Business Profit Tax Calculator & Stock Tax Studio
Analyze net company earnings and equity trades with our business profit tax calculator. Features an integrated tax calculator for stocks to forecast capital gains, corporate obligations, and take-home profits.
Company Revenue & Expenses
P&L ModelCorporate Strategy with Business Profit Tax Calculator
Understanding the real bottom line requires factoring in state deductions and corporate tax entity tiers. Our business profit tax calculator empowers founders, entrepreneurs, and accountants to preview quarterly liabilities, optimize write-offs, and safeguard company capital reserves.
Tax Calculator for Stocks & Capital Gains
Holding stocks for 366 days instead of 364 days can mean the difference between ordinary income tax rates (up to 37%) and preferential long-term capital gains brackets (0% to 20%). Using our tax calculator for stocks helps investors strategically time trade exits to maximize retained wealth.
How Business Profit Is Taxed (US)
Taxable profit = revenue - deductible expenses. How that profit is taxed depends on your entity type:
| Entity | How profit is taxed | 2026 federal rate |
|---|---|---|
| Sole prop / LLC (default) | Pass-through to personal return + self-employment tax | 10-37% brackets + 15.3% SE tax |
| S corporation | Pass-through; owner salary subject to payroll tax | 10-37% brackets on distributions |
| C corporation | Flat corporate tax on profits | 21% flat |
Capital Gains: Short-Term vs Long-Term
Stock profits held over a year get preferential rates. The holding period is the single biggest lever on your stock tax bill:
| Holding period | Tax treatment | 2026 federal rates |
|---|---|---|
| 1 year or less (short-term) | Taxed as ordinary income | 10% - 37% |
| More than 1 year (long-term) | Preferential capital gains rates | 0%, 15% or 20% by income |
| Net capital losses | Offset gains; up to $3,000/yr vs ordinary income | Remainder carries forward |
Worked Examples
Tip: entity choice is a math problem: model your actual profit against pass-through brackets plus SE tax vs the 21% flat C-corp rate with double taxation on dividends. Revisit annually as profit grows.
Frequently Asked Questions
How do I calculate tax on business profit?
Subtract deductible expenses from revenue to get profit, then apply your entity's tax treatment: pass-through entities use personal brackets plus self-employment tax, while C-corps pay a flat 21% federal rate.
What is the US corporate tax rate in 2026?
21% flat at the federal level for C corporations. State corporate taxes add on top and vary widely.
How are stock profits taxed?
Stocks held over a year face long-term capital gains rates of 0%, 15% or 20%. Stocks held a year or less are taxed as ordinary income at 10-37%.
Can stock losses offset business profits or capital gains?
In US tax law, capital losses offset capital gains dollar-for-dollar. Up to $3,000 of net capital losses can also offset ordinary income per tax year, with remaining losses rolling forward indefinitely under tax-loss harvesting rules.
What is self-employment tax?
15.3% on net self-employment earnings (Social Security + Medicare) for sole proprietors and LLC members, on top of income tax. S-corps can reduce it by paying owner salary and taking the rest as distributions.
Should I be an LLC or S-corp for taxes?
LLCs default to pass-through with SE tax on all profit. S-corp election lets you split income into salary (payroll taxed) and distributions (not SE-taxed), which usually wins once profit exceeds roughly $60,000-$80,000.
What business expenses are tax deductible?
Ordinary and necessary costs: rent, supplies, software, contractor payments, business travel, home office (simplified or actual), health insurance premiums for the self-employed, and half of SE tax.
How do quarterly estimated taxes work?
If you will owe $1,000+ at filing, pay quarterly (Apr 15, Jun 15, Sep 15, Jan 15) to avoid underpayment penalties. Base each payment on the prior year safe harbor (100-110% of last year's tax) or current-year actuals.
What is tax-loss harvesting?
Selling losing investments to offset gains, then optionally rebuying after 30 days (wash-sale rule). It converts a paper loss into a real tax reduction without changing your portfolio much.
How long must I hold stock for long-term rates?
More than one year. Buy on Jan 1, 2025 and sell on Jan 2, 2026 or later for long-term treatment; selling on Dec 31, 2025 is short-term.
Are dividends taxed like stock gains?
Qualified dividends use the same 0%/15%/20% rates as long-term gains. Non-qualified dividends are taxed as ordinary income.
What is the wash-sale rule?
If you sell at a loss and buy a substantially identical security within 30 days before or after, the loss is disallowed for now (added to the new cost basis instead).
Do I pay tax on unrealized gains?
No. US federal tax applies when you sell (realize) the gain, not while the stock sits in your account going up.
How does this calculator handle state taxes?
It focuses on federal math. Add your state's income or corporate rate on top; nine states have no personal income tax at all.
Is this tax calculator financial advice?
No. It is an educational estimator. Tax law is complex and personal; consult a CPA or tax professional for decisions with real money.
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