Play with the numbers.
The FIRE calculator and growth projection, right here in your browser. Move the sliders and watch the curves respond — simplified versions of the tools inside Finzya, no sign-up required.
What is a FIRE number?
Your FIRE number is the portfolio size at which work becomes optional: the point where a sustainable withdrawal — commonly 4% a year — covers your annual spending. Multiply your yearly expenses by 25 and you have a first estimate. The calculator shows how the pieces interact: spend less and the target drops quickly, contribute more and you reach it sooner, change the withdrawal rate and the whole line shifts. Knowing the number is what turns “retire someday” into a date you can plan around.
Why project growth at all?
Because compounding is easy to underestimate. Save £800 a month for 20 years and you will have contributed £192,000 — but at 7% annual growth the portfolio ends up around £420,000. A projection turns that abstract promise into a curve you can see, and it makes the trade-offs concrete: saving more, starting earlier, or taking more risk each bend the line in a different way. None of it is a prediction — it is a way to compare your options before you commit to one.
The full app includes per-account tracking, custom scenarios, historical data, and currency-specific formatting.
See where your money
is taking you.
Start building a complete picture of your financial life — where you stand today, and the future you're working toward. Free to start, set up in an afternoon.