Corporation Tax calculator
Estimate your limited company’s Corporation Tax on its profit, including marginal relief between £50,000 and £250,000. 2025/26.
Assumes a single company with no associated companies and a 12-month accounting period. Associated companies and a short period change the thresholds, we’ll handle that for you.
In plain English
The terms, explained
New to this? Here’s what the words on this page actually mean.
- Corporation Tax
- The tax a limited company pays on its profits.
- Taxable profit
- Your profit after allowable business expenses, the figure the tax is based on.
- Marginal relief
- A sliding scale between £50,000 and £250,000 of profit, so the rate eases up gradually instead of jumping straight to 25%.
- Effective rate
- The actual percentage of your profit that goes in tax, once the rates and relief are applied.
FAQ
Corporation Tax calculator, your questions answered
How do I calculate Corporation Tax?
Apply the rate to your taxable profit: 19% up to £50,000, 25% over £250,000, and a tapered “marginal relief” rate in between. So most small companies pay somewhere between 19% and 25%. Our calculator works the taper out for you.
How much Corporation Tax will I pay on £100,000 profit?
For 2025/26, around £22,750, that’s the 25% main rate reduced by marginal relief, giving an effective rate of roughly 22.75%. Enter your own profit above for an instant estimate.
Is Corporation Tax 25% now?
Only on profits above £250,000. Below £50,000 the rate is 19%, and between the two a sliding marginal-relief rate applies, so the headline 25% only affects larger companies.
Is Corporation Tax based on turnover or profit?
On profit, your income after allowable business expenses, not turnover. The simplest way to reduce it is to make sure every allowable cost is claimed.
How can I reduce my Corporation Tax?
Claim all allowable expenses, capital allowances on equipment, employer pension contributions, and reliefs such as R&D tax credits where you qualify. Planning these properly is exactly what we do for our limited-company clients.
When is Corporation Tax due?
Payment is due nine months and one day after your accounting period ends, earlier than the return itself, which is due 12 months after the period end. We track both deadlines for you.
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