Self Assessment tax calculator
Use this calculator to calculate your Self Assessment position for the tax year. Enter your income, gains, reliefs, deductions and tax already paid to see the total tax due or overpaid.
Self employment or partnership income
Employment and pension income
Rental income
Savings and investment income
Other settings
Results
| Tax computation | Amount | |
|---|---|---|
| Total income | £0 | |
| Personal allowance | -£12,570 | |
| Taxable income | £0 | |
| Total income tax | £0 | |
| Tax payable | £0 |
How to use the Self Assessment tax calculator
Enter each income source for the tax year with any tax already deducted, then enter any other settings or tax reliefs that apply for the year.
Steps
- Start with self-employment or partnership profit and any CIS tax deducted.
- Open the employment and pension, rental, and savings sections to add the income sources that apply.
- Use other settings for Scottish residence, state pension age, student loans, Blind Person's Allowance, capital gains, pension contributions, Gift Aid, and the tax year.
- Review the results to see the tax payable or overpaid and the full tax computation.
Input notes
- Self employment or partnership income
- Use taxable profit for the tax year after allowable expenses.
- CIS tax deducted
- If you are a CIS subcontractor enter the total CIS tax already deducted from your pay.
- Employment and pension income
- Use gross taxable pay or pension income before PAYE tax. This is the figure on your P60.
- Employment or pension tax deducted
- Use the PAYE tax deducted from employment or pension income for the tax year. You can also find this on your P60.
- Benefits in kind
- Use the taxable value of benefits such as a company car or private medical insurance. If you have been given a P11D from your employer the value can be found on there.
- Rental income
- Use rental profit after allowable expenses but before residential finance costs e.g. mortgage interest.
- Residential finance costs
- Enter any residential property finance costs here such as mortgage interest.
- Rental tax deducted
- Enter any tax already deducted from rental income at source.
- Savings and dividends
- Use savings interest income and dividends outside ISAs.
- Tax year
- The default setting is the current 2026/27 tax year but you can change this to see the results for the previous two years. Tax bands, allowances, and national insurance thresholds can change by tax year, so check this setting if you want accurate figures for a previous year.
- Scottish residence
- Choose yes if Scottish income tax rates apply to your income. Scotland has different income tax rates and thresholds than the rest of the UK so make sure to select this option for accurate results if you are a Scottish tax payer.
- State Pension age
- Choose yes if you were over State Pension age for the tax year. The calculator removes Class 4 national insurance where this applies.
- Blind Person's Allowance
- Choose yes if you are eligible for Blind Person's Allowance. The calculator adds the allowance to your personal allowance.
- Student loan
- Choose yes if you have a student loan or postgraduate loan, then select each plan that applies.
- Capital gains
- Use taxable gains after losses have been applied but before the annual exempt amount.
- Personal pension contributions
- Enter relief-at-source pension payments you made personally. Put in the amount actually paid excluding any basic rate relief applied by the pension scheme.
- Gift Aid donations
- Enter the total amount you donated under Gift Aid for the year.
What the results mean
- Total tax shows the total due for the year before any tax deducted at source.
- Tax already paid shows the total tax already deducted through payroll or CIS.
- Tax payable is total tax less tax already paid. A negative figure indicates the inputs produce an estimated overpayment.
Common questions
Does this match the full HMRC Self Assessment calculation?
No. It is an estimate for common income types and reliefs. HMRC's calculation can include more adjustments, losses, payments on account, child benefit charge, marriage allowance, foreign income, and other boxes not included here.
Why are residential finance costs not deducted from rental profit?
For residential property, finance costs such as mortgage interest only attract basic rate tax relief and are handled as a separate basic rate reduction rather than deducted from rental profit.
How are pension and Gift Aid payments treated?
The calculator assumes the figures entered are the amounts actually paid, then grosses them up by basic rate relief. The grossed-up amount reduces adjusted net income and extends the basic and higher rate bands.
Do I include PAYE income on my Self Assessment tax return?
Yes, if you are completing a Self Assessment return you include employment income and pension income as well as self-employment, rental, savings, dividend or other income. Enter the gross pay or pension and the tax already deducted so the calculator can offset PAYE tax against the final estimate.
Does this include payments on account?
No. The calculator estimates the tax and deductions for the tax year, but it does not calculate payments on account, balancing payments, reductions to payments on account, interest or late payment penalties.
Does this include Class 2 national insurance?
No. It estimates Class 4 national insurance for self-employment profit where relevant, but it does not include voluntary Class 2 national insurance.
Can this calculator show a tax refund or overpayment?
Yes. If tax already deducted is higher than the tax payable, the tax payable figure can be negative. That indicates the inputs produce an estimated overpayment rather than an amount due.
Should I enter income before or after expenses?
For self-employment, partnership and rental income, enter taxable profit after allowable expenses. For employment, pension, savings, dividends and capital gains, enter the taxable amounts before tax deducted.
Assumptions
- Total tax payable includes income tax after residential finance cost reduction, capital gains tax, Class 4 national insurance, and student loan repayment where a loan plan is selected.
- Rental profit is treated as property profit after ordinary expenses but before restricted residential finance costs.
- Residential finance cost relief is estimated at 20% of the lower of finance costs, rental profit, and adjusted total income excluding savings and dividends, and it cannot create a refund.
- Personal pension contributions and Gift Aid donations are entered as amounts paid by the taxpayer and grossed up by 20% basic rate relief.
- Grossed-up pension and Gift Aid amounts reduce adjusted net income for the personal allowance taper and extend income tax and capital gains tax bands.
- Capital gains use the individual annual exempt amount and the 18% and 24% individual rates. The calculator does not model losses, Business Asset Disposal Relief, carried interest, trustee rates, or 2024/25 pre-30 October disposal timing.
- The calculator does not include payments on account, Marriage Allowance, High Income Child Benefit Charge, foreign income, losses, basis period transition profits, voluntary Class 2 national insurance, or property and trading allowances.
Source notes
- GOV.UK Income Tax rates and Personal AllowancesPersonal allowance, UK income tax rates, and allowance taper rules.
- Scottish Government income tax rates and bandsScottish non-savings, non-dividend income tax rates and bands.
- GOV.UK Tax on savings interestStarting rate for savings and Personal Savings Allowance rules.
- GOV.UK Tax on dividendsDividend allowance and dividend tax rates.
- GOV.UK Capital Gains Tax ratesIndividual capital gains tax rates and annual exempt amount examples.
- GOV.UK Tax relief for residential landlordsResidential finance cost basic rate tax reduction rules.
- GOV.UK Personal Allowances: adjusted net incomeAdjusted net income treatment for Gift Aid and pension contributions.
- GOV.UK Tell HMRC about a student loan in your tax returnSelf Assessment student loan repayment income rules.
- GOV.UK rates and allowances: National Insurance contributionsSelf-employed Class 4 National Insurance rates and thresholds.