The target is months of expenses, not a round number
Your monthly expenses are the baseline - rent or mortgage, food, utilities, insurance and the essentials that keep coming whatever happens. Multiply that by the cushion you choose: three months is the common minimum, six is the conservative end, and people with unstable income often aim higher.
The page multiplies your own number rather than assuming one, so the target is always checkable against your bank statements.
Choosing the cushion is the single biggest lever on the page, and the difference between three and six months is the difference between a fund that covers a short break and one that survives a long stretch of unemployment. Because the target is your own monthly expenses multiplied by the months you pick, it stays checkable against your bank statements - you are not being handed a foreign number, you are being shown a multiple of the one you already live on.
The gap is what you still need to save
Your current savings are subtracted from the target. If the answer is positive you have a gap to fill, and the page says how large it is in money and roughly how many months of expenses it represents. If you are already past the target, the page says so instead of pretending a surplus is a problem.
The covered number - savings divided by monthly expenses - tells you how far a real month of trouble would stretch today, which is the more honest measure of where you stand.
Why it uses today’s savings, not a retirement balance
An emergency fund has to be reachable without a penalty or a market move, so the page counts the cash you could actually spend from savings today. Retirement accounts are deliberately not part of this number: raiding a 401(k) to pay a repair is how an emergency becomes a retirement problem.
If your only savings sit in a retirement account, the honest output of this page is a larger gap, not a smaller one.
Counting today’s liquid savings rather than a retirement balance is a deliberate definition: an emergency fund has to be reachable this week without a penalty or a market move, and money tied up in a 401(k) or an illiquid investment fails that test even when its statement looks large. If all you hold is retirement money, the honest output of the page is a bigger gap, not a smaller one - which is exactly the nudge the exercise is for.
What the page deliberately does not decide
Three to six months is a starting point, not advice. How much you personally need depends on how long a job search could take in your field, whether you have a second income, and what your insurance actually covers - none of which a monthly budget captures.
The page also does not say where the money should sit. It only turns your numbers into a target, a current position and a gap, and leaves the judgment to you.
The honest value of the calculation is that it forces the choice into a number you can act on: a fund sized in months of expenses, a balance you already hold, and a gap to close. Whether you rebuild it slowly or quickly, or keep it in a checking or savings account, is a judgment the page deliberately returns to you rather than deciding for you.
What six months of expenses does not buy
The cushion is sized in months of spending, so it covers a gap in income — not a gap in income plus a medical bill plus a roof. Take the default $4,500 month and a six-month fund of $27,000. A single emergency-room visit billed at $9,000, or a furnace and a transmission in the same quarter at $12,000, eats a third to a half of that fund before any income has been lost, and the months it covers quietly fall from six to four or three. The same arithmetic applies to the insurance deductible you would have to pay in a real emergency: if the deductible is $3,000, it belongs inside the target, not outside it.
The other thing the fund does not know is how long your income would actually stop. A salaried job search averages months; contract work can stop on a Friday and resume in three weeks, which argues for a smaller fund and more attention to the size of the next invoice. The page multiplies your number by the months you choose and prints the gap — the part that decides whether six months is right is your own income shape, and no calculator can read that off two fields.
Danfio