About My FIRE Calculators
Clear, honest FIRE calculators, with the math shown, not hidden. We built My FIRE Calculators because the tools we found were either buried in ads or hard to trust.
Who's behind this
My FIRE Calculators is built and maintained by Muhammad Tayyab Shabbir, founder of Avvale, a London business-planning firm. Since 2021 he has written business plans and built financial models for 500+ founders across the US, UK and UAE, the day job is making financial projections that investors and banks will actually scrutinize. Before that: an MSci in Theoretical & Mathematical Physics from UCL (2017–2021), which is where the habit of showing your working comes from.
Why this site exists
After years of building compound-growth models professionally, the state of free FIRE calculators was frustrating: most either hide their assumptions, bury the tool under ads, or quietly use math that doesn't survive scrutiny. This site is the opposite bet, every formula printed on the page, every assumption adjustable, everything computed in your browser. If you can check the math, you can trust the number; if you can't, you shouldn't.
To be clear about what this isn't: Muhammad is a financial modeller, not a licensed financial adviser, and nothing on this site is personal financial advice. Connect on LinkedIn.
What we do
My FIRE Calculators makes free, fast calculators for the FIRE (Financial Independence, Retire Early) community, Coast FIRE, Barista FIRE, Lean FIRE and your full FIRE number. Every calculator updates live, works in five currencies, and shows exactly how it reached your result. No sign-up, no clutter.
Our methodology
We keep the math transparent and conventional so you can trust and check it:
- FIRE number = annual spending ÷ safe withdrawal rate (default 4%, the Trinity Study standard).
- Coast FIRE number = FIRE number ÷ (1 + real return)years to retirement.
- Real return = your expected investment return − inflation − fees, so every figure is in today's dollars.
- Projections compound your current investments plus monthly contributions forward month by month.
Defaults (7% return, 3% inflation, 4% withdrawal) are deliberately middle-of-the-road; you can change every assumption under "Advanced assumptions."
Our promise
- The calculators are free and always will be.
- We show the formula behind every number.
- We never sell your data. The calculators run entirely in your browser, your inputs never leave your device.
Why the assumptions default the way they do
Every default is a deliberate choice, not a leftover:
- 7% nominal return reflects a broadly diversified stock portfolio over long horizons, without promising the best decades will repeat. Paired with 3% inflation it gives roughly a 4% real return, on the cautious side of historical averages.
- 4% withdrawal rate is the Trinity Study benchmark for a ~30-year retirement. Retiring very early? The calculators let you set 3–3.5% instead, and our 4% rule calculator shows how much the choice matters.
- 0% fees assumes low-cost index funds. If you pay platform or fund fees, enter them, over decades even 0.5% compounds into years of extra work.
When a page shows a table (like Coast FIRE by age), the same engine generates it from your live inputs, so the table and the chart never disagree.
What we don't do
- We don't model taxes. Account types and jurisdictions vary too much to fake precision, treat taxes as part of your annual spending.
- We don't predict markets. Projections are smooth curves; real returns arrive in lumps. Use conservative assumptions and re-run yearly.
- We don't give personal advice. The tools show arithmetic; what you do with it is between you and, ideally, a qualified fee-only professional.
Get in touch
Spotted a bug or have an idea for a calculator? We'd genuinely like to hear it. Email [email protected] or use the contact page.
My FIRE Calculators is published by Avvale Ltd, a company registered in England and Wales, company number 14805382. Editorial contact: [email protected].