A sabbatical is a better FIRE calculator

A spreadsheet can estimate whether someone can stop working. It cannot show whether they will want to, what an ordinary week without work will feel like, or which costs disappear with the paycheque. If I were considering a permanent exit, I would use a temporary leave to turn those assumptions into evidence.

This experiment is not available to everyone. It works only when the employer approves the leave, the time away is affordable, and returning to work is realistic.

Run it in three phases: price the leave, live the leave, then review what happened before making a permanent decision.

Price the leave

I would start with the employment terms, not the travel itinerary. Ask for the leave dates, return terms, pay, benefits, insurance, pension treatment, and employee premiums in writing. Do not assume one approval answers every question; confirm each item with the employer or organization that administers it.

Then build a month-by-month budget with the Financial Consumer Agency of Canada Budget Planner or a comparable worksheet. Remove the missing pay. Add benefit premiums, replacement coverage, travel or project costs, taxes, and the cost of returning to work.

I would also keep a return-to-work reserve outside the spending budget. Plans and timing change. The reserve lets the experiment end without an immediate investment sale, expensive debt, or an unplanned withdrawal from money set aside for retirement.

Live the leave

Track every expense and label it either ordinary or one-time. A flight, tuition payment, or renovation is real spending, but it should not become twelve months of projected retirement spending. A temporarily paused expense can make the leave look cheaper than ordinary life too.

Schedule at least one deliberately ordinary week. No major trip. No heroic list of projects. See what happens when Tuesday has to be designed from scratch.

Notice what the spreadsheet missed: daily structure, social contact, purpose, expectations at home, and how much identity came from paid work. Maybe the goal is not to stop working. Maybe it is to do different work for fewer hours.

A leave cannot imitate permanent retirement perfectly because it has an end date. It can still expose assumptions that were invisible while working full time.

Review the evidence

After returning, compare the budget with what happened. Remove one-time project costs from ordinary monthly spending. Record benefit gaps, taxes, friction at home, and which routines survived after the novelty faded.

Use the result to choose one of three directions:

• Go: The spending was supportable, the ordinary weeks worked, and the financial plan still holds after adding overlooked costs.
• Go back: The leave exposed a cash, benefit, routine, or relationship problem that makes a permanent exit premature.
• Modify: A shorter workweek, different job, later date, larger reserve, or periodic leave would solve more of the actual problem than full retirement.

"Go back" is not a failed test. Finding an expensive mistake before resigning is useful. "Modify" may also show that financial independence has value before retirement: a reserve can support a better job or a shorter break without funding an entire lifetime.

A calculator is good at extending assumptions. A sabbatical is good at finding out which assumptions deserve to be extended.