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
Safe monthly paycheck
$2,722
Average monthly surplus
$3,614
Tax to hold back / mo
$2,464
Annual salary to self
$32,659
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How to use this
- 1Enter lowest month last year ($).
- 2Enter average month ($).
- 3Enter tax set-aside (%).
- 4Enter safety margin on draw (%).
- 5Read your safe monthly paycheck on the right — it updates as you type.
- 6Hit Share to keep the scenario or send it to someone.
About this calculator
Pay yourself a fixed salary from a variable business. This sets a safe monthly draw from your lowest recent months and shows the surplus to hold back.
Worked example
Using the values the calculator loads with:
Inputs
- Lowest month last year: 4200 $
- Average month: 8800 $
- Tax set-aside: 28 %
- Safety margin on draw: 10 %
Results
- Safe monthly paycheck: $2,722
- Average monthly surplus: $3,614
- Tax to hold back / mo: $2,464
- Annual salary to self: $32,659
What each field means
Inputs
- Lowest month last year ($)
- The lowest month last year used in the calculation, measured in $. Starts at 4200 $ so you have a working example on load.
- Average month ($)
- The average month used in the calculation, measured in $. Starts at 8800 $ so you have a working example on load.
- Tax set-aside (%)
- The tax set-aside used in the calculation, measured in %. Starts at 28 % so you have a working example on load. Accepted range: 0–50 %.
- Safety margin on draw (%)
- The safety margin on draw used in the calculation, measured in %. Starts at 10 % so you have a working example on load. Accepted range: 0–40 %.
Results
- Safe monthly paycheck
- 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.
- Average monthly surplus
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Tax to hold back / mo
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Annual salary to self
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
How does the irregular income budget calculator work?
Pay yourself a fixed salary from a variable business. This sets a safe monthly draw from your lowest recent months and shows the surplus to hold back. The underlying maths is: Draw = lowest month × (1 − tax set-aside) × (1 − safety margin).
What do I need to enter?
4 values: lowest month last year, average month, tax set-aside, and safety margin on draw. Each field starts with a sensible default, so you can change one number at a time and watch the result move.
What does the safe monthly paycheck 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). Irregular Income Budget Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/irregular-income-budget
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/irregular-income-budget" target="_blank" rel="noopener">Irregular Income Budget Calculator — RevenueLab</a> (2026).</p>
Source: [Irregular Income Budget Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/irregular-income-budget) (2026).