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
Target buffer
$28,350
Months of cover
6.8
Still to save
$22,350
Months to fully fund
24.8
Psst — share this and help Rex grow
One click, a permanent link with your numbers baked in.
How to use this
- 1Enter essential monthly expenses ($).
- 2Enter income month-to-month swing (%).
- 3Enter longest dry spell seen (months).
- 4Enter currently saved ($).
- 5Enter can save per month ($).
- 6Read your target buffer on the right — it updates as you type.
- 7Hit Share to keep the scenario or send it to someone.
About this calculator
Salaried advice says three months. Freelancers with lumpy invoicing need more. This sizes the buffer from monthly costs, income volatility and how long a dry spell usually lasts.
Worked example
Using the values the calculator loads with:
Inputs
- Essential monthly expenses: 4200 $
- Income month-to-month swing: 35 %
- Longest dry spell seen: 2 months
- Currently saved: 6000 $
- Can save per month: 900 $
Results
- Target buffer: $28,350
- Months of cover: 6.8
- Still to save: $22,350
- Months to fully fund: 24.8
What each field means
Inputs
- Essential monthly expenses ($)
- The essential monthly expenses used in the calculation, measured in $. Starts at 4200 $ so you have a working example on load.
- Income month-to-month swing (%)
- The income month-to-month swing used in the calculation, measured in %. Starts at 35 % so you have a working example on load. Accepted range: 0–100 %.
- Longest dry spell seen (months)
- The longest dry spell seen used in the calculation, measured in months. Starts at 2 months so you have a working example on load.
- Currently saved ($)
- The currently saved used in the calculation, measured in $. Starts at 6000 $ so you have a working example on load.
- Can save per month ($)
- The can save per month used in the calculation, measured in $. Starts at 900 $ so you have a working example on load.
Results
- Target buffer
- 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.
- Months of cover
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Still to save
- 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 fully fund
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
How does the freelance emergency fund calculator work?
Salaried advice says three months. Freelancers with lumpy invoicing need more. This sizes the buffer from monthly costs, income volatility and how long a dry spell usually lasts. The underlying maths is: Months = 3 + volatility ÷ 20 + longest gap. Target = expenses × months.
What do I need to enter?
5 values: essential monthly expenses, income month-to-month swing, longest dry spell seen, currently saved, and can save per month. Each field starts with a sensible default, so you can change one number at a time and watch the result move.
What does the target buffer result mean?
It is returned as a money amount in US dollars and updates live as you edit the inputs, so you can compare two or three versions of a scenario in a few seconds.
Is this calculator free, and do I need an account?
Yes, it's free, and no account is required. Nothing you type is stored on our servers — the maths runs entirely in your browser.
How accurate is the result?
It applies the standard formula exactly, so the arithmetic is precise. Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
Who is this tool for?
It's built for anyone comparing money scenarios before committing — budgeting a payment, sanity-checking a quote, or seeing what a change in rate or term actually costs.
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). Freelance Emergency Fund Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/freelance-emergency-fund
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/freelance-emergency-fund" target="_blank" rel="noopener">Freelance Emergency Fund Calculator — RevenueLab</a> (2026).</p>
Source: [Freelance Emergency Fund Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/freelance-emergency-fund) (2026).