Tools

Marriage Tax & W-4 Optimizer

Getting married changes your taxes immediately. See your marriage bonus or penalty, then get a specific W-4 action plan for both partners.

How this works

Filing comparison uses 2026 IRS brackets and standard deductions: $32,200 for MFJ, $16,100 for MFS. The marriage penalty or bonus is the difference in total tax between the two filing statuses.

Self-employment tax is calculated as net profit × 92.35% × 15.3%. The deductible half reduces your federal taxable income before brackets are applied.

Capital gains are taxed at preferential rates (0%, 15%, or 20%) stacked on top of ordinary income. The bracket shown reflects where your LTCG and qualified dividends fall in the income stack under each filing status.

W-4 withholding is allocated proportionally by wage share. Each partner's employer withholds as if their salary is the only income. The Step 4c recommendation closes the gap between allocated liability and projected withholding.

Community property states (AZ, CA, ID, LA, NV, NM, TX, WA, WI) have income-splitting rules for MFS that are not modeled here. State tax uses single-filer brackets for both MFJ and MFS (v1 limitation). Planning estimate only.