Self-assessment calculator
Self-assessment tax estimator
Use this calculator to get a rough idea of your income tax and National Insurance liability. It uses standard UK tax bands and simplified assumptions for a quick estimate.
What this estimate covers
The calculator uses your annual income, allowable expenses, and tax code to estimate a likely tax and National Insurance total. It is best used for planning and cashflow reminders.
- Income tax based on basic, higher, and additional rate thresholds.
- Class 2 and Class 4 National Insurance using typical thresholds.
- Personal allowance derived from the digits in your tax code.
Keep in mind
Your actual liability depends on reliefs, pension contributions, student loans, and other factors. Jeremy can provide the accurate calculation for your return.
Calculator
Self-assessment tax estimator
A quick estimate of income tax and National Insurance based on your annual profits.
Your inputs
Include expenses that are wholly and exclusively for business.
We estimate your personal allowance from the digits in your tax code. Complex codes may vary.
Snapshot
Estimated profit: £0.00
Taxable income: £0.00
Allowance used: £12,570.00
Effective tax rate: 0.00%
Estimated results
Calculated locally in your browser only.
Estimated total
£0.00
Based on current UK tax bands and a standard tax code.
Assumptions used
- Personal allowance derived from tax code (digits × 10).
- Basic rate 20% up to £37,700 of taxable income.
- Higher rate 40% to £125,140, then 45% thereafter.
- Class 2 NI at £3.45/week when profits exceed £12,570.
- Class 4 NI at 9% between £12,570–£50,270, then 2% above.
Important note
These calculators provide indicative estimates only and do not replace professional advice. Rates and thresholds can change, and your circumstances may affect the outcome. Please speak with Jeremy before making decisions.