Hitting your FIRE number is easy.
Staying retired is the hard part.

Ember is a private, client-side FIRE planner that shows not just when you can retire β€” but whether your money actually lasts. Monte-Carlo and historical simulations, life events, guardrail spending. Free to start. No sign-up.

Build your plan β€” free β†’  Try the Coast FIRE calc
πŸ”’ The free planner runs 100% in your browser🌍 6 display currenciesπŸ“± Works on mobile⚑ No sign-up
Hitting a 25Γ— "FIRE number" and then retiring can still fail more often than you'd think:
~44%
chance your money lasts in one illustrative scenario (retiring the moment you hit 25Γ—, 4% withdrawals, returns barely above them β€” full assumptions in the methodology). Ember shows you this β€” and how guardrail spending lifts the same scenario toward ~90%. Most free calculators never tell you.

What makes Ember different

The depth of a power tool, the speed of a free calculator β€” and the free planner never sends your numbers anywhere.

🎲

Will it actually last?

Monte-Carlo plus an illustrative sequence stress test give a success probability and a safe retirement age β€” not just a single number.

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Private by design

The free planner computes everything in your browser β€” nothing is uploaded. The optional account (beta) syncs your plan encrypted in transit and at rest.

🏑

Model real life

Home, kids, a car, a career break, a windfall, other income β€” see each ripple through your plan.

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Smarter spending

Guyton-Klinger guardrails flex your spending with the market and can turn a risky plan into a robust one.

🌍

Global & mobile

Six currencies, great on your phone, instant β€” no account, no wall between you and your answer.

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Fair price

Free covers your number & timeline. Pro is $79/yr β€” well under the $129–144 incumbents.

Pricing

Start free. Pro purchasing isn't open yet β€” these are the launch prices, published early for honesty.

Free

$0

no sign-up

  • Your FIRE number & timeline
  • Coast/Lean/Fat targets
  • 6 currencies
  • Deterministic projection
Open the app

Pro

$79/yr

or $9/mo Β· at launch

  • Monte-Carlo success probability
  • Sequence stress test (illustrative)
  • Drawdown & longevity
  • Life events, A/B compare, sensitivity
  • Export (.ember / CSV) Β· account sync in beta
Start free today

Free tools

Instant single-purpose calculators β€” no sign-up.

πŸ”₯ Ember β€” see the day work becomes optional. The free planner computes in your browser. Not financial advice.
How it calculates Β· Home Β· Full planner
Β© Mathom Studio Β· β€œEmber” is a working name (trademark pending) Β· privacy & terms pages ship with the beta