FIRE Calculator
Estimate your FIRE number, years to financial independence, and required annual contribution from expenses, savings, return, and withdrawal rate.
FIRE Details
Enter your savings and retirement goals.
The 4% rule is the most widely used benchmark.
FIRE Projection
Years to Financial Independence
25 yrs
You will reach your FIRE number of GBP GBP 1.00M at age 55.
FIRE Number
GBP 1,000,000.00
Retirement Age
Age 55
Year-by-Year Projection
| Year | Age | Starting | Growth | Contribution | Ending Balance |
|---|---|---|---|---|---|
| 1 | 31 | GBP 50,000.00 | +GBP 3,500.00 | +GBP 12,000.00 | GBP 65,500.00 |
| 2 | 32 | GBP 65,500.00 | +GBP 4,585.00 | +GBP 12,000.00 | GBP 82,085.00 |
| 3 | 33 | GBP 82,085.00 | +GBP 5,745.95 | +GBP 12,000.00 | GBP 99,830.95 |
| 4 | 34 | GBP 99,830.95 | +GBP 6,988.17 | +GBP 12,000.00 | GBP 118,819.12 |
| 5 | 35 | GBP 118,819.12 | +GBP 8,317.34 | +GBP 12,000.00 | GBP 139,136.45 |
| 6 | 36 | GBP 139,136.45 | +GBP 9,739.55 | +GBP 12,000.00 | GBP 160,876.01 |
| 7 | 37 | GBP 160,876.01 | +GBP 11,261.32 | +GBP 12,000.00 | GBP 184,137.33 |
| 8 | 38 | GBP 184,137.33 | +GBP 12,889.61 | +GBP 12,000.00 | GBP 209,026.94 |
| 9 | 39 | GBP 209,026.94 | +GBP 14,631.89 | +GBP 12,000.00 | GBP 235,658.83 |
| 10 | 40 | GBP 235,658.83 | +GBP 16,496.12 | +GBP 12,000.00 | GBP 264,154.94 |
| 11 | 41 | GBP 264,154.94 | +GBP 18,490.85 | +GBP 12,000.00 | GBP 294,645.79 |
| 12 | 42 | GBP 294,645.79 | +GBP 20,625.21 | +GBP 12,000.00 | GBP 327,270.99 |
| 13 | 43 | GBP 327,270.99 | +GBP 22,908.97 | +GBP 12,000.00 | GBP 362,179.96 |
| 14 | 44 | GBP 362,179.96 | +GBP 25,352.60 | +GBP 12,000.00 | GBP 399,532.56 |
| 15 | 45 | GBP 399,532.56 | +GBP 27,967.28 | +GBP 12,000.00 | GBP 439,499.84 |
| 16 | 46 | GBP 439,499.84 | +GBP 30,764.99 | +GBP 12,000.00 | GBP 482,264.83 |
| 17 | 47 | GBP 482,264.83 | +GBP 33,758.54 | +GBP 12,000.00 | GBP 528,023.37 |
| 18 | 48 | GBP 528,023.37 | +GBP 36,961.64 | +GBP 12,000.00 | GBP 576,985.00 |
| 19 | 49 | GBP 576,985.00 | +GBP 40,388.95 | +GBP 12,000.00 | GBP 629,373.95 |
| 20 | 50 | GBP 629,373.95 | +GBP 44,056.18 | +GBP 12,000.00 | GBP 685,430.13 |
| 21 | 51 | GBP 685,430.13 | +GBP 47,980.11 | +GBP 12,000.00 | GBP 745,410.24 |
| 22 | 52 | GBP 745,410.24 | +GBP 52,178.72 | +GBP 12,000.00 | GBP 809,588.96 |
| 23 | 53 | GBP 809,588.96 | +GBP 56,671.23 | +GBP 12,000.00 | GBP 878,260.18 |
| 24 | 54 | GBP 878,260.18 | +GBP 61,478.21 | +GBP 12,000.00 | GBP 951,738.40 |
| 25 | 55 | GBP 951,738.40 | +GBP 66,621.69 | +GBP 12,000.00 | GBP 1,030,360.08 |
Disclaimer: Results are estimates based on constant assumptions. Actual investment returns vary. Not financial advice.
About This FIRE Calculator
Financial Independence, Retire Early (FIRE) planning starts with a target portfolio size, often called a FIRE number. This calculator estimates that number from your expected annual expenses and chosen withdrawal rate.
It can also estimate how many years it may take to reach that target from your current savings, annual contribution, and expected annual return. The Contribution tab works backwards from a target age or target FIRE number to estimate the annual contribution needed.
This is a simplified projection, not a full retirement plan. The calculator helps with the core FIRE maths, but tax, pension rules, social security, sequence-of-returns risk, healthcare costs, inflation, and country-specific retirement rules still need separate planning.
FIRE Number Example
If you expect to spend GBP 32,000 per year in retirement and use a 4% withdrawal rate, your FIRE number is GBP 800,000. At a more conservative 3.5% withdrawal rate, the target rises to about GBP 914,286.
That target is sensitive to lifestyle. Reducing annual expenses by GBP 4,000 can lower the required portfolio by GBP 100,000 under the 4% rule.
Why Savings Rate Matters Most
FIRE timelines are driven by the gap between income and spending. A higher savings rate both increases contributions and reduces the future portfolio needed to support your lifestyle.
Investment returns matter, but they are uncertain. Spending, contribution rate, and retirement flexibility are usually more controllable than market performance.
How to Make a FIRE Plan More Realistic
Use conservative returns, test lower withdrawal rates, and keep a margin for healthcare, housing repairs, tax changes, inflation, and family needs. A plan that only works under perfect assumptions is fragile.
Many people use Coast FIRE, Barista FIRE, or part-time work as intermediate goals. These options can reduce pressure while still moving toward financial independence.
Reading the result with real-world context
The FIRE number is calculated from annual expenses divided by withdrawal rate. Lower expenses or a lower withdrawal rate can change the target dramatically.
The timeline estimate assumes the same annual contribution and expected return each year. Real markets move unevenly, so sequence-of-returns risk still needs separate thought.
The contribution mode works backwards from a target age or FIRE number to estimate the annual saving needed.
Taxes, pensions, social security, healthcare, inflation, and country-specific rules are outside this calculator, so keep a separate margin for them.
Common mistakes to avoid
Using a withdrawal rate that is too optimistic for a very long retirement.
Entering a nominal investment return while also treating future expenses as today's spending power.
Ignoring tax, pension access rules, healthcare costs, housing changes, or family needs because they are not fields in this calculator.
How to combine this with related calculators
Use retirement savings when the goal is traditional retirement saving rather than an early-retirement FIRE target.
Use savings for shorter-term cash goals that should not depend on investment returns.
Use inflation adjusted return when you want to compare nominal returns with purchasing-power outcomes.
When to revisit the numbers
Rerun the plan when annual expenses, contributions, expected return, or withdrawal rate changes.
Review after major life changes such as housing moves, dependents, health needs, tax changes, or income shifts.
Keep the assumptions visible so you can tell whether progress changed because of saving behaviour, market returns, or a changed target.
How to Use This Calculator
- 1
Enter your current financial position
Start with your current age and total amount already saved or invested. This is the starting point for your FIRE projection.
- 2
Set your annual contribution
Enter how much you plan to invest each year going forward. This is the single biggest lever you control - increasing contributions shortens your timeline significantly.
- 3
Enter your expected return and expenses
Set your expected annual investment return and your expected annual spending in retirement. Spending and withdrawal rate determine your FIRE number.
- 4
Review your timeline and year-by-year table
The calculator shows how many years it may take to reach your FIRE number and the estimated age that implies. The year-by-year table shows your projected portfolio balance for each year along the way.
Frequently Asked Questions
What is the FIRE number?
Your FIRE number is the target portfolio size implied by your expected annual expenses and chosen withdrawal rate. It is calculated by dividing annual expenses by withdrawal rate. At a 4% withdrawal rate, the simple target is 25 times annual expenses.
What is the 4% rule?
The 4% rule is a retirement planning benchmark based on withdrawing 4% of a portfolio in the first year, then adjusting withdrawals over time. It is a starting assumption, not a guarantee, and early retirement often needs more cautious testing.
Is a 4% safe withdrawal rate safe for early retirement?
Many early retirees use a more conservative rate of 3% or 3.5% to account for a longer retirement horizon (40-60 years instead of 30). The 4% rule was originally designed for traditional retirement ages. Adjust the safe withdrawal rate field to model different scenarios.
What annual return rate should I use?
Use an assumption that matches the type of return you want to model. A nominal return includes inflation; a real return is already inflation-adjusted. The calculator does not add inflation separately, so keep your expenses and return assumption consistent.
What does the Contribution tab do?
The Contribution tab works backwards: enter your target retirement age and FIRE number, and the calculator estimates how much you need to save each year to hit your goal. This is useful for setting a savings target.
What is the difference between FIRE, LeanFIRE, and FatFIRE?
FIRE (Financial Independence, Retire Early) is the general concept. LeanFIRE targets a frugal retirement with lower annual expenses (often under GBP 25,000/year). FatFIRE targets a comfortable or luxurious retirement with higher annual spending. Adjust the annual expenses field to model any of these variants.
Is the FIRE Calculator financial advice?
No. It is a general planning estimate based on the values you enter. Confirm important borrowing, investing, tax, or property decisions with qualified professionals and official terms from lenders or providers.
How often should I update my inputs?
Update when rates, income, prices, rent, contributions, or goals change materially. For most household finance decisions, reviewing every few months or after a major change is enough.
Why might this differ from a full retirement plan?
A full retirement plan may include tax, pensions, inflation, healthcare, withdrawal sequencing, and local rules. This calculator keeps the FIRE number, timeline, and contribution estimate deliberately simple.