National Insurance & Self-Employment Calculators
Class 2, Class 4, Self Assessment, and payments on account — the NI and self-employment calculators every sole trader needs before filing.
7 tools in this category
- National Insurance Calculator
Class 1, 2, and 4 NI — for employees and the self-employed.
- Payment on Account Calculator
Work out your January and July Self Assessment advance payments based on last year's tax bill.
- Self Assessment Estimator
Estimate your Self Assessment tax bill before you file.
- Class 4 NI Calculator
Class 4 NI on self-employed profits — 6% between £12,570 and £50,270, then 2% above. Breakdown by band.
- Class 2 NI Calculator
Check your Class 2 NI position — treated as paid, automatic credits, or voluntary contributions to protect your State Pension.
- Allowable Expenses
Check which self-employed expenses you can deduct from your profits.
- CIS Deductions Calculator
Construction Industry Scheme deductions at 20% or 30%.