Calculators
Rough answers in thirty seconds. Nothing is stored, nothing is emailed to you, and no address is required — the figures stay in your browser.
Corporation tax calculatorWhat your company actually pays, including marginal relief — and why every extra £1 between £50k and £250k costs 26.5%.Rental income tax calculatorThe tax on your rental profit, including the finance cost restriction — and what that restriction costs you.Dividend tax calculatorThe 2026/27 rates with the band split shown — and why your salary decides how much falls into the higher rate.IR35 calculatorTake-home inside versus outside at 2026/27 rates — and how small the gap has become.
Also on the site
These sit inside the pages they belong to, because the number only means something with the explanation next to it:
- Self-employed tax estimator — income tax and Class 4 National Insurance on your profit
- CIS refund estimator — what the deductions and your expenses are likely to produce
- Do I need to file a Self Assessment? — six triggers, checked in half a minute
- HMRC letter checker — identify the letter you have received
What they are, and are not
Every one applies current rates to the figures you type. None of them knows about your reliefs, your losses, your other income or the year you actually mean. They are a starting point for a conversation, not a substitute for the return — and we would rather say that plainly than let a screenshot of an estimate become a plan.