1099 deductions

These are categories, not a list of amounts. A deduction has to be ordinary and necessary for the business, and you need a record. Nothing below is a credit. Each one reduces the profit that the 1099 tax calculator starts from.

• Home office, simplified at $5 a square foot up to 300 square feet, if the space is used regularly and exclusively for business.
• Car expenses, either the IRS standard mileage rate or actual expenses for the same miles, not both. The 2026 mileage rate is not in this site's data file, so there is no mileage calculator yet.
• Self-employed health insurance premiums, not more than the net profit of the business. A plan an employer spouse provides can block the deduction. There is no calculator for that test here.
• Retirement contributions. The 2026 Solo 401(k) and SEP limits are not in the data file, so this site does not compute them.
• The deductible half of self-employment tax. This one does not reduce the profit. It reduces income tax.
• Supplies, software, advertising, contract labor, professional fees, business insurance, and bank fees.
• The business portion of a phone or internet bill. The personal portion stays personal.

State taxes, the QBI wage and specified-service limits, and the underpayment interest rate are also outside the data file. The homepage says so in the method note.