Emergency Fund Calculator

How much emergency fund do you actually need?

The rule you have heard is "3 to 6 months of expenses". The part people get wrong is the word expenses. It does not mean your salary, and it does not mean your normal spending. It means the stripped-down number your household costs to run in a month when the income stops: rent or mortgage, utilities, groceries, insurance premiums, transport to interviews, childcare you cannot cancel, and the minimum payments on any debt. Restaurants, streaming tiers, holidays and the gym come out of that number, because in the month you need this fund those things stop.

That distinction usually cuts the target by 25 to 40 percent, which is exactly why so many people give up before they start. A household spending $4,600 a month often has essential expenses closer to $3,200 — and a six-month fund of 9,200 rather than $27,600.

Worked example: $3,200 a month, six months of cover

Target = 3,200 x 6 = 9,200. Say you already hold $4,000 in a savings account earmarked for emergencies. Your gap is 19,200 - 4,000 = 5,200, and you are 21% of the way there. Saving $400 a month, ceil(15,200 / 400) = 38 months, a little over three years. That number is uncomfortable, and it should be — it is the honest one. Three levers shorten it: raise the monthly contribution, lower the essential expense figure, or drop the target from six months to three while you build momentum.

Try the same household at a 3-month target: 3,200 x 3 = $9,600, gap $5,600, 13 months at $400. Many planners suggest hitting the 3-month mark first, then continuing to 6 without changing anything except the target in this calculator. Windfalls change the shape too — a $2,500 tax refund cuts more than six months off the timeline at that contribution rate.

The risk matrix: choosing 3, 6, 9 or 12 months

The number of months is a proxy for one question: how long would it take to replace your income? Two salaried workers in the same household, different employers, no dependants, in a city with a deep job market — 3 months is defensible, because a single job loss only removes part of the income. One primary earner, a mortgage and children — 6 months, because the whole income can disappear at once and the fixed costs cannot flex.

Push to 9 or 12 months when income is lumpy or the job search is long: freelancers and contractors with irregular invoicing, commission or bonus-heavy pay, business owners, single-income families, anyone on a visa tied to employment, and specialists — a senior geologist or a niche academic may need six months just to find a posting that exists. Households with a chronic medical condition or an older home and an older car should also skew higher, because their "unexpected" costs arrive more often than average.

Why a high-yield savings account, not investments

Emergency money has one job: be there, in full, on the day you need it. That rules out anything that can be worth less than you put in. US savers should use an FDIC-insured high-yield savings or money market account; UK savers an FSCS-protected easy-access account. Rates on these accounts have run in the 3.5 to 5 percent range recently — not wealth-building, but enough that inflation does not quietly eat the fund.

The argument against investing it is not theoretical. Recessions cause both halves of the problem at once: the same conditions that trigger layoffs push equity markets down. Someone who kept a 9,200 emergency fund in an index fund in 2008 would have been made redundant into a portfolio worth around 2,000 — forced to sell at the bottom, crystallising the loss and losing the recovery. The 4 percent you might have earned in a good year is the premium you pay for the fund being intact in a bad one.

The opposite mistake is keeping it in your everyday current account. It is safe there but not separate, and money that shares a balance with your groceries gets spent by accident. Open a distinctly named account at a different institution, so a transfer takes a day and a deliberate decision.

Automate it, then stop thinking about it

Set a standing order for the day after payday. Whatever is left at the end of the month is never the same number twice, but a transfer that leaves before you see the balance is. Increase it with every raise before your spending adjusts, and route irregular money — tax refunds, bonuses, a side gig payment — straight in until the goal is hit. Once you reach the target, stop and redirect the same contribution to retirement or debt; an over-stuffed emergency fund is just an expensive habit.

What this calculator does not model

It assumes a flat monthly contribution and ignores interest earned on the balance, which is conservative — at 4 percent on a growing balance you will arrive a month or two early on a multi-year plan. It also ignores inflation on your expense figure, so revisit the number annually or after any change to rent, insurance or childcare. Finally, months of cover is a planning heuristic, not a guarantee: unemployment benefits, severance, a partner's income and a family safety net all change how long a fund lasts, and none of them are inputs here.