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Marginal tax rate calculator
Estimate the Income Tax, National Insurance and student loan taken from the next £1,000 of salary.
Illustrative result
38.2% of the next £1,000 goes in deductions
2026 to 2027
- Deductions on the next £1,000
- £382.12
- Amount kept from that £1,000
- £617.88
- Income Tax rate on taxable pay now
- 20%
Assumptions
- The marginal figure is the change in deductions on an extra £1,000, expressed as a percentage of that £1,000.
- Around £100,000 the Personal Allowance taper can make the effective marginal Income Tax rate 60% before National Insurance.
- Student loan rounding can move this percentage slightly away from 9% plus the tax rate.
Questions
Why use £1,000 rather than £1?
Pay-period rounding, especially for student loans, is easier to see on £1,000 than on a single pound.
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Related calculators
Estimates only. Tax and repayment rules can change, and this is not financial, tax or pension advice.
38.2% of the next goes in deductions£1,000See breakdown