About the C Corporation Tax Calculator
This C corporation tax calculator follows a dollar of profit from the corporation to the shareholder. It applies your state corporate income tax, the flat 21% federal corporate rate on what remains, then the qualified dividend tax (0%, 15% or 20%), the 3.8% net investment income tax if it applies, and state income tax on whatever profit you pay out as dividends. The result is the combined “double taxation” rate and the cash that actually reaches the owner.
It is aimed at founders choosing between a C corp and an LLC or S corp, owners deciding how much profit to distribute versus retain, and accounting students studying double taxation. A side-by-side comparison estimates the income tax the same profit would bear if it passed straight through to you at your personal marginal rate, optionally reduced by the section 199A qualified business income deduction.
Figures reflect federal rules for the 2026 tax year: the 21% corporate rate has been flat since 2018 and qualified dividends are taxed at 0%, 15% or 20% depending on taxable income. The model ignores payroll and self-employment taxes, salaries paid to owner-employees, credits, the accumulated earnings tax and state-specific quirks, so treat the comparison as a first-pass estimate to discuss with a tax adviser.
With the default inputs, the total tax (corporate + dividend) is $101,480.00. Change any value above to recalculate instantly.
How to use the c corporation tax calculator
- 1Enter the corporation’s taxable income for the year.
- 2Enter your state’s corporate income tax rate (0 if none).
- 3Choose how much after-tax profit you will pay out as dividends.
- 4Pick your qualified dividend rate, NIIT status and state income tax rate.
- 5Enter your personal marginal rate to compare with a pass-through entity.
Formula and method
A C corporation is a separate taxpayer. It pays state corporate tax first; that tax is deductible, so the 21% federal rate applies to profit after state tax. Whatever the company distributes as dividends is taxed again in the shareholder’s hands — this second layer is what “double taxation” means. Qualified dividends use the long-term capital gains rates of 0%, 15% or 20% depending on taxable income, high earners may owe the 3.8% net investment income tax, and most states tax dividends as ordinary income.
The pass-through comparison taxes the whole profit once at the owner’s marginal federal rate, reduced by the QBI deduction percentage you enter, plus state income tax. It deliberately excludes self-employment and payroll taxes, owner salaries, credits and the timing benefit of retaining earnings, which can all change the answer.
- P
- Corporate taxable income
- s
- State corporate income tax rate
- q
- Qualified dividend rate (0%, 15% or 20%)
- s_ind
- Shareholder’s state income tax rate
- m
- Owner’s federal marginal income tax rate (pass-through case)
Worked examples
$250k profit, all paid out as dividends
State tax at 6% is $15,000; federal tax is 21% of the remaining $235,000, or $49,350. Paying out the $185,650 left as dividends costs another $37,130 at 15% federal plus 5% state, for total tax of $101,480 (40.6%). Passing through at 32% + 5% would cost $92,500.
$1M profit, half retained, top dividend bracket with NIIT
Federal corporate tax is $210,000. Paying half of the $790,000 after-tax profit as dividends triggers 23.8% shareholder tax ($94,010), while $395,000 is reinvested. Total tax of $304,010 is about $66,000 less than a 37% pass-through — the advantage of retaining earnings.
Small company, 0% dividend bracket vs pass-through with QBI
The corporation pays $21,000 and the owner’s dividends fall in the 0% bracket. As a pass-through, a 20% QBI deduction leaves $80,000 taxed at 22%, or $17,600 — about $3,400 less, before self-employment tax.
Frequently asked questions
What is the C corporation tax rate in 2026?+
The federal corporate income tax rate is a flat 21% of taxable income, as it has been for tax years beginning after December 31, 2017. Most states add their own corporate income tax, which is deductible when computing federal taxable income.
What is double taxation?+
A C corporation pays tax on its profit, and shareholders then pay tax again when that after-tax profit is distributed as dividends. With 21% corporate tax and a 15% dividend rate, the combined federal rate on distributed profit is about 32.85%, before state taxes and the NIIT.
How are C corp dividends taxed?+
Qualified dividends are taxed at 0%, 15% or 20% depending on the shareholder’s taxable income and filing status — for 2026 the 0% rate applies up to $49,450 of taxable income for single filers and $98,900 for joint filers, and the 20% rate starts above $545,500 (single) or $613,700 (joint). High earners may also owe the 3.8% net investment income tax.
Can a C corp avoid double taxation?+
Partly. Paying owner-employees a reasonable salary is deductible to the company, and retaining profits defers the second layer of tax. However, excessive retained earnings can trigger the accumulated earnings tax, and salaries carry payroll taxes.
Is a C corp or an S corp better for taxes?+
S corps and LLCs avoid the corporate layer of tax, which usually wins when owners take most profit out. C corps can come out ahead when large profits are reinvested, when owners are in the top personal brackets, or when qualified small business stock (Section 1202) treatment is expected on a sale.
Tax results are estimates based on published rules and simplified assumptions. They are not tax advice — check official guidance or a tax professional for your situation.