Inside IR35
£74,423 annual cash
£121,848 cash-equivalent salary
UNDERSTAND YOUR NUMBERS
Contractor Working Days Calculator
Subtract leave, bank holidays, sickness, training and contract gaps from weekdays to estimate annual billable days.
Tax year 2026/27 · Last verified · Methodology · Official sources
Build your billable year
2026/27Your estimate
- Realistic billable days
- 220.0
- Non-billable weekdays
- 41.0
Planning estimate, not advice. Monetary examples use England, no other income or loans. No automatic levy, umbrella fee or pension charge is assumed. Outside IR35 uses £3,000 annual expenses; company tax assumes a full accounting year.
Worked example: £600/day
220 billable days give £132,000 revenue. These figures use the same engine as your comparison.
Outside IR35
£78,666 annual cash
£133,093 cash-equivalent salary
Make it yours
England, no loans or other income. Inside: assignment rate, no margin, levy or pension. Outside: £3,000 expenses, Personal Allowance salary, no pension or retained profit. Salary comparison: 5% employee and employer pension.
Compare with your salaryHow this calculation works
Count weekdays in the configured tax year, or enter your own available weekdays. Subtract non-overlapping unpaid days once; billable days cannot fall below zero.
Important assumptions
Enter regional bank holidays yourself. Do not count the same date as leave, a bank holiday and downtime.
Frequently asked questions
Should I assume 260 days?
Use actual weekdays as the starting point, then remove days you cannot invoice. 220 is an assumption, not a universal rule.
Can I invoice bank holidays?
Only if your contract pays for them. Otherwise exclude them.
Sources and review
Tax year 2026/27 · Last verified · Methodology · Official sources
- HMRC Income Tax, NI and student-loan thresholds
- HMRC dividend tax
- HMRC Corporation Tax and marginal relief
- HMRC pension tax relief
- HMRC off-payroll working guidance
- Government umbrella-company guidance
ContractorMoney.co.uk does not determine IR35 employment status. Use HMRC's official status guidance. Estimates only, not tax, financial, legal, accounting or investment advice. Read the limitations.