The idea, and the math behind it.

Traditional retirement planning draws a line at 65. Save until then, stop working, live off what you saved. FIRE (Financial Independence, Retire Early) draws a different line earlier: save hard in your 20s and 30s, retire in your 40s, live off your investments forever. Different age, same binary.

Project Optional asks a different question. Not when can you stop working, but when does work become a choice. That moment usually comes years before the age most retirement calculators are focused on, and it doesn’t ask you to stop working. It asks what you’d actually pick if the money side of your life stopped requiring the exact job you have right now.

Some things you might pick:

• Stay in the job you like, and let your investments keep growing at the same pace.
• Drop to part-time, move to a nonprofit, or take a lower-paying job you’d actually enjoy — and contribute a fraction of what you do now, because you don’t need to save as hard anymore. Your existing investments keep compounding.
• Take the sabbatical you keep putting off, without wondering if it’s financially reckless.
• Weather a layoff without panic, because the runway isn’t a mystery number.
• Start something of your own that pays nothing for the first few years, and know exactly how long you can afford to let it be small.

Reaching Optional at 49 doesn’t mean not working at 49. It means at 49, you get to actually pick what work looks like. If what you pick brings in any income at all, your number keeps growing anyway.

That’s what this whole thing is trying to give you: not a stop date, but a set of choices that open up sooner than you thought they would.

Work becomes optional when your investments are big enough to cover your yearly spending, without you having to keep adding to them. Here’s the target:

At the standard 4% withdrawal rate, that comes out to 25 times what you spend in a year. If you spend $60,000, your Optional Number is $1.5 million. This is the same math behind the classic Trinity Study, framed as a savings goal instead of a spending rule.

When you see “7% expected return” anywhere in the app, that number already accounts for inflation. Your Optional Number stays the same in today’s dollars from now until you reach it.

A lot of retirement calculators do this wrong. They grow your money at 7% (which most people read as “the average stock return after inflation”), and then also inflate your spending target every year on top of that. Doing both counts inflation twice, and pushes your projected date years further out than it should be.

On one real example — $301,000 saved, $3,000/month added, $120,000/year spending — the double-counting method said 29.7 years. The correct method said 17.8 years. Same inputs. Twelve years of difference.

If retirement calculators have ever made you feel further behind than you should, this is often why.

Each of your accounts grows one month at a time, for 50 years. Every month, we add your contribution, apply that month’s growth, and drop in any lump sums dated for that month:

Yearly return rates get converted to a monthly equivalent using compound math:

Not annualRate ÷ 12, which would understate your growth by about half a percent a year. Small in a month, real money over decades.

When we say you’ve “reached Optional,” we mean your investment accounts add up to your Optional Number. That includes:

• 401(k), 403(b), 457
• Traditional IRA, Roth IRA
• HSA investments
• Taxable brokerage
• Investable cash
• Other investments

It doesn’t include:

• Your home (see the next section)
• Your emergency fund
• Personal property and vehicles
• Unvested or speculative compensation
• Future money you haven't entered as a lump sum

The idea: things you can’t easily turn into monthly income don’t belong in a target that’s all about generating income.

If you own a home, that equity is real money you have. You’ll see it counted in your net worth in the Scenarios Lab. But we keep it out of your Optional Number for two honest reasons:

• You can’t pull 4% a year out of the house you live in. The Optional Number is really a shortcut for “how much do I need invested to have income without going to work?” A roof over your head doesn’t do that.
• Houses don’t grow at 7% real. Long-term, US housing has returned closer to 1% after inflation. Applying stock-market growth to a house would make your projection look better than it actually is.

When you’re ready to actually turn home equity into investable money, the Sell the House scenario in the Scenarios Lab models the sale at whatever future date you pick and drops the proceeds into an account you choose.

Not everyone knows exactly how much goes into their 401(k) versus their brokerage each month. You don’t have to. The Contributions section on the dashboard lets you set a total monthly or yearly savings amount on top of what your accounts show. That extra is modeled like this:

• It grows at the same 7% real return your accounts do.
• It cuts back automatically when you turn on Part-Time or Sabbatical in the Scenarios Lab, the same way your real contributions would.
• It doesn’t count as liquid cash for the Layoff cushion check. That check only uses accounts you’ve named, so it stays honest.

A few things you might expect from a full financial planning app aren’t here on purpose. Some are coming, some are a permanent no.

• No probability score. Showing you a “73% confident” number would be theater until we’ve run a proper Monte Carlo simulation across thousands of possible futures. Until then, you get straight-talk status (on track, needs attention). Monte Carlo is on the roadmap — you can vote for it.
• No taxes on withdrawals. The Life after Optional projection assumes you’re drawing your target amount pre-tax, in today’s dollars. Modeling which account to withdraw from first (taxable, then tax-deferred, then Roth, with required minimum distributions) is on the roadmap.
• No Social Security. Every projection assumes zero income once you stop working. Adding this will lower the number you actually need for anyone planning to claim. Also on the roadmap.
• No bank or brokerage sync. Every number in your account was typed by you. That’s a product choice, not a shortcoming. It keeps your financial data on your screen instead of routed through a third-party aggregator with your bank passwords.