Free UK Tax Calculator Widget, Embed on Your Site

<iframe src="https://calculatetax.uk/embed/calculator" width="100%" height="680" frameborder="0" title="UK Tax Calculator 2025-26, calculatetax.uk"></iframe>
<p style="font-size:13px;text-align:center;margin-top:6px">Free <a href="https://calculatetax.uk/">UK Tax Calculator</a> by calculatetax.uk</p>

Why embed a tax calculator?

Readers who land on finance, HR, or recruitment content often want a quick answer: "what will I actually take home?" If your article already covers salaries, contracts, or job offers, a built-in calculator keeps visitors engaged instead of bouncing to a separate tool. Pages with interactive elements tend to earn longer session times, and longer sessions correlate with better search performance.

Our widget runs the full 2025-26 UK tax engine in the browser. No server round-trips, no third-party tracking, no cookies. The user enters a gross salary and gets an instant breakdown of Income Tax, National Insurance, and net pay across four UK regions: England, Scotland, Wales, and Northern Ireland.

What the calculator covers

The embedded calculator handles all the main PAYE deductions for employed workers in the 2025-26 tax year.

• Income Tax across all bands from the Personal Allowance (0%) up to the Additional Rate (45% in England, 48% in Scotland).
• National Insurance at 8% between the Primary Threshold and the Upper Earnings Limit, and 2% above that.
• Student loan repayments on Plans 1, 2, 4, 5, and the Postgraduate Loan. Select the plan and see monthly deductions reflected immediately.
• Pension contributions via salary sacrifice. Move the slider from 0% to 40% and watch the impact on both take-home pay and total deductions.
• Scotland comparison. Scottish taxpayers face six income tax bands instead of three. The calculator can show an England-vs-Scotland side-by-side so readers understand the difference.

How to install the widget

Paste the iframe snippet above into any block that accepts raw HTML. On WordPress, use a Custom HTML block. On Squarespace, add a Code Block. On Webflow, use an Embed element. On a plain HTML page, just paste the code between your opening and closing body tags.

The default height of 680 pixels fits the calculator comfortably on desktop screens. If your layout is narrow or your readers are mostly on mobile, increase the height to 780 or 850 pixels so the full results table is visible without scrolling inside the iframe. The width is set to 100%, so it fills whatever container you place it in.

The widget adapts to light and dark backgrounds automatically. It reads the visitor's stored theme preference and renders accordingly. If your site uses a dark theme, your readers will see a dark calculator. Light-themed sites get a light calculator.

Customising the embed

The calculator accepts no URL parameters at present. Every visitor starts with a gross salary of £30,000 and the England region selected. They can then change both fields interactively. If you need a version locked to a specific salary or region for editorial purposes, contact us and we can discuss custom embed options.

The iframe includes a small footer crediting calculatetax.uk. This footer counts as your attribution link. If you prefer to add your own attribution text outside the iframe, that works too, as long as a link to calculatetax.uk is visible somewhere near the widget.

Performance and compatibility

The iframe loads the calculator page, which weighs under 120 KB gzipped including the React runtime. It is built with Astro and served as a static page from Cloudflare's edge network, so response times are typically below 50 ms for UK visitors.

Supported browsers: Chrome, Firefox, Safari, Edge (all versions released since 2022). Mobile browsers on iOS and Android are fully supported. The calculator layout is responsive and stacks vertically on screens narrower than 640 pixels.

No external API calls are made. The tax calculation logic runs client-side using hardcoded 2025-26 HMRC thresholds and rates. The widget will be updated when HMRC publishes 2026-27 rates, usually in the Autumn Statement or Spring Budget.

Who uses embeddable tax calculators?

Finance bloggers and personal finance publishers add salary calculators alongside articles about pay rises, job offers, and negotiation strategies. Recruitment agencies embed them on job listing pages so candidates can see the after-tax value of an offer. HR departments include them in internal compensation portals. Accountancy firms use them as lead-generation tools on their websites, offering a free quick check before the visitor books a consultation. University career services link to them from graduate salary guides.

If your audience includes anyone who earns a salary in the UK, the calculator is relevant. The 2025-26 tax year runs from 6 April 2025 to 5 April 2026, and the figures in the widget are accurate for that full period.