How Flux Estimates Your Taxes

Flux estimates taxes using your combined income from all sources — not source-by-source. Here's the general logic:

1. Pool your income. All W-2 and 1099 income is combined into one total before any tax calculation, since your actual tax bracket is based on your combined income, not any single job.
2. Apply self-employment tax. If you have 1099 income, a 15.3% self-employment tax is calculated on it first. Half of that is deducted from your taxable income, the same way it works on your actual tax return.
3. Subtract retirement contributions, if you've entered any in your tax profile — a SEP IRA or Solo 401(k) for self-employment income, and/or a Traditional IRA. See [[Adding Retirement Contributions to Your Tax Profile]] for how these work.
4. Apply federal brackets. Progressive federal tax brackets are applied to what's left after the standard deduction.
5. Apply state and local tax. Based on the state (and city, if applicable) you set in your tax profile.
6. Apply the child tax credit, if you have qualifying children under 17, which reduces your estimated federal tax directly.

Your estimate updates automatically any time you add a new source, log income, or change your tax profile — so the number you see is always based on your latest information. Keep in mind this is an estimate, not tax advice or a substitute for filing.