Your savings rate decides the year you're free.
Enter what you save each year — including your 401(k) and employer match — and what you spend. That's it. This tool works out your savings rate and shows the number Mr. Money Mustache made famous: how many years until you're financially independent, and why your rate, far more than your income or your returns, sets the date. No sign-up, no gated number.
You're saving 50% of your take-home — $40,000 of $80,000 a year. That rate, not your income, is what sets the date.
ALREADY HAVE SAVINGS?start from $0
ASSUMPTIONS10% → 6.8% real · 3% infl
Drag across the curve. At your current 50% rate you reach FI in 16 years. Notice how steep it is at the left and how it flattens past ~70% — the first few points of savings rate buy you far more time than the last few.
The four levers that move your date
You're at a 50% savings rate today, reaching FI in 15.1 years (around 2042). Pull any lever and watch the date move. Each starts from your numbers and uses the same 6.8% real return as the calculator above — so nothing here disagrees with your headline.
Raise your take-home and bank the increase — lifestyle flat.
Cut a recurring cost. The money saved AND the lower target both pull the date in.
Assume a stronger market. It helps — but less than you'd think.
Add a side stream and save all of it — a second engine on the savings rate.
The two spending-side levers — spend less and saving a raise instead of inflating into it — do the heavy lifting, because a dollar of spending cut works twice: it's a dollar more saved and $25 less you ever need. A higher return helps, but it's the weakest of the four. That's the whole lesson of the savings rate.
What is your savings rate?
Your savings rate is the share of your take-home pay you keep instead of spend:
savings rate = (take-home pay − spending) ÷ take-home pay × 100
Work it with real numbers. If you take home $60,000 after tax and live on $42,000, you save $18,000 a year — a 30% savings rate. That single percentage, as you'll see, matters more for your retirement date than your salary or your investment return.
Use take-home (after-tax) pay, not gross. Gross income includes money you never actually control — income tax, payroll tax — so a “savings rate” measured against gross flatters the number and breaks the link to the 25×-spending target that sets your finish line. Net pay is the pool you genuinely choose to save or spend, so it's the honest denominator. (This is the most common mix-up in savings-rate math — when a source quotes a higher number, it's usually measuring against gross.)
One inclusion people miss: count your 401(k), IRA, and any employer match as savings — even though that money never lands in your bank account. It's still dollars working for your future, so leaving it out understates your real rate, often badly. That's why the calculator above asks for what you save directly, rather than backing it out of your paycheck: the saved amount is the one number that's easy to get wrong when pre-tax contributions are invisible on your pay stub.
Why your savings rate sets your date
Here's the idea that launched a movement, which the writer Mr. Money Mustache called “the shockingly simple math behind early retirement.” Your time to financial independence depends almost entirely on your savings rate — not on how much you earn. Someone saving 50% of a modest take-home reaches FI years before someone saving 15% of a large one.
It works because a higher savings rate pulls two levers at once. Save more of your take-home and you (1) pile up money faster, and (2) live on less — which lowers the finish line itself. The finish line is the 4% rule: a portfolio of about 25× your annual spending can sustainably fund that spending for life (drawing ~4% a year). Cut $1,000 of annual spending and you don't just save $1,000 more — you also drop $25,000 off the target you're chasing. That double effect is why the curve above bends so hard.
And it's non-linear. Going from a 10% to a 20% savings rate buys you roughly a decade; going from 70% to 80% buys you barely a year. The first points of savings rate are worth far more than the last — which is the practical case for getting your rate up early, and the reason chasing an ever-higher rate past ~70% has diminishing returns.
The classic table — and your version of it
This is the famous table everyone screenshots, frozen at a conservative 5% real return — now sitting next to the same math at your return assumption, live:
| Savings rate | Years to FI MMM · 5% real | Years to FI your 6.8% real |
|---|---|---|
| 10% | 51.4 | 42.4 |
| 20% | 36.7 | 31.2 |
| 30% | 28.0 | 24.4 |
| 40% | 21.6 | 19.3 |
| 50%you ≈ 50% | 16.6 | 15.1 |
| 60% | 12.4 | 11.5 |
| 70% | 8.8 | 8.3 |
| 75% | 7.1 | 6.8 |
| 80% | 5.6 | 5.4 |
| 90% | 2.7 | 2.6 |
The left column is Mr. Money Mustache's original table — at a conservative 5% real return. The right column is the very same math at your 6.8% real return, recomputing as you change the assumptions above. At our 6.8% real default these come down a year or two — try the calculator with your own numbers. Either way the shape is identical: the date depends on the rate, not the income behind it.
What actually moves the date
The interactive block above lets you pull each lever and watch the years move; here's what's happening underneath. There are really only four: earn more and save it, spend less, earn a return, and add side income. They are not equal.
Spending less is the strongest, because it's the one that counts twice — more saved and a smaller target, together. Earning more helps only if you save the raise; inflate your lifestyle to match and your rate — and your date — don't budge. A higher return is real but the weakest lever over the timescales that matter, and it's the one you control least. Side income is just another way to push the rate up. The takeaway: the date lives on the spending side of your budget far more than the income side.
This page shows the textbook curve. FIRE Projection runs it on your real numbers as they change month to month.
What's a good savings rate?
The traditional personal-finance answer is 10–15%, the rate that lands a normal career at a normal retirement in your mid-60s. The FIRE answer is higher on purpose: 30–60% is the band that pulls retirement decades earlier, and the math above shows why — 50% roughly halves a 40-year timeline.
Be honest with yourself about where you are, though. A 50% rate is far easier on a high income than a modest one, because below a certain point your spending is mostly rent, food, and getting to work — not optional. If a 50% rate isn't realistic right now, that's fine: the curve is steepest at the low end, so even moving from 10% to 20% is worth about a decade. Aim for the next ten points, not a number off someone else's spreadsheet.
How to actually raise your savings rate
There are only two sides to the equation, and both count. On the spend side — the side that works twice — go after the big three first: housing, transport, and food, which dwarf the small stuff. A smaller place, one car instead of two, cooking most nights: each cut lowers your target and raises your rate, permanently. Skip the latte math; chase the recurring bills.
On the income side, the rule is simple: when your pay goes up, bank the raise instead of inflating into it. A bonus, a new job, a side stream — route it straight to investments and your rate jumps without any change to how you live. The fastest savers do both at once: hold the line on spending while income climbs, and the gap (your savings) widens from both ends.
What this calculator assumes
The defaults are deliberately conventional, and every one of them is a control you can move. All figures are in today's dollars, pre-tax, and start from zero unless you tell it otherwise.
- 10% nominal return — the long-run U.S. stock-market average, before inflation.
- 3% inflation — netting a 6.8% real return, so everything stays in today's dollars.
- 4% safe withdrawal rate — the Trinity Study baseline, i.e. a 25× target. Switch to 3.5% (≈29×) for a more cautious finish line.
- Start from $0 — the pure MMM thesis. Toggle in a starting balance to count what you've already invested.
- Savings is measured against take-home pay. The model adds your savings at year-end and compounds annually.
Full method, sources, and edge cases: FIRE Projection methodology & sources →
Educational, not financial advice. Markets don't deliver a steady return, sequence-of-returns risk is real, and taxes depend on your accounts and where you live. The savings-rate math is a clean way to build intuition and frame the question — not a plan to act on without advice tailored to your situation.
This page shows the math. The app tracks it.
The curve above is the textbook. Real life is messier — your spending drifts, your income changes, a windfall lands. FIRE Projection takes your real savings and spending in plain dollars, works out your savings rate for you, and projects the date you hit financial independence — then lets you pull the same levers and watch the date move.
- Dollars in, rate out — enter what you save and spend; it computes the rate. No percentages to guess, no salary to enter.
- A real levers engine — save more, spend less, higher return, a one-time inheritance — baseline vs. scenario, side by side.
- It moves as your life does — update your numbers and the date updates with them.
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