How much more do I take home outside IR35 at £850/day?
At £850/day over 220 billable days (£187,000 contract revenue), outside IR35 nets you £99,301 per year through a limited company, versus £97,463 per year inside IR35 via an umbrella. That is a difference of £1,838 per year (1.9% more), before accounting for accountancy fees you'd pay either way.