Income breakdown
Sales, other trading income, property income, interest and chargeable gains.
2026/27 rates · planning estimate
Corporation Tax calculator
Build a practical estimate from company income, allowable expenses, capital allowances and losses.
Instant tax estimateMarginal relief includedAssociated-company limits
Company income
£
Company turnover excluding VAT.
£
£
£
£
Taxable gain after applicable acquisition and disposal costs.
Allowable business costs
£
£
£
£
£
Only include costs incurred wholly for business purposes. Client entertaining, fines, dividends and most capital purchases are not deductible here.
Allowances, losses and thresholds
£
Use the tax allowance, not accounting depreciation.
£
Only enter losses available against this period's profits.
£
Usually dividends from unrelated companies that count in augmented profits.
months
HMRC reduces the rate thresholds for periods shorter than 12 months.
Enter companies under common control, excluding this company. The profit limits are divided by the total number including this company.
Estimated Corporation Tax
£13,475.00
Planning estimate for this accounting period
Taxable profit
£65,000
Effective rate
20.73%
Monthly reserve
£1,123
Marginal relief band
The 25% calculation is reduced by marginal relief, producing a gradual effective rate.
Marginal relief
£2,775.00
Profit calculation
Total company income£181,000.00
Less allowable business costs-£113,000.00
Profit before allowances£68,000.00
Less capital allowances-£3,000.00
Less losses claimed-£0.00
Estimated taxable profit£65,000.00
Adjusted thresholds used
Small profits limit
£50,000
Main rate limit
£250,000
Estimate only — this does not file a CT600
R&D relief, Patent Box, creative reliefs, group relief, foreign tax, loan relationships, ring-fence profits and loss restrictions need a full tax computation.
Ask us to review the calculationWhat the estimate includes
The calculator starts with income rather than asking you to know the final accounting profit, then shows how everyday costs and selected reliefs lead to estimated taxable profit.
Allowable costs
Cost of sales, payroll, premises, professional fees, software and other business-only running costs.
Tax adjustments
Capital allowances, eligible losses and distributions relevant to augmented profits.
Adjusted rate limits
Short accounting periods and associated companies reduce the £50,000 and £250,000 thresholds.
Corporation Tax calculator FAQs
What Corporation Tax rates does this calculator use?
For non-ring-fence profits it uses the current 19% small profits rate up to the adjusted £50,000 limit, 25% above the adjusted £250,000 limit, and marginal relief between those limits.
Why does the calculator ask about associated companies?
HMRC divides the £50,000 and £250,000 profit thresholds by the total number of associated companies, including your own company. Common control and commercial interdependence can affect which companies count.
Are dividends a deductible company expense?
No. Dividends are paid from profits after Corporation Tax and should not be entered as an allowable business cost.
Does this submit a Company Tax Return to HMRC?
No. It is an indicative planning tool only and does not prepare or submit a CT600, statutory accounts or tax computation.
Want to understand the result?
Read the full guide to rates, deadlines and reliefs, or ask us to prepare the company tax computation.