About Tax Trap Calculator
Empowering UK taxpayers with the knowledge and tools to understand their real tax position
Why We Built This
Tax Trap Calculator was built by a UK-based software engineer who discovered the 60% tax trap the hard way — by receiving their first salary above £100,000 and being stunned at how little of a pay rise actually reached their bank account.
After spending hours trying to understand why, and finding that every existing calculator either ignored the Personal Allowance taper entirely or buried it in jargon, the decision was simple: build a better one.
Tax Trap Calculator launched in early 2025 with a single goal — to give UK earners a clear, visual, and honest picture of how their income is really taxed. Since then it has expanded to cover pension salary sacrifice, the High Income Child Benefit Charge, multi-year tax comparisons, and bonus analysis.
Our Mission
The UK tax system contains several hidden traps — effective marginal rates that surge well above the headline figures most people know. The 60% trap between £100k and £125,140 is the most notorious, but it's far from alone. The High Income Child Benefit Charge creates similar cliff edges for families earning over £60,000, and the tapered pension annual allowance catches many very high earners by surprise.
Our mission is to demystify these traps with clear explanations, worked examples, and an interactive calculator that lets you model your own situation before making decisions about pension contributions, salary negotiations, or bonus timing.
What We Provide
Free Tax Calculator
Interactive salary calculator covering income tax, National Insurance, pension salary sacrifice, dividends, the HICBC, and bonus analysis. Supports 2023/24, 2024/25, and 2025/26 tax years. Scottish tax rates are fully supported.
Educational Guides
In-depth, plain-English guides on the 60% tax trap, pension salary sacrifice, the High Income Child Benefit Charge, and the UK tax system fundamentals — all cross-referenced with official HMRC sources.
Our Approach
Evidence-Based
All tax calculations are based on official HMRC rates, thresholds, and publicly available UK tax legislation. We link to primary sources (gov.uk income tax rates ) throughout our guides.
Privacy-First
Your salary and financial data are never stored on our servers. Calculations happen locally in your browser or via temporary, anonymous API calls that are not linked to any identifier. Data disappears the moment you close the page.
Kept Up-to-Date
Tax rates change with every Budget. We update the calculator and all guide content promptly after each HMRC announcement to ensure the figures you see are always current for the active tax year.
Transparent & Free
This tool is completely free to use with no sign-up required. We are supported by non-intrusive advertising via Google AdSense to cover hosting and ongoing development costs.
Important Disclaimer
We are not qualified financial advisors or accountants. This website is for educational and informational purposes only. All content is written based on publicly available HMRC guidance and UK tax legislation.
While we strive for accuracy, your personal tax situation may involve factors our calculator cannot model. Always verify important decisions with HMRC directly or consult a qualified tax professional (e.g., a Chartered Accountant registered with the ICAEW or CIOT).
Who We Help
Tax Trap Calculator is designed for UK taxpayers at all income levels, with particular focus on:
- •Higher earners (£50k–£150k+) navigating the Personal Allowance taper, marginal rate spikes, and pension decisions
- •Families affected by the High Income Child Benefit Charge and the £60k–£80k effective tax rate on Child Benefit
- •Employees considering pension salary sacrifice and wanting to understand the real cost-benefit before committing
- •Job seekers and professionals comparing salary offers and understanding true take-home pay differences
- •Anyone who wants a clear, honest view of their tax position without jargon or hidden complexity
Supporting This Resource
Creating and maintaining accurate tax calculators is a significant ongoing effort — every Budget requires careful updates across the calculation engine, all guide content, and every worked example. To keep this tool free and accessible to everyone, we display non-intrusive advertising via Google AdSense.
By using our site, you directly support the continued development of free educational tax resources for the UK community. Thank you for visiting.
Get In Touch
Found an error? Have a suggestion for a new feature or guide topic? We'd love to hear from you.
Contact Us