UK corporation tax calculator
Estimate Corporation Tax on taxable profit for 2026/27. It applies the main rate, small profits rate and marginal relief in the £50k–£250k band.
How is UK corporation tax calculated?
Corporation tax is charged on the taxable profit of a UK limited company. For 2026/27 the main rate is 25% (profits above £250,000), the small profits rate is 19% (profits up to £50,000), and marginal relief tapers the effective rate between those bands using the formula (Upper limit − Profit) × Marginal Relief Fraction (3/200). The profit limits are divided by the number of associated companies. The return (CT600) is due 12 months after the accounting period end; tax is payable 9 months and 1 day after the period end.
Check the current GOV.UK Corporation Tax rates and associated-company rules. This tool estimates the tax from taxable profit; it does not complete a CT600.
Company Setup
Taxable profit
Enter an estimate of taxable profit after allowable business expenses and accounting adjustments, but before Corporation Tax. This calculator does not work out taxable profit from turnover, payroll, capital allowances or pension contributions.
Profit Extraction (Optional)
This helps illustrate how much profit may remain after a planned dividend. It does not affect Corporation Tax or calculate personal dividend tax.
Estimated Corporation Tax
£22,750.00
Based on the inputs selected, this is the estimated corporation tax due on taxable profits of £100,000.00.
Taxable Profit Entered
£100,000.00
Losses Applied
£0.00
Taxable Profit
£100,000.00
Corporation Tax
£22,750.00
Profit After Tax
£77,250.00
Effective Tax Rate
22.75%
Estimated Profit After Tax
£77,250.00
77.3% retained
Profit Breakdown
Insight
Your taxable profit falls within the marginal relief band. The effective rate of 22.75% reflects a blend between the 19% small profits rate and the 25% main rate.
Dividends are paid from post-tax profits. The figure shown is not a confirmation that a dividend is lawful or that the company has distributable reserves.
For tailored tax planning advice, speak with RR Accountants.
Disclaimer: This calculator provides a general estimate for planning only. It uses the taxable-profit estimate you enter and does not prepare a CT600 or determine your actual taxable profit, distributable reserves or personal dividend tax.
Need help planning profit, tax, or dividends?
Company tax is only one part of the picture. RR Accountants helps business owners manage corporation tax, dividends, bookkeeping, payroll, VAT, and year-end accounts with a joined-up approach.
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What this calculator helps you understand
Corporation Tax Estimate
See the estimated tax due on company profits based on the selected assumptions.
Post-Tax Profit
Understand how much profit remains in the business after corporation tax.
Post-dividend context
See the estimate remaining after a planned dividend, before personal dividend tax.
Business Planning Context
Turn a quick estimate into a broader tax and profit planning conversation.
This calculator provides an estimate for planning. For Corporation Tax, dividends, allowances and structure decisions, review our limited company accountants service or speak with RR Accountants.
Frequently Asked Questions
Need help with company tax, year-end accounts, or profit planning?
RR Accountants supports UK companies with bookkeeping, payroll, VAT, corporation tax planning, year-end accounts, director Self Assessment, and ongoing financial advice.