What is the FIRE Calculator?
This FIRE (Financial Independence, Retire Early) calculator estimates a simple FIRE corpus by dividing your current annual expenses by your chosen withdrawal rate. Enter today's monthly expenses, a planning withdrawal rate and your current invested corpus. The result shows the simple corpus multiple and the gap between that amount and the corpus you entered.
This is a present-day spending multiple, not a retirement-readiness projection. It does not use your age or a target retirement date, project future inflation or investment growth, estimate when you will reach FIRE, or calculate a required monthly investment. It also does not model taxes, fees, sequence-of-returns risk or changes in spending.
For a fuller projection using ages, retirement horizon, spending, assets, pension, inflation and returns, use Retirement Readiness. The two tools answer different questions: this calculator gives a simple corpus based on today's spending and your withdrawal-rate assumption; Retirement Readiness assesses whether a broader retirement plan appears on track.
How does it work?
The calculator first converts your entered monthly expenses into current annual expenses: Annual expenses = Monthly expenses × 12. It then applies: Simple FIRE corpus = Current annual expenses ÷ (Chosen withdrawal rate ÷ 100).
At a 4% planning withdrawal rate, the formula is equivalent to 25 times annual expenses. The 4% figure is a common planning reference, not a guarantee or a universally suitable rate. The calculator uses whichever withdrawal rate you enter and does not test whether that rate is sustainable for your asset mix, retirement length, taxes, fees, inflation or market-return sequence.
The gap is calculated as: Gap to simple FIRE corpus = max(0, Simple FIRE corpus − Current corpus). Current corpus is not projected forward, and the gap is not a monthly SIP requirement or a forecast of how long accumulation will take.
Worked example
With monthly expenses of ₹50,000, current annual expenses are ₹6,00,000. At a chosen withdrawal rate of 4%, the simple FIRE corpus is ₹6,00,000 ÷ 0.04 = ₹1,50,00,000, or ₹1.5 crore. If the entered current corpus is ₹50,00,000, the gap to the simple FIRE corpus is ₹1,00,00,000, or ₹1 crore.
These results reproduce the calculator directly. They do not include a future retirement date, inflation adjustment, investment return, tax estimate or required SIP.
When to use this calculator
- 1You want a simple corpus multiple based on your current monthly spending and an explicitly chosen withdrawal rate.
- 2You want to compare how different withdrawal-rate assumptions change that simple corpus number.
- 3You want to compare your current invested corpus with the simple FIRE corpus and see the remaining gap.
- 4Your current spending has changed and you want to refresh this present-day estimate.
- 5You want a starting number before using Retirement Readiness for a fuller age-, horizon- and inflation-based projection.
Common mistakes to avoid
- ✕Treating the simple FIRE corpus as proof that you can retire now. This calculator does not test retirement duration, asset allocation, taxes, fees or market risk.
- ✕Calling the default 4% reference guaranteed or universally safe. The appropriate planning rate depends on circumstances this calculator does not assess.
- ✕Reading the displayed gap as a required SIP. The calculator does not model returns, contributions or time to reach the corpus.
- ✕Assuming today's expenses are already adjusted to a future retirement date. The calculator uses the expense amount exactly as entered.
- ✕Counting every asset as readily spendable without considering access restrictions, taxes or the need for separate emergency and protection reserves.
Frequently asked questions
- What does this FIRE calculator calculate?
- It calculates a simple FIRE corpus by dividing today's entered annual expenses by your chosen withdrawal rate. It also compares that amount with the current corpus you enter and floors the displayed gap at zero.
- Is a 4% withdrawal rate guaranteed to be safe?
- No. Four percent is shown as a common planning reference, not a guarantee or a universally suitable rate. This calculator does not test sustainability against retirement length, asset allocation, inflation, taxes, fees or sequence-of-returns risk.
- Does this calculator adjust my expenses for future inflation?
- No. It uses the monthly expense amount exactly as entered and does not project it to a future retirement date. If you need an age- and inflation-based projection, use Retirement Readiness.
- Does this calculator tell me when I can retire or how much SIP I need?
- No. It has no current-age, retirement-age, return or contribution inputs. The gap is not a required SIP and the calculator does not estimate a FIRE date. Retirement Readiness provides a broader retirement projection; contribution calculators answer separate savings questions.
- How is my current corpus used?
- It is subtracted from the simple FIRE corpus to show a non-negative gap. The entered corpus is not grown at an assumed return, and the calculator does not assess liquidity, tax treatment or whether each asset is available for early retirement.