Business tax calculator
Corporation Tax calculator
Important: This guide provides general information, not personalised financial advice. Financial products, rates and eligibility rules can change, so check the provider’s current terms before applying.
Last updated: .
Estimate Corporation Tax on your company’s taxable profits, including Marginal Relief between £50,000 and £250,000.
Illustrative only, not financial or tax advice. Results depend entirely on the figures you enter. Figures filled in below are labelled “Example figure” — they aren’t recommendations.
Estimate Corporation Tax
Your illustrative results
- Corporation Tax
- –
- Effective rate
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- Marginal Relief
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- Limits used
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- Profit after tax
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After any Marginal Relief.
Tax ÷ profits × 100.
Reduction from the 25% main rate.
Lower and upper limits after adjustments.
Profits minus Corporation Tax.
How this calculator works
The calculator assumes one financial year’s rates apply to the whole period and that your company has no exempt distributions (so augmented profits equal taxable profits). It doesn’t cover ring fence profits or close investment-holding companies.
For an official check, use HMRC’s Marginal Relief calculator. Results are rounded to the penny.
The formulas we use
Limits: lower = £50,000 × months ÷ 12 ÷ (associated companies + 1); upper uses £250,000 the same way.
Profits at or below the lower limit: 19% × profits. Above the upper limit: 25% × profits.
In between: 25% × profits − Marginal Relief, where Marginal Relief = 3/200 × (upper − A) × (N ÷ A). We assume augmented profits (A) equal taxable profits (N).
Corporation Tax rates
| Profits | Rate |
|---|---|
| £50,000 or less | 19% (small profits rate) |
| £50,001 to £250,000 | 25% less Marginal Relief (standard fraction 3/200) |
| Over £250,000 | 25% (main rate) |
Sources: GOV.UK Corporation Tax rates and HMRC Company Taxation Manual CTM03925, checked 4 October 2026. Limits are reduced for short accounting periods and associated companies.
FAQ
What rate of Corporation Tax will my company pay?
19% on profits of £50,000 or less, 25% on profits over £250,000, and 25% less Marginal Relief in between, as of 4 October 2026.
What are associated companies?
Companies under common control. Each one reduces the limits — with 3 associated companies, the limits are divided by 4.
Does a short accounting period change the limits?
Yes, they’re reduced proportionately.
Is this the same as HMRC’s calculation?
It follows HMRC’s formula, but assumes no exempt distributions. Use HMRC’s calculator to confirm.
Does this calculator store my figures?
No.
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