Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Emergency fund target
$22,800
Amount still needed
$17,800
Months to reach target
44.5
Psst — share this and help Rex grow
One click, a permanent link with your numbers baked in.
How to use this
- 1Enter essential monthly expenses ($).
- 2Enter months of coverage desired.
- 3Enter current emergency savings ($).
- 4Enter monthly amount you can save ($).
- 5Read your emergency fund target on the right — it updates as you type.
- 6Hit Share to keep the scenario or send it to someone.
About this calculator
An emergency fund is sized off your essential monthly expenses — housing, food, utilities, insurance, minimum debt payments — not your total spending, and the number of months' cushion you want depends on job stability and household income sources. This calculator multiplies your essential monthly expenses by your target number of months and shows how much more you need to save and how long it will take at your current savings rate.
Worked example
Using the values the calculator loads with:
Inputs
- Essential monthly expenses: 3800 $
- Months of coverage desired: 6
- Current emergency savings: 5000 $
- Monthly amount you can save: 400 $
Results
- Emergency fund target: $22,800
- Amount still needed: $17,800
- Months to reach target: 44.5
What each field means
Inputs
- Essential monthly expenses ($)
- The essential monthly expenses used in the calculation, measured in $. Starts at 3800 $ so you have a working example on load.
- Months of coverage desired
- The months of coverage desired used in the calculation. Starts at 6 so you have a working example on load. Accepted range: 1–12.
- Current emergency savings ($)
- The current emergency savings used in the calculation, measured in $. Starts at 5000 $ so you have a working example on load.
- Monthly amount you can save ($)
- The monthly amount you can save used in the calculation, measured in $. Starts at 400 $ so you have a working example on load.
Results
- Emergency fund target
- Returned as a money amount in US dollars and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Amount still needed
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Months to reach target
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
How much do I need for an emergency fund?
With $3,800 in essential monthly expenses and a 6-month target, you need $22,800 total; with $5,000 already saved, that's a $17,800 shortfall, which takes about 44.5 months at $400/month.
Why 3-6 months of expenses?
3 months suits dual-income households with stable jobs; 6-12 months is safer for single-income households, freelancers, or commission-based earners with less predictable pay.
Should I use total spending or just essentials?
Use essential expenses only — housing, utilities, groceries, insurance, minimum debt payments — since discretionary spending like dining out and entertainment is the first thing you'd cut during a real emergency.
Where should the fund be kept?
A high-yield savings account is standard — liquid and safe, but separate enough from checking that it's not tempting to dip into for non-emergencies.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). How Much Do I Need for an Emergency Fund?. Retrieved from https://www.revenuelab.fyi/toolbox/how-much-do-i-need-for-emergency-fund
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/how-much-do-i-need-for-emergency-fund" target="_blank" rel="noopener">How Much Do I Need for an Emergency Fund? — RevenueLab</a> (2026).</p>
Source: [How Much Do I Need for an Emergency Fund? — RevenueLab](https://www.revenuelab.fyi/toolbox/how-much-do-i-need-for-emergency-fund) (2026).