Tax Accountant Cardiff • Specialist tax advice for individuals, landlords and businesses

Personal, property and business estimates

UK Tax Calculators

Estimate Income Tax, Self Assessment payments, dividends, property profits, Capital Gains Tax, Corporation Tax, VAT, payroll deductions and selected HMRC penalties.

A calculator provides an initial figure from the information entered. It cannot establish whether the inputs are complete, which reliefs apply, whether another filing is connected or how HMRC will treat disputed facts.

Estimatenot a tax return or formal calculation
Tax yearmust match the period being reviewed
JurisdictionUK country and Welsh position may matter
Evidencerecords must support the eventual filing

Use estimates as a starting point

Choose the calculator by the figure you need—not by your job title

A landlord may need a rental-profit estimate and a separate gain calculation. A director may need personal dividend tax, company Corporation Tax and payroll figures. Keeping those calculations separate makes the result easier to check.

Personal income
Estimate tax on salary, self-employment, dividends or the Self Assessment balance.
Property
Estimate rental profit, finance-cost relief, a disposal gain or non-resident landlord tax.
Company
Estimate Corporation Tax, VAT, payroll deductions or salary and dividend outcomes.
HMRC deadline
Estimate a selected late-filing penalty before the actual notice and dates are reviewed.

Calculator directory

Tax calculators for individuals, landlords and businesses

Each link opens a dedicated tool. Check the tax year and assumptions shown on that calculator before using the result.

01

Income and annual filings

Personal tax calculators

02

Rental income and asset sales

Property and Capital Gains Tax calculators

03

Companies and employers

Business and company tax calculators

04

Dates and penalties

HMRC late-filing penalty calculator

Before relying on the result

A calculator only answers the question built into its inputs

If the question is incomplete, the result can still look precise while being wrong for the actual position.

Ask us to check an estimate

The tool may calculate

  • Tax using the selected year and bands
  • An estimate from the amounts entered
  • A comparison between defined scenarios
  • A total before rounding or filing adjustments

The tool may not establish

  • Whether all income and transactions were included
  • Residence, ownership or employment status
  • Eligibility for a relief, claim or election
  • Whether another return or deadline is connected

Cardiff and Welsh tax context

Check the jurisdiction as well as the tax year

A UK calculator may not cover every rule that differs by country or transaction type.

Income

Welsh taxpayer status

Welsh taxpayers are identified separately for Income Tax. Check the assumptions used by an income or dividend tool against the official Welsh Income Tax guidance.

Property purchase

Land Transaction Tax is separate

The rental-profit and Capital Gains Tax tools do not calculate purchase tax. Property transactions in Wales may involve Land Transaction Tax.

Asset sale

Rates depend on income and timing

A gain can cross tax bands, and rates or reliefs can change. Compare the tool’s tax year with the current Capital Gains Tax rates.

A useful calculation process

Move from an estimate to a supported figure

The result becomes reliable only when the inputs agree with the records and the correct tax treatment has been applied.

  1. 01

    Select

    Choose the calculator and tax year matching the event.

  2. 02

    Enter

    Use figures from the actual records rather than memory.

  3. 03

    Check

    Review assumptions, omitted income, ownership and relief conditions.

  4. 04

    File

    Prepare the required return or report from the supported calculation.

Need the result checked?

Ask us to review the figures and assumptions

Tell us which calculator you used, the tax year and what the estimate relates to. Do not send bank details, passwords or complete tax records through this enquiry form.

Common questions

UK tax calculator questions

Use the tool for an estimate and the supporting records for the actual return or advice.

Are the tax calculator results exact?

No. The result is an estimate based on the inputs and assumptions built into that calculator. The actual tax position may change because of omitted income, reliefs, ownership, residence, timing or another connected filing.

Which tax year should I select?

Select the year in which the income, gain, company period or filing obligation arose. The current UK tax year runs from 6 April 2026 to 5 April 2027, but an earlier return requires the rates and allowances for that earlier year.

Which calculators are useful for a landlord?

A landlord may use the Rental Profit Tax Calculator, Mortgage Interest Tax Relief Calculator, Non-Resident Landlord Tax Calculator and Capital Gains Tax Calculator. Rental income and a property disposal remain separate calculations.

Which calculators are useful for a company director?

A director may use the Dividend Tax Calculator, Salary vs Dividend Calculator, Corporation Tax Calculator and Payroll Tax Calculator. Company and personal tax results should be reviewed together but filed separately.

Does the property calculator include Welsh Land Transaction Tax?

No. The rental-profit and Capital Gains Tax tools shown here do not calculate the tax on purchasing Welsh property. Land Transaction Tax is a separate Welsh transaction tax.

Can I use a calculator result in a tax return?

Only after the inputs, tax year, treatment and supporting records have been checked. A calculator output is not itself evidence and does not replace the return, accounts or calculation schedule required for filing.

Can you check a result before I file?

Yes. Send the calculator name, tax year and a short explanation through the review form. We will identify the records and scope needed to check the calculation.