Contractor Calculator

Welcome to ContractorCalculator, the UK's leading website for contractors and freelancers. We've been online and independent since 1999, when we launched ir35calc.co.uk to help contractors count the cost of the then newly released IR35 tax legislation. Still owned by founder and former IT contractor Dave Chaplin, the site has grown dramatically since then to become the expert guide to contracting.

Dave is still actively involved in its management, supported by a dedicated team of contractors and freelancers. Our ABC-audited monthly audience of regular readers is made up of contractors, freelancers, interims and consultants from the IT, telecoms, engineering, oil, gas and energy, business, marketing and medical sectors.