About SimpleFIRE

SimpleFIRE is a one-person project. I built it because the FIRE calculators I could find online were either buried in jargon, locked behind a sign-up wall, or made assumptions about currency and terminology that didn't match how I actually think about money. This is my attempt at the calculator I wished existed — free, no account required, and explained the way you'd explain it to a friend.

Why SimpleFIRE is different

Most FIRE calculators assume you already know what "SWR" or "coast" or "the 4% rule" means. SimpleFIRE doesn't — every input is labeled in plain English, and where a term is genuinely useful to understand (like withdrawal rate, or inflation), there's a small ⓘ next to it explaining what it means and why it matters, right where you need it. No currency is hardcoded either — type a number at whatever scale makes sense for you, whether that's thousands or millions.

It's also just simpler to use: one page, sliders you can drag, a chart you can hover over. No account, no email capture, no upsell.

This is a passion project

I'm not a financial advisor, and SimpleFIRE isn't a company — it's something I built and maintain myself, on my own time, because I find this stuff genuinely interesting. If it's useful to you, that's the whole point.

Found a bug?

If something looks wrong — a calculation that doesn't add up, a chart that's misbehaving, anything at all — I'd genuinely like to know. Contact details are coming soon; check back here.

Disclaimer

SimpleFIRE is provided for educational and illustrative purposes only. It is not financial, investment, tax, or legal advice, and nothing on this site should be treated as a recommendation to buy, sell, or hold any investment, or as a substitute for professional advice tailored to your circumstances.

All figures are estimates based on the assumptions you enter — growth rate, inflation, withdrawal rate, and so on — and on a simplified model of how markets behave. Real markets don't move in a straight line: some years lose money, others return 20%+, and a bad sequence of returns early in retirement can matter far more than the same bad years spread out elsewhere, even with an identical long-run average. Past performance is never a guarantee of future results.

Tax treatment in particular varies enormously by country and by individual circumstances, and the numbers this calculator shows should not be relied on for actual tax planning. Before making any financial decision, talk to a qualified, licensed professional who knows your full situation.