How does the Corporation Tax Calculator determine the rate?

The calculator applies 19% up to £50,000 and 25% from £250,000, with marginal relief between those limits. Thresholds are divided by 1 + associated companies.

What are associated companies for Corporation Tax?

Companies under common control (including certain connected persons). The count adjusts the small-profits and upper thresholds.

Does it account for losses and capital allowances?

No. It provides a planning estimate focusing on headline rates, marginal relief and optional R&D adjustments.

Will the calculator auto-calculate?

No. It runs only when you press Calculate; after a short 3D animation the results are shown.

Can I export the Corporation Tax Calculator results?

You can copy the on-screen summary or request a PDF pack from our team.

Corporation Tax Calculator (UK)

Use this Corporation Tax Calculator to project your company’s tax charge. Enter taxable profits and the number of associated companies; optionally include R&D adjustments. Click Calculate to view the breakdown.

📌 Tip: Associated companies reduce the small-profits and upper limits.

Calculator inputs

Taxable profits before Corporation Tax (GBP)

Profits after allowable expenses/capital allowances but before Corporation Tax.

Associated companies

HMRC divides the £50k/£250k thresholds by 1 + associates.

Advanced: R&D adjustments (optional)

R&D (SME additional deduction 86%) — qualifying spend

Adds an extra 86% deduction to model the legacy SME scheme.

RDEC — credit on qualifying costs

Illustrative only — treated as taxable income then credited back.

No auto-calc. The Corporation Tax Calculator runs after you click Calculate.

Results

Run the 3D sequence to generate your estimate.

How this Corporation Tax Calculator works

Our Corporation Tax Calculator applies the small profits rate of 19% up to £50,000 and the main rate of 25% from £250,000, with marginal relief tapering the rate in between. If your company has associated companies, the thresholds are divided by 1 + associates, which affects whether your profits fall into the small-profits rate, marginal band or main rate.

The advanced options help you assess R&D impact. The SME field adds an additional 86% deduction to qualifying costs. The RDEC fields model an above-the-line credit (simplified here by adding the credit to profits then netting it off). Use the figures for planning; for filing, request an advice call with our specialist team.

Corporation Tax Calculator FAQs

What counts as an associated company?

Companies under common control, including certain connected persons. The count is used to divide the small-profits and upper thresholds.

Does this calculator include losses or capital allowances timing?

No. It focuses on headline rates, marginal relief and optional R&D. Add losses and capital allowances in your management forecast or speak to us for a full computation.

Are the Corporation Tax rates current?

This tool reflects a typical UK setup (19%/25% with marginal relief). If HMRC updates the rules, we will refresh the calculator.

Will it auto-calculate?

No. The Corporation Tax Calculator runs only on click, then displays a clear breakdown.

Can I export or share the result?

Copy the summary from the results card or contact us for a PDF pack tailored to your year-end.