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IR35 Calculator

IR35 legislation, also known as off-payroll working, was introduced to identify 'disguised employees' and ensure they pay the correct tax like employees. Whether your contract falls inside or outside IR35 can significantly impact your take-home pay. Our IR35 calculator is designed for contractors who want to assess the financial impact of IR35 on their net income.

Use this free IR35 calculator to compare your take-home pay inside vs outside IR35 with instant results. Updated with the latest 2026/27 tax year figures.

Calculations last reviewed: 26th April 2026

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IR35 Calculation Example

Calculator Inputs Day rate: £200
Billable days: 220
Total revenue = £44,000
Annual Expenses: £10,000
Pension Contributions: £3,000
Annual Gross Salary: £20,000
This example shows exactly how the calculator arrives at each number. Click the “See how this was worked out” links under each line for the step-by-step calculation.
Results Summary Inside IR35 Outside IR35 Difference
Personal Taxes
See how this was worked out

Inside: Based on £20,000 salary → after £12,570 allowance, £7,430 is taxable → Income tax + employee NIC = £3,675.18.

Outside: Salary + dividend mix taxed → total personal taxes = £2,656.81.

£3,675.18 £2,656.81 £-1,018.38
Corporation Tax
See how this was worked out

Inside: All income taxed as employment → no company profit left → not applicable.

Outside: Company profit after expenses/pension → corporation tax at 19% = £1,662.50.

N/A £1,662.50 £1,662.50
Employer's NIC
See how this was worked out

Inside: Employer’s NIC due on £20,000 salary → £3,104.35.

Outside: Employer’s NIC calculated differently → £2,250.00.

£3,104.35 £2,250.00 £-854.35
Total Taxes
See how this was worked out

Inside: Personal tax (£3,675.18) + Employer’s NIC (£3,104.35) = £6,779.53.

Outside: Personal tax (£2,656.81) + Corporation tax (£1,662.50) + Employer’s NIC (£2,250.00) = £6,569.31.

£6,779.53 £6,569.31 £-210.22
Annual Net Income
See how this was worked out

Inside: After all taxes and NIC → take-home = £22,020.47.

Outside: After corporation tax, personal tax and NIC → take-home = £24,430.69.

Difference: Outside gives £2,410.22 more.

£22,020.47 £24,430.69 £2,410.22
Monthly Net Income
See how this was worked out

Annual net income ÷ 12 months.

Inside: £22,020.47 ÷ 12 = £1,835.04.

Outside: £24,430.69 ÷ 12 = £2,035.89.

£1,835.04 £2,035.89 £200.85
Tax % of Revenue
See how this was worked out

Total taxes ÷ £44,000 revenue × 100.

Inside: £6,779.53 ÷ £44,000 = 15.41%.

Outside: £6,569.31 ÷ £44,000 = 14.93%.

15.41% 14.93% -0.48%

How the IR35 calculator works

Inside IR35

This calculation takes into account the PAYE income tax, National Insurance contributions, and other deductions typical for an employee. If your contract is considered inside IR35, you’ll see exactly how this affects your net pay.

Outside IR35

In this scenario, the calculator reflects the standard tax regime for contractors operating through their own limited company, factoring in corporation tax and dividend taxation. You’ll see a potential higher net income, assuming a genuine outside-IR35 working arrangement.

Compare Inside vs. Outside IR35 Income

By inputting details such as your contract rate, annual expenses, pension contributions, and salary, our calculator provides a side-by-side comparison, allowing you to clearly see the financial impact of being inside IR35 versus operating outside IR35. It highlights the difference in your take-home pay under each scenario.

Who can benefit from this calculator

  • Contractors and Freelancers
  • Gain a clear picture of how IR35 affects your bottom line, helping you plan your take-home pay and set the right contract rates.

  • Recruiters and Clients
  • Understand the cost implications when hiring contractors, ensuring everyone is aware of how IR35 may influence pay rates and overheads.

  • Accountants and Advisors
  • Provide clients with a quick reference to illustrate the financial implications of IR35, guiding them toward more thorough status reviews when needed.

Using our IR35 Calculator takes just a few minutes but could save you from unexpected costs down the line. With a clear inside vs. outside IR35 comparison, you’ll know exactly where you stand—and what steps to consider next.

Important considerations

Estimates Only:

Our calculator shows indicative figures based on the inputs you provide and assumed working patterns. Actual tax liabilities may vary with changing expenses, income levels, or legislative updates.

Not Formal Advice:

IR35 determination is nuanced. Always consult a qualified accountant, tax advisor, or specialist if you have concerns about compliance or contract wording.

Keep Up-to-Date:

Rates and thresholds for National Insurance, corporation tax, and income tax may change each tax year. Ensure the calculator or your inputs reflects current HMRC guidelines.

Calculations Reviewed by ✔ Verified
Xero Advisor Certified | ACCA Part-Qualified Accountant

Calculations on this page have been reviewed and verified to ensure accuracy and alignment with current UK tax regulations for the 2026 tax year.

Last reviewed: April 2026

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