Modulas

IR35 calculator for 2026/27: inside and outside

At £500 a day, you take home about £74,637 a year inside IR35 and £72,765 outside it, through a limited company. Inside IR35, about £479 a day takes home the same as £500 a day outside. This is with the agency paying employer's National Insurance on top of your rate, as most do.

Worked out with the Modulas calculator, using HMRC rates for 2026/27. Rates checked against GOV.UK on 8 October 2026.

Work out your own figures

Take-home from £300 to £1,000 a day

Day rateInside IR35Outside IR35Inside leaves
£300£50,925£50,854£71 more
£400£64,381£61,810£2,571 more
£500£74,637£72,765£1,872 more
£600£85,562£81,796£3,766 more
£700£97,858£89,004£8,854 more
£800£110,154£99,346£10,808 more
£900£122,450£109,688£12,762 more
£1,000£134,746£120,030£14,716 more

Tax at the rates for England, Wales and Northern Ireland. Each setup's page has the Scottish figures.

How it's worked out

  1. IR35 decides whether a contract is taxed like a job.
  2. Inside IR35, you're paid through payroll on your day rate: income tax and National Insurance come off it, as for an employee. Here the agency pays employer's National Insurance on top of your rate.
  3. Outside IR35, you can work through your own limited company. It pays corporation tax on its profit, and pays you a small salary and the rest as dividends.

What it leaves out

  • Pension payments, business costs and student loan, unless you add them in the calculator.
  • Tax at the rates for England, Wales and Northern Ireland. Scotland has its own income tax bands: choose Scotland in the calculator.
  • Anything about your own situation, such as other income or savings.

Sources

Rates checked against GOV.UK on 8 October 2026.

To quote this page

Modulas, 'IR35 calculator for 2026/27: inside and outside', https://modulas.io/ir35-calculator/. HMRC rates for 2026/27, checked against GOV.UK on 8 October 2026.

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Questions

What is IR35?
The rules that decide whether a contract is taxed like a job. If it is, the contract is inside IR35 and you're taxed through payroll, much like an employee.
How much does inside IR35 change at £500 a day?
£74,637 a year inside IR35 and £72,765 outside it, a difference of £1,872 a year.
What day rate inside IR35 matches £500 a day outside?
Inside IR35, about £479 a day takes home the same as £500 a day outside.
Who pays employer's National Insurance inside IR35?
Here the agency pays it on top of your day rate, which is usual. Some agencies take it from your rate instead, which leaves you less. You can choose either in the calculator.
Who decides whether a contract is inside IR35?
For most medium and large clients, the client decides and tells you. For a small client, you decide. HMRC's Check employment status for tax tool can help.
How many working days does it assume?
232 working days: 5 days a week for a year, less 28 days off for holidays and bank holidays.
Does it work in Scotland?
Yes. Choose Scotland in the calculator and it uses Scotland's income tax bands. National Insurance is the same across the UK.
Is it free?
Yes. The calculator and every page like this are free, with no sign-up and no advertising.

Estimates, not financial advice, using HMRC rates for 2026/27. Talk to a qualified accountant before you act on them.