Find your FI date and Coast FI age in one shot

Feed in your current age, invested assets, monthly savings, and target retirement spend — get a complete FIRE projection dashboard with Coast FI, three scenarios, and 1000-trial Monte Carlo.

$9.99

Works in Claude (Pro/Max/Team) or ChatGPT (Plus/Team) · paid AI plan required

Both Claude + ChatGPT packages included — you can't pick the wrong one.

Updated May 26, 2026

Included

01Calculates your projected FI age AND your Coast FI age — the number most FIRE calculators skip entirely

02Models lean FIRE ($40k), regular FIRE, and fat FIRE ($100k+) side-by-side with FI number, years, and target age each

03Runs 1000-trial Monte Carlo at 7% mean / 15% SD so you see success probability and 10th/50th/90th percentile outcomes

04Outputs a self-contained HTML dashboard, CSV year-by-year projection, and a paste-ready Google Sheets formula block

05Honors the FIRE vocabulary — 4% rule, Trinity Study, Bengen, ERN, CAPE-adjusted SWR, Guyton-Klinger guardrails, bond tent

06Handles follow-ups instantly: 5% real return, Barista FIRE bridges, lump-sum windfalls, later FI dates, sequence-risk scenarios

What it does

Most FIRE calculators give you one number and call it a day. This skill builds the full picture: your projected FI age under lean, regular, and fat FIRE spending targets, your Coast FI age (the point where you can stop adding new money and let compounding finish the job), and a Monte Carlo sensitivity view that shows how sequence-of-returns risk and return assumptions bend your timeline. It's the Coast FI calculator and FIRE projection dashboard you'd build yourself if you had the weekend — produced in a single conversation. The skill ships with four bundled resources that do the heavy lifting silently: a FIRE vocabulary reference covering Coast FI, Barista FI, Lean/Regular/Fat, Trinity Study, and the 4% rule; a deep-dive on safe withdrawal rate research and sequence-of-returns risk that informs the 'What to watch' section; an HTML dashboard template it adapts to your numbers; and a canonical Google Sheets retirement projection spreadsheet you paste directly and use as your live tracker going forward. Built for people already in the FIRE community — you know what the 4% rule is, you've argued about 3.5% vs 3.25%, you want the Coast FI calculation done right, not approximated. Feed it your numbers and it builds the retirement timeline you've been meaning to make for two years.

Frequently asked

How do I calculate my Coast FI age based on current savings?

Give the skill your current age, invested assets, expected real return, and target retirement age (default 65). It solves FI_number = current_assets × (1+r)^(target_age − coast_age) and prints your Coast FI age as a first-class output. If you're already past Coast FI, it says so explicitly.

What FIRE projection dashboard handles lean, regular, and fat scenarios in one view?

This one. The dashboard renders all three side-by-side — lean FIRE at $40k expenses, regular at your stated number, fat FIRE at $100k — each with its FI number (25× expenses at 4% SWR), years to FI, projected age, and monthly savings required. You see the lifestyle-vs-timeline tradeoff at a glance.

Can I run a lower real return assumption like 5% instead of 7%?

Yes. Tell it to rerun at 5% real and it recomputes the entire dashboard — years to FI extends, Coast FI age pushes later, the Google Sheets formulas update with the new return in the input cell. The Monte Carlo also varies return draws via 15% SD so you see the distribution, not just the point estimate.

Will this give me individualized tax or Roth conversion advice?

No. The skill models scenarios and projection math — it explicitly declines security-specific buy/sell recommendations and tax-bracket strategy. For Roth conversion ladders or estate planning, it directs you to a fee-only CFP. The dashboard itself is asset-allocation-agnostic.

Does the output stay live after the chat ends, or do I have to rerun it?

The Google Sheets formula block is the live version — paste it into A1 of a blank sheet and the entire 60-year projection computes automatically. Update your input cells anytime and the FI number, Coast FI age, and year-by-year balance all recalculate without rerunning the skill.

Install — no Terminal required

After checkout you land on a page with a one-click download and a pre-built install prompt. Pick the AI you already pay for — both packages are included, so you can't pick wrong.

What you'll see the second your payment clears

Your license key

ST-XXXX-XXXX-XXXX · permanent

Pre-built install prompt⧉ Copy

ChatGPT package (ZIP)⬇ Download

No setup work before you buy — copy, paste, done.

Have Claude Pro, Max, or Team?

Copy the prompt, paste into Claude

Copy the pre-built install prompt from the success page, paste it into any Claude Code chat, and Claude installs the skill itself — about 10 seconds. Using the app instead? Drop the downloaded folder into a Claude Project's knowledge and ask Claude to use it.

Have ChatGPT Plus or Team?

Build a Custom GPT — ~2 minutes

Click Download ChatGPT package (included with every purchase).
Unzip it — inside is a SETUP.md and a knowledge/ folder.
Go to chatgpt.com → your profile → My GPTs → Create a GPT → Configure.
Paste the Name, Description, and Instructions from SETUP.md into the matching fields.
Under Knowledge, upload every file in the knowledge/ folder.
Click Create/Save, open your GPT, and describe your task in plain English.

A paid plan on either platform is required — Claude (Pro, Max, or Team) or ChatGPT (Plus or Team). Comfortable with Terminal? A one-line npx skilltree-network install path is available too.

Find your FI date and Coast FI age in one shot

What it does

Frequently asked

Install — no Terminal required

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