ReviewedEducational article · Updated Oct 2026
Key takeaways
- Start from your essential monthly expenses, not your income.
- Common guidance is three to six months of essentials, but the right figure depends on your situation.
- Divide the target by your monthly saving to estimate the timeline.
- Interest helps a little, but your savings rate does most of the work.
An emergency fund is money set aside for unexpected costs such as a job loss, a medical bill or a car repair. The goal is to avoid borrowing at a high interest rate when something goes wrong. The arithmetic of sizing one is simple.
Step 1: add up essential expenses
List the spending you could not avoid in a difficult month: housing, utilities, food, transport, insurance, minimum debt payments and similar. Leave out discretionary items. Suppose this comes to $2,500 a month.
Step 2: choose a target range
A frequently cited range is three to six months of essential expenses. For $2,500 a month that is:
- 3 months: $7,500
- 6 months: $15,000
Someone with a stable job and few dependants may be comfortable near the low end; someone with irregular income or a single household income may prefer more. This is a personal judgment, not a rule.
Step 3: estimate the timeline
Divide the target by what you can save each month. If you save $400 a month, ignoring interest:
- $7,500 takes 18.75 months (about 19 months).
- $15,000 takes 37.5 months (about 3 years and 2 months).
Interest in a savings account will shorten this slightly. Use the savings goal planner to include a rate and a starting balance.
The simplest estimate of how many months it takes, before counting interest.
Where to keep it
An emergency fund is meant to be available quickly and to hold its value, so people commonly keep it in an easily accessible savings account rather than in assets that can drop in price. Check the interest rate and any withdrawal limits for the accounts available where you live.
Inflation matters: if your essentials cost more next year, your target rises too. Review the figure periodically.
What this leaves out
The figures above are hypothetical. Your own target depends on your income stability, dependants, insurance cover and other resources. This article is educational and is not personal financial advice.
Common mistakes to avoid
- Counting discretionary spending in your target, which makes the goal harder than necessary.
- Keeping the money where it is hard to reach or where its value can fall quickly.
- Dipping into it for non-emergencies without a plan to refill it.
- Never revisiting the number as your expenses change.
Quick glossary
- Essential expenses
- Costs you must pay even in a difficult month.
- Runway
- The number of months your savings could cover your essentials.
- Liquidity
- How quickly money can be turned into cash without losing value.
Try it yourself
List your essential expenses for one month, multiply by 3 and by 6 to get a range, then divide each by the amount you can save per month to estimate the time needed.
Further reading from official sources
These are general educational resources. Rules and figures differ by country, so look for your own country’s equivalent.
Related reading
This article is for general educational purposes only and is not financial advice. Examples use simplified, hypothetical numbers and ignore taxes, fees and personal circumstances. Consider speaking with a qualified professional before making financial decisions. See our full disclaimer.