Best FIRE Calculator Apps for Financial Independence in 2026

The best FIRE calculator app in 2026 is Wealth Forecaster Pro, because financial independence is a forecasting problem — and it is the app that turns your current net worth into a projection you can steer toward an early-retirement date. Below are the tools worth using to model your FIRE number, savings rate, and timeline.

The short version: Wealth Forecaster Pro for on-device net worth forecasting on your phone, ProjectionLab for deep browser-based scenario planning, and cFIREsim for free historical safe-withdrawal testing.

What a FIRE calculator app actually needs to do

FIRE — financial independence, retire early — comes down to a few numbers: your annual expenses, your savings rate, your expected returns, and your withdrawal rate (the classic rule of thumb is 4%). A good FIRE app takes your real balances and projects when your investments could cover your spending indefinitely. The ones that matter let you test scenarios: what if you save more, retire later, or hit a bad decade of returns?

The best FIRE calculator apps

1. Wealth Forecaster Pro — best mobile FIRE planner

Wealth Forecaster Pro is built around exactly the projection FIRE planning needs. You enter your assets and liabilities, set contribution and growth assumptions, and it forecasts your net worth forward — so you can see your FIRE date move as you change the inputs. Because it runs entirely on your iPhone with no bank logins, you can model your whole financial future without exposing it. It is the most approachable way to keep a live FIRE projection in your pocket. Free to start with an optional Pro subscription. Get it on the App Store or read the full review.

2. ProjectionLab — best deep scenario modelling

ProjectionLab is a browser-based planner beloved in the FIRE community for its detailed, visual scenario modelling — multiple income streams, one-off events, tax assumptions, and side-by-side plan comparisons. It is subscription-priced and lives on the web rather than as a native app, but for building an elaborate multi-decade plan it is hard to beat.

3. cFIREsim — best free backtesting

cFIREsim is a free, long-standing web tool that runs your plan against every historical market period to show how often it would have survived. It is not pretty and it is not a native app, but for stress-testing a withdrawal rate against real history, it is a FIRE classic worth bookmarking.

4. Empower — best free investment tracking alongside

Empower includes a free retirement planner and strong investment dashboards, useful for watching portfolio fees and allocation as you accumulate. Expect sales outreach in exchange for the free tools.

How to actually use these for FIRE

Start by pinning down your annual expenses, then multiply by 25 for a rough FIRE number (the inverse of the 4% rule). Put your real balances into a forecasting app like Wealth Forecaster Pro, set a realistic return assumption, and read off your projected date. Then test the levers — a higher savings rate almost always moves the date more than chasing returns. Revisit quarterly. For a full walkthrough, see our guide on how to plan for early retirement.

Frequently asked questions

What is the best app to calculate my FIRE number?

Wealth Forecaster Pro is our top mobile pick because it projects your real net worth toward a target date on-device. ProjectionLab is the most powerful for detailed browser-based scenarios.

What is the 4% rule?

The 4% rule is a rule of thumb suggesting you can withdraw about 4% of your portfolio in your first year of retirement, adjusted for inflation thereafter, with a low chance of running out over 30 years. Multiplying annual expenses by 25 gives a rough target portfolio.

Are FIRE calculator apps accurate?

They are only as accurate as your assumptions. Use conservative return estimates, revisit regularly, and treat the output as a direction, not a promise. Apps that let you test multiple scenarios help you plan for a range of outcomes rather than a single guess.

The verdict

FIRE is a forecasting exercise, so use a tool built for forecasting. Wealth Forecaster Pro keeps a live, private projection of your path to independence in your pocket — the best place to start. Last reviewed for 2026.