Having money set aside for the unexpected is one of the most repeated pieces of financial advice, but two practical questions usually go unanswered: how much exactly to save, and where to keep that money so it doesn't lose purchasing power while it waits for an emergency that may never come.
How much to save: it depends on how stable your income is
The most common rule is to save between 3 and 6 months of essential expenses — not your full income. Essential expenses are housing, food, transportation, fixed bills, and other costs that would keep existing even if you went without income for a while. Subscriptions, entertainment, and non-essential purchases don't count toward this.
What the generic rule doesn't explain is that the right number within that range (or even above it) depends on how predictable your income is:
- Someone with a stable job, in a sector with low layoff risk, can reasonably feel safe with a fund closer to 3 months.
- Someone self-employed, freelancing, or with variable income (commissions, project-based work, no contractual stability) should aim for 6 to 12 months, because both the odds of a bad month and the time it takes to recover income are higher.
Where to keep it: liquidity first, return second
The most common mistake is choosing where to park the fund based on which option pays the most, as if it were a regular investment. An emergency fund isn't about maximizing returns — it's about having the money available the same day you need it, without losing value on withdrawal.
That immediately rules out anything with a lock-up period or an early-withdrawal penalty. Options that combine real same-day liquidity with safety are few, and they vary by country. In Brazil, where this site operates, the most common ones are:
- Savings account (poupança): instant, guaranteed liquidity up to a coverage limit, but historically lower returns than the alternatives below.
- A CDB (bank certificate of deposit) with daily liquidity, paying 100% of the CDI or more, from a deposit-insured bank: the same practical safety as a savings account, usually with a better return.
- Tesouro Selic (Brazil's equivalent of a short-term government bond with daily liquidity): backed by the National Treasury, with funds available in about one business day.
Right now the Selic rate (Brazil's benchmark interest rate) sits at 14.25% a year and the CDI at approximately 14.15% a year — at this level, a daily-liquidity CDB paying 100% of the CDI earns considerably more than a traditional savings account for the same idle money, without giving up same-day access. Because these benchmarks change every time the central bank meets, it's worth checking the current value before deciding. If you're outside Brazil, look for the local equivalent: a high-yield savings account or a money market fund with daily liquidity and low risk.
To compare a savings account, CDB, and similar fixed-income options side by side with your own numbers, use the investment comparison calculator. And to figure out exactly how much you need to save based on your monthly expenses, use the emergency fund calculator.
A common mistake is leaving the fund sitting in a checking account earning nothing, "so you don't forget it's set-aside money." The fix is keeping it in an investment account separate from your everyday account — the money stays just as accessible as before, but it starts earning something while it waits to be used.
Emergency fund or paying off debt first?
If you have expensive debt outstanding (especially credit card revolving debt) and no emergency fund at all yet, it usually makes more sense to build a small starter fund first — enough to avoid taking on more expensive debt at the first emergency — and only then focus on paying off the debt. Once the revolving debt or other high-interest debt is handled, go back to topping up the fund to the recommended 3 to 6 months.
To understand how to prioritize between several debts at once, see Snowball vs. avalanche: which debt payoff strategy to use.
This content is educational and does not replace personalized financial advice.