Home / Sole trader expenses
The calculator starts with profit, not turnover. That means expense quality matters before any tax formula kicks in.
A sole trader pays tax on profit after allowable business expenses, not on gross revenue. If your expense records are weak, every later estimate is weak too.
Typical allowable costs include accountancy fees, software, travel for business, insurance, phone or broadband used for work, and a business proportion of some home running costs.
Work out a realistic annual profit figure first, then feed that into the calculator. If you only know revenue, deduct a sensible expense estimate before relying on the result.
If you are comparing whether to stay sole trader or incorporate, use the same profit assumption on both sites so the comparison is fair.
The homepage calculator is the fastest way to turn this guidance into a concrete monthly take-home and tax reserve estimate.
Profit. The calculator is built around taxable profit after allowable business expenses.