Schedule C Calculator

1. Enter Part I (Income): gross receipts from your business, returns/allowances, cost of goods sold (if you sell physical products), and any other business income.
2. Enter Part II (Expenses): every business expense category from the official Schedule C lines. Keep itemized records for each.
3. The calculator computes your gross income (Line 7), total expenses (Line 28), and net profit/loss (Line 31).
4. Self-employment tax is calculated: 15.3% × 92.35% × net profit. Half is deductible on Schedule 1.
5. Line 31 flows to your Form 1040 via Schedule 1, Line 3 — combining with your other income to compute total tax.

Schedule C is the IRS form sole proprietors and single-member LLC owners use to report business income and expenses. The math is straightforward but the supporting documentation requirements are extensive.

Gross Income = Gross Receipts − Returns − COGS + Other Income
Net Profit/Loss = Gross Income − Total Expenses

Self-Employment Tax = Net Profit × 0.9235 × 0.153
Deductible Half = SE Tax / 2 (above-the-line on Schedule 1, Line 15)

Example: Freelancer with $75,000 gross receipts and $10,800 in expenses.

• Gross income: $75,000
• Total expenses: $10,800
• Net profit: $64,200
• SE tax = $64,200 × 0.9235 × 0.153 = $9,071
• Deductible half = $4,535 (goes on Schedule 1, Line 15)

Schedule C is one of the most-scrutinized parts of any tax return — the IRS sees it as a high-fraud-risk form. That said, legitimate self-employed taxpayers leave thousands of dollars on the table every year by not claiming deductions they're entitled to.

Three audit-risk patterns to avoid:

• Round numbers everywhere. If every expense is exactly $1,000 or $5,000, you're begging for an audit. Real expenses produce odd numbers. Document actuals.
• Schedule C losses 3+ years running. The "hobby loss rule" lets the IRS reclassify your business as a hobby if you show losses 3 of any 5 consecutive years. Hobby losses can't offset other income.
• Disproportionate deductions vs income. Expenses exceeding 75% of revenue draw automated scrutiny. Either reduce questionable deductions or have rock-solid documentation for everything.

For most self-employed people, hiring a CPA for $300-1,500 to prepare and review Schedule C pays for itself in caught deductions and reduced audit risk. Especially valuable in your first year of self-employment.