Calculators
Free FIRE & money calculators
Quick, honest tools for planning financial independence, no sign-up and nothing stored. Everything runs in real terms, so the answers are in today's money.
FIRE Calculator
The age you could retire and the FIRE number you need, from what you've saved and what you invest each month.
Open calculator →Coast FIRE Calculator
Your Coast number, the pot that grows into your full number on its own, and whether you're already there.
Open calculator →Barista FIRE Calculator
How much part-time income lets you semi-retire early, and the smaller pot you'd need to make it work.
Open calculator →Compound Interest Calculator
Watch a starting sum and monthly contributions grow over time, and see how much of the end is pure compounding.
Open calculator →Mortgage Calculator
Monthly payment, total interest, and how much sooner extra payments clear the loan.
Open calculator →Savings Rate Calculator
The single number that most decides how soon you retire: the share of your take-home pay you keep.
Open calculator →Why free calculators, from an app maker?
These tools give you the universal version of the math for free, in your browser, with nothing stored. They're the honest first pass. What they can't see is the part that actually decides your date: tax, pensions, and the account rules of where you live, which differ by country and can move a real retirement age by years.
That's the job of Runway, the app. It takes the same ideas, applies your country's real rules to your own figures, runs your plan through 400 market futures, and shows the levers that pull your date sooner, even retiring abroad. The calculators are the doorway; the app is the full plan. New reading meanwhile lives on the blog.
Your freedom age, free forever
Runway turns your money into one honest number: the age you could stop working, by your country's real rules. It launches on the App Store on 25 August 2026, and the beta is open now.
Runway turns your money into one honest number: the age you could stop working, by your country's real rules. Free on the App Store, no account needed.
Try the beta on TestFlight Download free on the App Store