Coastful: Coast FIRE & Retire

ZW Studio LLC

In-app purchases

About this app

Coastful is the Coast FIRE and retirement calculator built around YOUR portfolio. Project the year you can retire from real expenses, your real allocation, and the assumptions YOU choose. Whether you're planning Coast FIRE, Lean FIRE, or Fat FIRE, the math runs on your actual asset mix — not a textbook 4% rule.

★ COAST FIRE SIMULATION
Find the year you can stop contributing — and let compounding finish the job on time.

★ PERSONALIZED SAFE WITHDRAWAL RATE
A real-return SWR built from your actual asset mix, not a generic 4%. A mix that includes some lower-return holdings yields a more conservative SWR — and a more honest FIRE number.

★ INFLATION, MODELED
Every future dollar in your projection is discounted by inflation. The chart you see is real-dollar, not nominal. Tunable to match your view of the next decade.

★ WHAT-IF SCENARIOS
Three built-in scenarios show how a change today moves your FIRE year:
• Save more per month → years pulled forward
• Market drop pre- or post-FIRE → years delayed
• Upgrade or downgrade your home → years shifted

★ THE FREE CALCULATOR
• Your FIRE number from real annual expenses (classic 4% rule / 25× target).
• Funded percentage that updates as your portfolio grows.
• Multi-decade projection chart with the year your portfolio crosses the target.
• Net worth dashboard with year-over-year history and allocation by category.
• Unlimited assets and snapshots.
• Quick-update value with a one-tap pencil; batch-update at month-end.
• On-device backup and restore.
• Biometric app lock.

★ PRIVACY BY DESIGN
• 100% on-device. No backend, no cloud sync, no account.
• No bank logins — you enter your own values.
• No analytics, no ad SDKs, no third-party trackers.
• Optional biometric lock on every launch.
• Exports and imports stay on your device.

What’s new

Welcome to Coastful — a private, on-device FIRE & Coast FIRE
calculator built around your actual portfolio.

• Net worth dashboard with allocation breakdown
• FIRE & Coast FIRE projections from your real assets
• What-if scenarios for spending, savings, and returns
• 100% on-device — no account, no cloud sync
• Optional biometric lock