CalculatorCentral.uk

Tax Code Calculator UK

Enter your values below to get the result first, then scroll for the full explanation and guidance.

Step 1 • Add values

Use the calculator

Enter your values below to generate an instant result. You can update the inputs at any time to compare different scenarios.

Example: GBP 1,000 taxable pay under BR gives approximately GBP 200 Income Tax for this period; SD1 gives approximately GBP 420.

Results refresh instantly as values change.

Illustrative Income Tax on this period's pay

£200.00BR flat-code estimate, 2026/27

Illustrative Income Tax on this period's pay: £200.00 (BR flat-code estimate, 2026/27)

The selected code's fixed rate applies to all taxable pay entered for this one period. It does not establish your correct code or final annual tax.

Flat-code PAYE withholding

The selected code's fixed rate applies to all taxable pay entered for this one period. It does not establish your correct code or final annual tax.

Result snapshot

A quick visual read of the values behind this result.

Current-period taxable pay£1,000.00
Code appliedBR

Recommended next checks

  • →Compare your existing code with your HMRC notice and payslip. NI and any other payroll deductions are separate.
Current-period taxable pay
£1,000.00
Code applied
BR

Illustrative current-period Income Tax before exact HMRC payroll rounding or cumulative prior-period adjustments. No NI, pension or student-loan deduction.

Try different values to compare results.

Select the flat-rate PAYE code already shown on your payslip and enter this period's taxable pay. The result estimates Income Tax withheld from that source, not your final annual tax bill or the code HMRC should assign.

Restricted scope stated

Applicable period shown

Excluded claim or payroll factors disclosed

Table of Contents

5

About Tax Code Calculator UK

Tax Code Calculator UK helps you work through the main numbers for this topic quickly with a simple input flow and an instant result.

Use the calculator result as a practical starting point, then review the explanation and assumptions on the page if you want more context.

How flat-rate tax codes apply

BR and its Scottish or Welsh equivalent use 20%; D0 and D1 use 40% and 45% in England, Wales and Northern Ireland, while Scottish SD0, SD1, SD2 and SD3 use 21%, 42%, 45% and 48%. NT deducts no Income Tax. These codes do not allocate a Personal Allowance to this source.

Formula explained

Flat-code PAYE Income Tax estimate

Estimate 2026/27 Income Tax on one current pay period under an existing flat-rate BR, D0, D1, Scottish or Welsh PAYE code.

Formula

Illustrative period Income Tax = current taxable pay x selected flat tax-code rate

How the result is built

1Enter taxable pay for one period, not annual salary.
2Select the existing flat-rate code shown on the payslip.
3Apply its fixed rate to this pay; NI and final annual liability are separate.

Example

Example: GBP 1,000 taxable pay under BR gives approximately GBP 200 Income Tax for this period; SD1 gives approximately GBP 420.

Assumptions

  • Use only an existing flat-rate PAYE code assigned to this income source; the calculator does not choose a correct code.
  • 2026/27 current-period taxable pay and code rate only; HMRC payroll rounding and cumulative adjustments can differ.
  • Standard allowance codes, 0T, K codes and W1/M1 are not supported here. National Insurance and final annual liability are excluded.

Source basis

  • HMRC: Understanding employees' tax-code letters

Trust and notes

Assumptions and important notes

This calculator is designed to give a fast estimate using the method shown on the page. Results are most useful when your inputs are accurate and the tool matches your situation.

Use the result as guidance rather than a final diagnosis or professional decision. If the result could affect health, legal, financial, or compliance decisions, verify it with a qualified source where appropriate.

  • Use only an existing flat-rate PAYE code assigned to this income source; the calculator does not choose a correct code.
  • 2026/27 current-period taxable pay and code rate only; HMRC payroll rounding and cumulative adjustments can differ.
  • Standard allowance codes, 0T, K codes and W1/M1 are not supported here. National Insurance and final annual liability are excluded.

Method

Flat-code PAYE Income Tax estimate

Last reviewed

October 13, 2026