Self-Employed Write-Offs Calculator
Add every 2026 self-employed write-off — mileage, home office, phone, software, insurance, retirement — and see the combined tax each one saves.
Self-employment is taxed on profit, not revenue. Every documented write-off you enter here lowers both the 15.3% self-employment tax base and your income tax.
Your deductions
Stack every 1099 write-off — Schedule C plus above-the-line adjustments.
Total deductions
$15,450
Estimated tax saved
$4,819
Effective savings
31.2%
Deduction breakdown
Mileage (12,000 × $0.7)$8,400
Home office (simplified)$600
Schedule C total$10,050
Above-the-line (health + retirement)$5,400
SE tax reduction (14.13%)$1,420
Income tax reduction$3,399
Total tax saved$4,819
Schedule C deductions reduce both income tax and 15.3% SE tax. Above-the-line deductions cut income tax and AGI-based phaseouts. Estimates only — not tax advice.
Frequently asked questions
- What can I write off when self-employed?
- Anything ordinary and necessary for the work: mileage at $0.70 per mile in 2026, home office, phone and internet at business-use percentage, equipment, software, supplies, advertising, bank and platform fees, professional services, business insurance, education, plus health premiums and retirement as adjustments.
- Is there a limit on self-employed write-offs?
- There is no cap on legitimate business expenses. Specific rules apply to a few categories — meals are generally 50%, the simplified home office maxes at $1,500, and vehicle costs must follow either mileage or actual expenses, not both.
- Can I write off health insurance?
- Yes, if you are not eligible for a subsidized employer plan through yourself or a spouse. It is a Schedule 1 adjustment limited to your net self-employment income, and it reduces income tax but not self-employment tax.
- How do I write off a car I use for both business and personal trips?
- Track business miles and multiply by $0.70, or track total actual vehicle costs and claim the business-use percentage. Personal commuting miles never count for either method.
- Do write-offs help if I also have a W-2 job?
- Yes. Schedule C expenses reduce your self-employment profit, which lowers both your self-employment tax and the income tax on that side income, regardless of your W-2 wages.
- What records do I need for write-offs?
- Amount, date, and business purpose for each expense — bank and card statements from a dedicated business account handle most of it, plus a mileage log with dates, destinations, and purpose.
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- Schedule C Line-by-Line: The 2026 Guide for 1099 Gig WorkersEvery Schedule C line explained for 1099 gig workers in 2026 — with DoorDash, Uber, and freelance examples, plus the exact expense categories to use.