Emergency Fund Calculator
Work out how big your emergency fund should be and how long it takes to build. Compare 3, 6, 9 and 12 months of runway. Free, private, no signup.
What you already have set aside for emergencies.
What you can move into the fund each month.
How the timeline changes with runway
| Runway | Target | Gap | Time to fund |
|---|---|---|---|
| 3 months | $8,040 | $5,040 | 1 yr 1 mo |
| 6 months | $16,080 | $13,080 | 2 yr 9 mo |
| 9 months | $24,120 | $21,120 | 4 yr 5 mo |
| 12 months | $32,160 | $29,160 | 6 yr 1 mo |
Assumes no interest, so treat every timeline as a conservative floor.
How an emergency fund target is calculated
The formula is deliberately boring: target = essential monthly expenses × months of runway. Subtract what you already have and you get the gap; divide the gap by your monthly contribution and you get the number of months until the fund is full. That's all this calculator does — no interest, no assumed raises, no fine print.
The three-to-six-month range is the standard advice repeated by the Consumer Financial Protection Bureau and by large fund providers such as Vanguard: enough to absorb a job loss or a major repair without reaching for a credit card. Lean toward the higher end — or past it — if your income is irregular, you're self-employed, you're the only earner in the household, or hiring in your field is slow. Lean lower if you have very stable dual incomes and strong disability cover. The 3 / 6 / 9 / 12 table below the result exists so you can see what each choice actually costs you in months of saving before you commit to one.
One important detail: use essential expenses, not your full spending. In a real emergency you cut the gym, the streaming stack and the takeaways. Counting them inflates the target and makes the whole project feel hopeless, which is the most common reason people never start.
Building the fund is a habit, not a decision — it's one recurring transfer repeated thirty or fifty times. That's exactly the kind of thing that quietly slips. Set the transfer as a recurring habit in HabitBox, tap it off on payday, and let the streak carry the motivation. HabitBox is a habit tracker for iOS and Android that keeps your data on your device and needs no account.
Frequently asked questions
How big should my emergency fund be?+
The common guidance from consumer-finance sources such as the CFPB and large fund providers like Vanguard is three to six months of essential expenses, with a longer cushion if your income is variable or a job search in your field takes a while. Essential means the bills you can't switch off: housing, utilities, food, transport, insurance and minimum debt payments — not holidays or subscriptions. This calculator multiplies your essentials by the runway you pick and shows 3, 6, 9 and 12 months side by side so you can decide.
Should I use my take-home pay or my expenses?+
Expenses. An emergency fund is meant to keep the lights on while income stops, so what matters is your bare-bones monthly outflow, not your salary. Using income usually overshoots and makes the target feel impossible. Add up only the categories you'd still be paying if you lost your job tomorrow.
What if I can't contribute anything each month right now?+
Then the tool shows your target and the remaining gap but no timeline — there's nothing to divide by, so a projection would be meaningless. Even a very small recurring amount changes that. Many people start with a $1,000-ish starter cushion first, then build toward the full three-to-six-month figure once high-interest debt is under control.
Does this account for interest on my savings?+
No, and that's deliberate. The timeline assumes plain deposits with zero growth, which makes it a conservative floor. If your fund sits in a high-yield savings account or money-market fund, interest works in your favour and you'll finish a little sooner. An emergency fund should stay in something liquid and stable, not invested in stocks, so the growth won't change the picture dramatically anyway.
Is this calculator free and private?+
Yes. It runs entirely in your browser — nothing you type is sent anywhere or stored on a server. There's no account, no signup, and no tracking of your numbers.
Make the monthly transfer a habit
Knowing the number is the easy part — moving the money every single payday is what actually fills the fund. HabitBox lets you set a recurring savings habit, log it in one tap and keep the streak alive. iOS and Android, data stays on your device, no account needed.
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