How this estimator works

The calculator estimates UK self-employed tax from annual inputs using tax-year-specific rules.

Calculation flow

  1. Taxable profit = gross self-employed income - allowable expenses - pension allowance.
  2. Income tax is calculated against stored UK tax bands with personal allowance handling.
  3. Class 2 and Class 4 NI are estimated from your taxable self-employed profit.
  4. Student loan estimate is applied when a plan is selected.
  5. Total estimated tax/NI drives take-home and monthly set-aside guidance.

Important assumptions

  • This is for planning and cashflow, not filing.
  • Scotland mode applies Scottish non-savings bands only.
  • Interest/dividend treatment is still simplified for quick estimation.
  • Payment-on-account is shown as a planning estimate.