
FI NumberThe invested portfolio size required for financial independence at the 4% withdrawal rate

Worked examples

Example 1Netherlands couple — modest lifestyle
Given: Annual expenses: 36.000 (3.000/month) | Includes: rent 14.400, food 7.200, transport 3.600, insurance 2.400, healthcare 2.400, leisure 3.600, miscellaneous 2.400
Result: FI number: 900.000 | At 7% real return and 25% savings rate (net income 4.000/month): 25 years to reach

FI number: 36.000 x 25 = 900.000. With net income 4.000/month and expenses 3.000, savings = 1.000/month = 12.000/year. At 7% real investment return, time to 900.000 from zero: approximately 27 years. Increasing savings to 1.500/month reduces timeline to approximately 22 years. Note: Dutch state pension (AOW) from age 67 reduces the required FI number for those planning to retire at traditional age — AOW of approximately 14.000 per year covers nearly 40% of the example expenses.

Example 2High earner — higher expense target
Given: Annual expenses: 72.000 (6.000/month) | Savings: 2.500/month | Investment return: 7% real
Result: FI number: 1.800.000 | Time from zero: approximately 28 years

FI number: 72.000 x 25 = 1.800.000. Annual savings: 30.000. At 7% real return, 1.800.000 from zero takes approximately 28 years. Increasing savings to 3.500/month (42.000/year) reduces timeline to approximately 24 years. The absolute FI number is higher but the timeline is similar because the savings rate (savings/income) determines the speed, not the absolute amount.

Example 3Lean FIRE — minimum viable expenses
Given: Annual expenses: 24.000 (2.000/month) | Aggressive savings: 2.000/month
Result: FI number: 600.000 | Time from zero: approximately 16 years

FI number: 24.000 x 25 = 600.000. Saving 2.000/month = 24.000/year. At 7% real return: approximately 16 years to 600.000. This is the lean FIRE scenario — a frugal lifestyle with a low FI number combined with a high savings rate produces the shortest timeline. State pension at 67 would further reduce required portfolio or allow higher withdrawal rate.

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FI number by annual expenses and withdrawal rate assumption

Annual Expenses4% rule (×25)3,5% rule (×28,6)3% rule (×33)Notes
20.000500.000571.000667.000Very lean lifestyle
30.000750.000857.0001.000.000Single person, modest
40.0001.000.0001.143.0001.333.000Single, comfortable
50.0001.250.0001.429.0001.667.000Couple, modest
70.0001.750.0002.000.0002.333.000Couple, comfortable
100.0002.500.0002.857.0003.333.000High lifestyle

Common mistakes with the financial freedom number

✗ Using current income rather than current expenses to calculate the FI number
✓ The FI number is based on spending, not income. What you need to sustain is your lifestyle — your expenses. If you earn 80.000 and spend 45.000, your FI number is 45.000 x 25 = 1.125.000, not 80.000 x 25 = 2.000.000. Using income dramatically overstates the required portfolio and makes financial independence seem further away than it is.
✗ Not accounting for the Dutch AOW state pension
✓ Dutch residents who have lived in the Netherlands for the required period receive AOW (Algemene Ouderdomswet) state pension from age 67. In 2025, the single-person AOW is approximately 1.270 per month (15.240 per year) and the couple rate is approximately 875 per person per month. If your financial plan includes drawing AOW from 67, the required portfolio pre-67 can be reduced because the AOW will cover part of annual expenses from that point.
✗ Ignoring sequence-of-returns risk for early retirees
✓ The 4% rule was tested for 30-year periods. For early retirees with 40 to 50-year horizons, the failure rate increases and a more conservative 3 to 3,5% withdrawal rate is prudent. A 10 to 15% larger portfolio provides significantly more resilience against a bad sequence of early returns — which is the single biggest risk to a long retirement. Consider working part-time for the first few years of retirement to allow the portfolio to compound before drawing from it.

Methodology

FI number calculated as annual expenses divided by the safe withdrawal rate. 4% withdrawal rate from Bengen (1994) and Trinity Study (1998). Years to FI calculated using future value formula with annual contributions at stated real investment return. AOW figures from SVB (Sociale Verzekeringsbank) 2025 rates.

The 4% rule is based on US historical data. European investors should note that European stock market returns have historically been lower than US returns in some periods. A conservative European FIRE investor may prefer a 3 to 3,5% withdrawal rate and FI number of 28 to 33 times annual expenses.

Cite this guide
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https://calquify.com/guides/how-to-calculate-financial-freedom-number
Last updated: May 2026

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Frequently asked questions

Does the 4% rule account for inflation?
Yes — and this is critical to understand. The 4% rule allows you to withdraw 4% of the initial portfolio value in year one, then increase that amount by inflation every subsequent year. So if you have a 1.000.000 portfolio and withdraw 40.000 in year one, and inflation is 3%, you withdraw 41.200 in year two, 42.436 in year three, and so on. The portfolio must therefore grow both to cover withdrawals and to keep pace with inflation — which is why the 50/50 stock/bond portfolio is assumed, as bonds provide stability and stocks provide the inflation-beating growth.
Should I include my home in the FI number?
No — not if you plan to live in it. The FI number is based on investable assets that generate returns. A home you live in does not generate cash income (though it does reduce rent expense, which is a benefit). Exclude the primary residence from your portfolio calculation. If you own investment properties that generate net rental income, you can reduce your FI number by the annual net rental income capitalised appropriately — or simply count the net rental income as covering part of annual expenses.
What investment return should I assume for the FI calculation?
A 5 to 7% real (after inflation) annual return is the standard assumption for a globally diversified stock portfolio based on long-run historical data. Use 5% for conservative planning and 7% for base case. For a mixed stock/bond portfolio (which many retirees hold for stability), 4 to 5% real is more appropriate. Avoid using nominal returns — what matters for calculating how long your money lasts is real (inflation-adjusted) return, since you are also increasing withdrawals with inflation.
Sources & References
› Bengen WP — Determining Withdrawal Rates Using Historical Data, Journal of Financial Planning, 1994 Retrieved 2026-05-20
› Trinity Study — Cooley, Hubbard, Walz — Retirement savings: choosing a withdrawal rate that is sustainable, 1998 Retrieved 2026-05-20

Formula based on standard mathematical and financial methods. Results are for informational purposes. Last reviewed May 2026. Version 1.