Self-Employed Bookkeeping Calculator
Sort your income and expenses into Schedule C categories and see net profit, total deductions and estimated tax for 2026.
Bookkeeping for a one-person business is really one question: what is left after real business costs? Enter your gross receipts and expenses by category below and the calculator builds your net profit the same way Schedule C does, then estimates the tax on it.
Schedule C, line by line
These fields follow Form 1040 Schedule C: gross receipts at the top, cost of goods sold in Part III, ordinary expenses in Part II, and vehicle mileage in Part IV. Fill in what applies and the net profit on line 31 is calculated for you.
Line 31 — Net profit
$46,150
Self-employment tax
$6,521
Quarterly payment
$2,716
Schedule C summary
Gross receipts (line 1)$58,000
Returns & COGS− $0
Gross profit (line 7)$58,000
Vehicle mileage (line 9)− $7,700
Other Part II expenses− $3,650
Home office (line 30)− $500
Net profit (line 31)$46,150
Tax flowing from line 31
Self-employment tax (Schedule SE)$6,521
Half of SE tax deducted− $3,260
Federal income tax$2,967
CA state tax (est.)$2,491
Total tax$11,979
Effective rate on receipts20.7%
Line 31 net profit carries to Schedule 1 and to Schedule SE. A loss can offset other income, but three loss years in five invites a hobby-loss challenge. Estimates only — not tax advice.
Frequently asked questions
- What bookkeeping does a self-employed person actually need?
- A record of every dollar in, every business dollar out sorted into Schedule C categories, a mileage log, and receipts or statements that back both. Cash-basis books updated monthly are enough for the vast majority of gig workers and freelancers.
- Do I need a separate business bank account?
- It is not legally required for a sole proprietor, but it is the single change that makes bookkeeping fast. One account for platform deposits and business spending turns categorising a year into an afternoon instead of a weekend.
- Cash basis or accrual?
- Almost every sole proprietor uses cash basis: income counts when it lands, expenses count when paid. Accrual matters mainly when you carry inventory or invoice large balances that cross year-end.
- How do bookkeeping categories map to the tax return?
- They map straight onto Schedule C lines — car and truck expenses, supplies, advertising, commissions and fees, insurance, office expense, and so on. Using those names all year means no translation step in April.
- Are bookkeeping software and accounting fees deductible?
- Yes. Subscriptions, spreadsheet tools, tax software and fees paid to a preparer for the business portion of your return are ordinary business expenses on Schedule C.
- How often should I reconcile?
- Monthly. Reconciling once a month catches missing platform payouts and miscategorised spending while you still remember what a charge was, and it keeps your quarterly estimated payments based on real numbers.
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Related blog posts
- The Best Tax Deductions for Gig Workers in 2026The 15 best tax deductions for gig workers in 2026 — mileage, phone, home office, health insurance, retirement, and more. With examples and IRS rules.
- The Gig Economy Tax Guide for the USA (2026)Complete 2026 US gig economy tax guide — 1099 forms, Schedule C, SE tax, quarterly payments, deductions, and state rules for every gig platform.
- 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.
- Cell Phone Deduction for the Self-Employed: 2026 Rules, Methods, and RecordsHow self-employed filers deduct a cell phone in 2026 — business-use percentage, the device vs. the plan, Section 179, and audit-proof documentation.