Contractor & Freelancer Calculators

Contracting and freelancing in the UK involves a more complex set of tax calculations than straightforward employment. The question of how to structure your work — sole trader, limited company, umbrella, or agency PAYE — has a direct and often significant impact on your take-home pay. These calculators are designed to cut through the complexity and give you clear, numbers-first answers to the questions that matter most.

IR35 is the most consequential piece of legislation for UK contractors. If your engagement falls inside IR35, your contract income is treated as employment income and taxed accordingly — typically costing £8,000–£20,000 per year compared to an outside-IR35 limited company position at the same rate. The IR35 calculator shows the real pound difference so you can make informed decisions about rate negotiation and contract structure.

The Ltd vs sole trader comparison is the other foundational decision. At profit levels above £45,000–£50,000, incorporating typically produces a meaningful tax saving — but only after accounting for the higher accountancy costs a limited company incurs. Below that profit level, the administration often costs more than the saving. The calculator shows the exact crossover for your figures.

For construction workers, the CIS calculator shows your deduction position and helps estimate your Self Assessment refund if you are registered at the standard 20% rate. The allowable expenses checkercovers the full range of deductions available to sole traders and subcontractors.