The figure this rate applies to has already been adjusted
A 21% rate on $1,000,000 of taxable profit is $210,000, leaving $790,000. The important word is taxable: the figure tax is charged on differs from the profit in the accounts, sometimes substantially, because tax law and accounting standards disagree about timing and about what is deductible at all.
corporate tax = profit x rate (+ surcharge on the base tax)
The usual adjustments are depreciation, where tax rules prescribe their own schedule; entertainment and certain fines, which are disallowed entirely; provisions, which are often not deductible until the cost is actually incurred; and losses carried forward from earlier years. A company reporting a profit in its accounts and paying no tax is usually explained by one of these rather than by anything exotic.
Surcharges push it up; credits and allowances pull it down
The surcharge field exists because many systems add one — a percentage of the tax itself, sometimes tiered by profit level, which raises the effective rate above the headline. Several jurisdictions also apply a lower rate to smaller profits, so a single headline figure describes only part of the range.
In the other direction, research credits, capital allowances and incentives for particular activities reduce tax below the statutory rate. The effective rate reported here is tax over taxable profit; the rate that matters for comparison across companies is usually tax over accounting profit, which can be several points lower.
Profit distributed to owners is usually taxed again
The $790,000 retained is after corporate tax only. Distributing it as dividends generally triggers tax in the shareholder’s hands, so the combined burden on profit that reaches an owner is higher than the corporate rate alone — sometimes substantially, depending on how the jurisdiction integrates the two.
This is why comparing corporate tax rates across countries without looking at dividend taxation is misleading. Some systems deliberately offset one against the other through imputation credits or reduced dividend rates; others tax both fully. For an owner-managed company, the combined figure is the one that decides how profit should be extracted.
Tiers, minimum taxes, and where the profit was earned
Many systems apply tiered rates, alternative minimum taxes, or separate regimes for particular sectors. Several now apply a global minimum rate to large multinational groups regardless of where profit is booked. A flat rate against a single profit figure models none of that.
Jurisdiction matters as much as rate. Profit earned in more than one country is allocated by transfer pricing rules, taxed locally, and then subject to relief for double taxation that varies by treaty. For anything beyond a single-jurisdiction company, this calculation is a starting estimate and not a liability.
Frequently Asked Questions
What is the difference between the headline and effective rate?
The headline rate is the stated corporate rate. The effective rate here is the total tax, including surcharge, divided by taxable profit, so it is higher than the headline rate whenever a surcharge applies.
Is corporate tax charged before or after a dividend?
Corporate tax is charged on company profit first. Any dividend is paid from the after-tax profit and may then face its own dividend or withholding tax, which this calculator does not include.
What profit figure should I enter?
Enter taxable profit, the profit after the book-to-tax adjustments your country requires, not the simple accounting profit. Use the taxable-profit calculator first if you need to derive it.
Sources & References
Figures on this page are checked against primary, authoritative sources. Links open in a new tab.
Tax rules vary by country, state, tax year, filing status, income type, deductions, and exemptions. This calculator is educational and uses the values you enter. Always verify final tax treatment with official sources or a qualified tax professional.
Published the calculator with its formula, worked example, assumptions, limitations and a bespoke guide, and added an automated formula test suite covering it.
Verified that any surcharge raises the effective rate above the headline rate, and that after-tax profit always reconciles to profit less tax.
Frequently Asked Questions now show on the page: 3 answers, checked in a page-by-page audit.
What the calculation assumes and where it stops now show on the page.
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