Methodology

Rates are read from sites/selfemployed-tax/src/data.js, dated October 10, 2026. Brackets, the standard deduction, the 92.35% factor, the $184,500.00 Social Security wage base, the safe-harbor percentages, and the four due dates follow Form 1040-ES for 2026. The home-office simplified option is $5 per square foot, maximum 300 square feet, from the IRS page linked below.

Worked example

Single filer, $80,000.00 of net profit, no W-2 wages, no other income, simplified QBI on. Net earnings $73,880.00. Self-employment tax $11,303.64. Deductible half $5,651.82. QBI deduction $11,649.64. Income tax $5,343.82. Federal total $16,647.46. The same inputs are a unit test.

Left out on purpose

• The 2026 IRS standard mileage rate. No DoorDash or mileage page until that rate is in the file.
• 2026 Solo 401(k) and SEP contribution limits.
• The current underpayment interest rate, so there is no Form 2210 calculator.
• QBI wage and specified-service thresholds. The 20% line is the simplified deduction only.
• BLS wages for reasonable compensation. The salary page does not invent a median.
• State income tax, state LLC fees, and state estimated-tax dates.

Updated October 10, 2026. Tax year 2026.