Your FIRE number is the investment portfolio balance that generates enough returns to cover your living expenses indefinitely. Calculating it for Denmark requires accounting for high taxes, limited tax-advantaged accounts, and Danish-specific costs.
The FIRE Number Formula
The core calculation is simple:
FIRE Number = Annual Expenses × 25
This multiplier comes from the 4% rule — the safe withdrawal rate (SWR) derived from the 1998 Trinity Study. Based on US historical data, withdrawing 4% of your portfolio annually has a 95%+ success rate over 30 years, adjusting for inflation each year.
Example
If your annual expenses are DKK 300,000:
DKK 300,000 × 25 = DKK 7,500,000
You need DKK 7.5 million invested to sustain DKK 300,000 per year at a 4% withdrawal rate.
Calculating Your Annual Expenses
List every category of spending for one full month, then multiply by 12:
| Category | Monthly (DKK) | Annual (DKK) |
|---|---|---|
| Rent / mortgage | 8,500 | 102,000 |
| Food and groceries | 3,500 | 42,000 |
| Transport (car, transit, fuel) | 2,000 | 24,000 |
| Utilities (electricity, heating, internet) | 1,500 | 18,000 |
| Insurance (health, home, car) | 800 | 9,600 |
| Discretionary (eating out, hobbies, travel) | 3,000 | 36,000 |
| Subscriptions and memberships | 500 | 6,000 |
| Clothing and personal care | 800 | 9,600 |
| Subtotal | 20,600 | 247,200 |
| 10% buffer for unexpected costs | 2,060 | 24,720 |
| Total | 22,660 | 271,920 |
FIRE Number for this example: DKK 271,920 × 25 = DKK 6,798,000
Add a 10% buffer to your expenses to account for medical emergencies, home repairs, travel, or inflation spikes. This is not optional — it is a necessary safety margin.
4% Rule: The Safe Withdrawal Rate
The 4% rule works as follows:
- Year 1: withdraw 4% of your portfolio
- Each subsequent year: adjust the withdrawal amount for inflation
- Example: DKK 7.5M portfolio → DKK 300,000 in year one → DKK 306,000 in year two (2% inflation)
The rule has a 95%+ success rate over 30-year periods based on historical US data. For Denmark, adjust conservatively to 3.5% due to higher taxes on investment returns and a smaller domestic market.
At 3.5% SWR: DKK 300,000 annual expenses require DKK 8,571,429 (÷0.035 instead of ×25).
Danish-Specific Considerations
High Tax Rates
Denmark’s marginal income tax rate reaches 52.5% (state + municipal). Investment income is taxed at:
- 27% on the first DKK 61,000 of gains (2026 threshold)
- 42% on gains above that threshold
- Dividends face the same rates
- There is no capital gains exemption on shares
This means your gross returns are significantly reduced. A 7% nominal return becomes roughly 4.9% after 42% tax on gains.
Limited Tax-Advantaged Accounts
Unlike the US (401k, IRA, Roth IRA), Denmark offers limited tax wrappers:
- Aktiesparekonto: taxed at a flat 17% on gains, but contribution limit is only DKK 136,200
- Ratepension: tax-deductible contributions, taxed at withdrawal (locked until age 60+)
- Aldersopsparing: taxed at 15.4% at withdrawal, limited to DKK 59,200/year
- No ISA equivalent: no tax-free wrapper beyond aktiesparekonto
- No capital gains allowance: every krone of gain is taxable
Your FIRE portfolio must be largely held in taxable accounts, making tax efficiency critical.
Pension Is Locked
Danish pension contributions are locked until age 60+ (ratepension and aldersopsparing). You cannot use pension money for early retirement. Your FIRE number must come from non-pension investments.
Timeline Calculation: When Will You Reach FIRE?
Use the compound interest formula to estimate your timeline:
FV = PV × (1 + r)^n + PMT × ((1 + r)^n - 1) / r
Where:
- FV = target FIRE number
- PV = current portfolio value
- r = expected annual return (after tax)
- n = number of years
- PMT = annual contribution (savings invested each year)
Example
- Current savings: DKK 500,000
- Monthly investment: DKK 20,000 (annual: DKK 240,000)
- Expected return: 7% nominal, ~5% after tax
- FIRE number: DKK 7,500,000
At 5% after-tax return, saving DKK 20,000/month with DKK 500,000 starting balance:
| Year | Portfolio Value |
|---|---|
| 0 | DKK 500,000 |
| 5 | DKK 1,973,000 |
| 10 | DKK 3,768,000 |
| 15 | DKK 5,934,000 |
| 18 | DKK 7,500,000 |
You reach DKK 7.5M in approximately 18 years.
Savings Rate Impact
Your savings rate — the percentage of your income you save — is the single biggest factor in your FIRE timeline. Higher savings rates compress the timeline dramatically.
| Savings Rate | Years to FIRE (from zero) | Annual Expenses Assumed |
|---|---|---|
| 20% | ~37 years | DKK 300,000 |
| 30% | ~28 years | DKK 300,000 |
| 40% | ~22 years | DKK 300,000 |
| 50% | ~17 years | DKK 300,000 |
| 60% | ~12.5 years | DKK 300,000 |
| 70% | ~8.5 years | DKK 300,000 |
The relationship is non-linear. Going from 20% to 30% saves 9 years. Going from 60% to 70% saves only 4 years but starts from a much higher baseline.
Lean FIRE vs Fat FIRE
Lean FIRE
Annual expenses: DKK 200,000 or less (DKK 5M portfolio needed)
Lean FIRE means minimal spending — small apartment, limited travel, cooking at home, no car. It works for people with low lifestyle expectations or in low-cost areas of Denmark (rural Jutland, smaller towns).
Fat FIRE
Annual expenses: DKK 600,000+ (DKK 15M+ portfolio needed)
Fat FIRE maintains a comfortable lifestyle — larger home, regular travel, dining out, hobbies, generous gifting. This requires significantly more capital and a longer accumulation phase.
Barista FIRE
Part-time work covers some or all expenses, reducing the portfolio drawdown needed. You might work 15-20 hours per week at a low-stress job while your portfolio covers the gap. This extends your portfolio longevity and reduces sequence-of-returns risk.
Withdrawal Strategy: Tax-Optimized Drawdown
When withdrawing from your FIRE portfolio, order matters for tax efficiency:
- Aldersopsparing first — lowest tax rate (15.4%), withdraw as early as allowed (age 60+)
- Ratepension second — taxed at your marginal rate, but only available after age 60
- Regular taxable account — capital gains tax at 27%/42%, but available immediately
- Aktiesparekonto — 17% tax on gains, no withdrawal restrictions
For early retirees (before 60), you rely almost entirely on your taxable account. This means managing withdrawals to stay within the 27% tax bracket each year (below DKK 61,000 in gains per person, or DKK 122,000 for a couple).
Practical Example
A couple with DKK 7.5M in a taxable account can withdraw DKK 122,000 per year at 27% tax. For expenses above that, they draw from the aktiesparekonto or accept the 42% rate on excess gains.
Worked Example: Full FIRE Calculation
Profile: 30-year-old earning DKK 50,000/month gross
| Item | Amount |
|---|---|
| Monthly income (after tax) | DKK 32,500 |
| Monthly expenses | DKK 12,500 |
| Monthly savings | DKK 20,000 |
| Savings rate | 40% |
| Current portfolio | DKK 500,000 |
| Annual return (nominal) | 7% |
| After-tax return | ~5% |
| FIRE number | DKK 7,500,000 |
Timeline:
- Age 30: DKK 500,000
- Age 35: DKK 2,200,000
- Age 40: DKK 4,100,000
- Age 45: DKK 6,300,000
- Age 48: DKK 7,500,000 — FIRE achieved
- Age 50: DKK 10,000,000 (if continuing to work)
At age 48, this person can sustain DKK 300,000 annual expenses indefinitely at a 4% withdrawal rate. If they work two more years to age 50, they reach DKK 10M, enabling DKK 400,000/year (fat FIRE territory).
Tools and Calculators
- Compound interest calculator: compoundinterestcalculator.net — model your portfolio growth over time
- FIRE calculator: firecalc.com — test different withdrawal rates against historical data
- Danish tax calculator: skat.dk — verify your actual after-tax return
- Portfolio tracker: Nordnet app, Sharesight, or a custom Excel spreadsheet
- Spreadsheet model: build your own in Google Sheets using the
FV()function:=FV(rate, nper, pmt, pv)where rate is monthly return, nper is months, pmt is monthly contribution, pv is starting balance
Tips for Danish Investors
- Track every expense for 1 month. You cannot calculate your FIRE number without knowing your real spending. Use a spreadsheet or app like Spiir.
- Calculate your FIRE number today. Write it down. It becomes your target.
- Set up automatic monthly investments. Nordnet’s auto-invest feature removes decision fatigue. Invest on the same day each month.
- Increase your savings rate annually. When you get a raise, invest the difference before lifestyle creep sets in.
- Don’t forget your pension. Danish pension is locked until 60+, but it is part of your total retirement income. Track it separately from your FIRE portfolio.
- Rebalance yearly. Review your asset allocation once per year. Sell winners to maintain your target allocation.
- Adjust for inflation. Update your FIRE number annually using 2-3% inflation. DKK 7.5M today is DKK 9.8M in 10 years at 2.5% inflation.
- Stress-test your number. Model a 30% market crash in year one of retirement (sequence-of-returns risk). Can you still survive?
Your FIRE number is not a fantasy — it is a calculation. Do the maths, set the target, and let compound interest do the heavy lifting over the next 15-25 years.