How much emergency fund should I have? Size it from your ledger

"How much emergency fund should I have?" is the most common savings question I am asked, and the answer people have usually already heard — three to six months of expenses — is right in shape and useless in detail. Three to six months of what? Why three and not five? Nobody can act on a range that wide, so most people pick a round number and hope, or postpone the whole thing.

The better answer is a calculation, not a rule of thumb, and everything it needs is already in your ledger. This post does the calculation on real numbers, then covers where to keep the money and how to build it when the amount looks far away.

There is a timely reason to do it this week. The Federal Reserve announces a rate decision today, 16 September, and markets have been expecting the first increase since 2023. Savings rates will move a little either way. By the end you will see why the rate on your emergency fund matters far less than its size.

Start with what the fund is for#

An emergency fund pays for the month when income stops or a large unplanned cost arrives: a job loss, a medical bill, a car that will not start, a client who does not pay. It is not for the annual insurance premium or the phone you knew you would replace. Those are predictable, and predictable costs belong in the budget as recurring bills or savings goals. If the same "emergency" happens every year, it is a bill.

That distinction decides what you count. The fund needs to cover essentials — the spending that continues when everything optional stops — not your average month. Average months include restaurants, subscriptions and the gym, and in a real emergency those are the first things you cut. Sizing the fund on total spending makes the target a third larger than it needs to be, which is one reason so many people never reach it.

Step 1: read your essentials from the ledger#

Open the last three months of entries and pull out only what you would still have to pay if your income stopped tomorrow: housing, utilities, groceries (not dining out), the transport that gets you to work, insurance, minimum debt payments, childcare, prescriptions. Average the three months so one unusual bill does not skew it.

Here is that read for one person on a $3,400 take-home salary, renting in a mid-sized city, with a car and a small personal loan:

• Rent — $1,150
• Utilities and internet — $140
• Groceries — $420
• Transport: fuel, insurance, parking — $260
• Phone — $35
• Health insurance and prescriptions — $90
• Loan minimum payments — $120
• Essentials per month — $2,215

Her total spending averages $3,150 a month. The essentials are $2,215 — 70% of it. That gap is the first useful thing the ledger tells you: three months of spending would be $9,450, but three months of essentials is $6,645. Same person, same safety, $2,805 less to save.

If you keep a Personal and a Business book, as freelancers should, read the Personal book only; a business tax reserve is a different pot with a different job, and mixing them makes both numbers wrong.

Step 2: choose the number of months honestly#

Three months is the floor for someone with a steady salary, a second household income, and a job that is easy to replace. Add a month for each of these that applies:

• You are the only earner, or you have dependants.
• Your income is variable — commissions, contracts, freelance work.
• Your field hires slowly, so a job search would take longer than a quarter.
• Your health costs are unpredictable or your insurance excess is high.
• You have no other buffer: no partner's income, no family who could help, no line of credit you would be willing to use.

Most salaried people land at three or four; most self-employed people land at six; a sole earner on a variable income in a slow-hiring field should not feel odd at nine. The multiplier is a judgement, but a judgement about five yes-or-no facts, not a feeling.

Our example is a salaried employee in a specialised role that typically takes a few months to rehire. One factor applies, so she picks four months:

$2,215 × 4 = $8,860.

That is her number. Not "three to six months of expenses" — $8,860, written down as a goal with a name.

Step 3: work out how long it takes — and what actually speeds it up#

She has $1,900 saved already, so the gap is $6,960. Her budget can commit $350 a month to the fund — the savings share of a 20% bucket that also carries extra loan payments (the 50/30/20 post shows that split on a paycheck like hers).

Now the part the rate news is about. A CBS News round-up from 8 September puts the top high-yield savings accounts around 4.10% APY and the average traditional savings account at 0.38%. Here is how long the $8,860 takes to reach at each rate, interest compounded monthly, at two contribution levels:

Read the table across, then down. Moving from an ordinary savings account to a high-yield one saves her about one month. Finding another $100 a month saves her four. A quarter-point change in the Fed's rate, applied to the full $8,860 once she has it, is worth about $22 a year. The 4.10% itself is worth around $363 a year on the finished fund — real money, worth having — but it is not the lever that gets the fund built. The contribution is.

That is the lesson of this week's rate decision for emergency savings: take the better rate if it is a five-minute switch, then stop watching the Fed and start watching the transfer.

Where to keep it#

The requirements are simple and rule out most clever options.

Separate from your spending account. Money that sits next to the grocery budget gets spent on groceries. A distinct savings account, ideally at a different bank from your card, adds exactly the friction you want.

Available within a day or two. A high-yield savings or money market account qualifies. A fixed-term deposit does not, unless you accept losing the interest on early withdrawal; if you want part of the fund at a fixed rate, keep at least one month of essentials instantly accessible and lock only the rest.

Not invested. The fund's job is to be worth the same amount on a bad day. Shares, funds and crypto are for money you will not need for five years, and emergencies have a habit of coinciding with markets falling.

In the currency of your essentials. If your rent and groceries are in euros, an emergency fund in dollars carries an exchange-rate risk you did not ask for. Hold the fund where the bills are, and record it in the currency it sits in rather than as a converted guess.

Building it when the number looks far away#

Nineteen months is a long time to stare at one goal, and the surveys show how often the plan quietly stops. In Bankrate's 2026 emergency savings survey (fielded December 2025), only 30% of US adults said they would pay a $1,000 emergency from savings, 24% had no emergency savings at all, and 63% said they would need at least six months of expenses to feel comfortable — while 27% had that much. The Federal Reserve's household well-being report from May 2026 found 55% of adults had three months of expenses set aside, down from 59% in 2021.

The gap between what people say they need and what they hold is not mostly about income. It is about a target that was never made concrete and a transfer that was never automated. Three things close it:

1. Set milestones, not one finish line. The first $1,000 (you have just left the group who would put the emergency on a card). Then one month of essentials — $2,215 in our example. Then the full target. Each one is a real change in how exposed you are.
2. Move the money on payday, automatically. A standing transfer the morning your salary lands. Whatever you save "at the end of the month" is whatever the month did not take, which is usually nothing.
3. Treat windfalls as fund money until the fund is full. A tax refund, a bonus, a month where the wants bucket comes in under. In the example, one $700 bonus removes two months from the timeline on its own.

If you are paying down expensive debt at the same time, build the first milestone — one month of essentials — before you accelerate the debt, then send the rest of the 20% to the highest rate. The snowball and avalanche post shows why the extra payment matters more than the method there too.

Keeping the number current#

An emergency fund target goes stale. Rent goes up, a loan gets paid off, a child arrives, you go freelance. Re-read the essentials once or twice a year, or whenever a recurring bill changes, and adjust the goal. The ledger changes when your life does; a rule of thumb never notices.

What to ask an advisor about it#

If you keep your books in Azno, the calculation above is three questions rather than an evening with a spreadsheet:

• "What did my essential expenses average per month over the last three months — housing, utilities, groceries, transport, insurance and minimum payments only?"
• "Set up a savings goal called Emergency fund for four months of that, and tell me how long it takes at $350 a month."
• "Which of my recurring bills would stop if I lost my income, and which would carry on?"

The first is a read of your entries, category by category, with the total shown. The second arrives as a proposal card — the goal, the target, the monthly amount — and nothing is written until you approve it. The third is the honest version of the essentials list, drawn from the recurring bills already in your ledger rather than from memory. If you have not set your books up yet, creating an account and entering three months of bills is enough to answer all three; the number at the end will be yours, not a rule's.