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Irregular income budget

What baseline budget fits income that changes month to month?

Your numbers

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Baseline monthly budget

$4,866

Average income$5,725
Lowest month$3,900

Tip. Pay yourself the baseline every month and route the surplus to taxes and reserves first.

Assumptions

  • Baseline = average of the four months × (1 − buffer%).
  • Use baseline as a conservative monthly spending ceiling.

Explore the numbers

Examples and charts

Start with a scenario, then read the response curve to see which input actually moves the answer.

Example 1

Freelance swings

Wide month-to-month variance, which is where the buffer earns its keep.

Baseline monthly budget

$4,866

Example 2

Salary plus commission

A stable base with a variable top-up, so a smaller buffer is defensible.

Baseline monthly budget

$5,288

Example 3

Seasonal business

Two strong months carrying two lean ones, with a heavy buffer.

Baseline monthly budget

$4,219

Sweeps buffer percent from half to one and a half times your value, holding everything else fixed.

Response curve

How buffer percent moves the result

Baseline monthly budget

$4,866

$4.4k$4.6k$4.8k$5.0k$5.2k10%15%20%
Chart axis: Buffer percentNow 15% → $4.9k

What this calculates

Builds a conservative monthly spending ceiling from recent income months, then applies a buffer so a strong month does not set the lifestyle floor.

How to use it

  1. Start with month 1 income and work down the form, or load an example to begin from a realistic case.
  2. Read the headline result alongside the supporting rows, which show the intermediate figures behind it.
  3. Check the assumptions. They decide what the number includes and, more importantly, what it leaves out.
  4. Sweep buffer percent on the response curve to see how much it actually moves the answer.
  5. Run a cautious case as well as an optimistic one before using the estimate in a decision.

Common mistakes

  • Skipping a tax reserve on 1099 income.
  • Using four unusually good months as the sample.
  • Raising the baseline after one strong quarter instead of waiting for a full cycle.

Formula

Baseline = average of the months entered × (1 − buffer%)

Inputs

  • Month 1 income
  • Month 2 income
  • Month 3 income
  • Month 4 income
  • Buffer percent (%)

FAQ

Why not budget to the highest month?

That locks in commitments you cannot fund in a slow month, and slow months are the ones that arrive without warning.

How big should the buffer be?

The wider your income swings, the larger it should be. Compare the baseline against your lowest month: if the baseline is above it, the buffer is too thin.

Where does the surplus go in a strong month?

Tax reserve first if you are self-employed, then the emergency fund, then goals. The self-employment tax reserve calculator sizes the first bucket.

Are these numbers financial advice?

No. They are educational estimates based on the inputs and assumptions on this page. Confirm important decisions with a qualified professional and your own documents.

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