2026-27 · Corporation Tax
Corporation Tax Calculator
Small profits rate, marginal relief, and main rate — enter your taxable profit and see exactly what your company owes.
Taxable profit
After deducting salary, employer NI, expenses, and capital allowances
2026-27 thresholds
Corporation tax
£17,450
Effective rate
21.8%
Post-tax profit
£62,550
Breakdown
Marginal relief trap
Your profit sits in the marginal band. The effective rate on each extra pound earned here is 26.5% — higher than the main rate. Employer pension contributions or capital investment can reduce profits below £50,000 to benefit from 19%.
How it works
- 1
Calculate taxable profit
Start with accounting profit. Deduct allowable expenses: director salary, employer NI, pension contributions, business expenses, and capital allowances.
- 2
Apply the correct rate
Profits up to £50,000 → 19%. Profits £250,000+ → 25%. Between those, marginal relief reduces the bill.
- 3
Marginal relief formula
(3/200) × (£250,000 − taxable profit). Subtracted from tax at 25%. Creates an effective marginal rate of 26.5% in the band.
- 4
Plan around the band
If you're just above £50,000, employer pension contributions are the most efficient way to bring profit below the threshold.
HMRC sources
Disclaimer: For illustrative purposes only. Does not account for associated companies, R&D credits, losses carried forward, or other adjustments. Consult a qualified accountant before filing.
FAQs
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