Useful next calculations
Rates and sources, 2026/27
UK Corporation Tax. Main rate 25% from Apr 2023; 19% small-profits rate for profits under £50k.
| Band or figure | Rate |
|---|---|
| Small-profits rate | 19% (profits ≤ £50,000) |
| Main rate | 25% (profits ≥ £250,000) |
| Marginal relief | £50,001 – £250,000 |
Source: HMRC — Corporation Tax rates. Source checked for 2026/27.
When to use this calculator
- Before accepting a pay change, bonus, pension contribution or salary-sacrifice option.
- When you want a simple take-home estimate before payroll or filing.
- When you are approaching the £100,000 income level and want to see the personal allowance taper.
- When you need to convert between hourly, monthly and annual pay.
Worked example: £100,000 taxable profits
Use these sample inputs as a quick scenario test, then change one variable at a time to compare outcomes.
| Input | Value |
|---|---|
| Taxable profit | £100,000 |
| £100,000 × 25% | £25,000 |
| Less Marginal Relief: (£250,000 − £100,000) × 3/200 | £2,250 |
| Corporation tax due | £22,750 |
| Effective rate | 22.75% |
Each extra £1 of profit between £50k–£250k costs 26.5p, not 25p — so timing investments to keep profits in the small-profits band can save real money.
How to read your results
Corporation Tax Due
Review this figure alongside your gross income so you can understand deductions before the tax year closes. It is a planning estimate, not a filed return.
Effective Rate
The effective rate lets you compare options on a like-for-like basis rather than being misled by different compounding periods or fee structures.
Method & assumptions
This calculator applies the corporation tax rates and thresholds in force from April 2023 as set by HMRC. It uses the small profits rate for companies below the lower threshold, the main rate for those above the upper threshold, and applies the marginal relief formula for profits in between. The accounting period is assumed to be a standard 12-month period.
The calculator works from taxable profit, which is your accounting profit adjusted for disallowable expenses, capital allowances, and other tax-specific adjustments — it does not derive taxable profit from raw turnover or receipts. Associated company rules, which reduce the applicable thresholds where common control exists, are not modelled here. The calculator also excludes ring-fenced profits, close investment holding companies, and banking surcharge provisions. For accurate filing, always use figures prepared by a qualified accountant or the HMRC Corporation Tax online service.
Common mistakes
- Entering gross income when you really want take-home pay, or vice versa.
- Ignoring pension contributions, deductions or local tax rules that change the result.
- Comparing monthly and annual figures without standardising them first.
- Overlooking National Insurance or student-loan plan differences that apply to you.
What to do next
- Check the same scenario with related pay or deduction calculators.
- Keep a copy of the assumptions so you can compare the next tax year or pay period.
- If you are self-employed, compare this result with the self-employment tax calculator.
- Check whether a small pension contribution change moves take-home pay more than you expect.
Guides that use this calculator
- UK Dividend Tax 2026/27: Rates, £500 Allowance & Director StrategyUK dividend tax guide — 10.75%/35.75%/39.35% rates for 2026/27, the £500 allowance, and how directors should mix salary and dividends after CT changes.
- UK Corporation Tax: 19%, 25% and the 26.5% Marginal Band ExplainedHow the post-April-2023 UK Corporation Tax structure works — Small Profits Rate, main rate, marginal relief, associated-company rules, filing deadlines and deductible costs.