You can embed our SDLT calculator on your own website at no cost. Useful if you're a solicitor, mortgage broker, estate agent, or property blogger who wants to give visitors an instant stamp duty figure without sending them somewhere else.

Basic embed

Paste this snippet into your page where you want the calculator to appear:

<iframe
  src="https://dutycalculatorstamp.co.uk/embed.html"
  width="100%"
  height="900"
  style="border:0;max-width:760px;display:block;margin:0 auto"
  title="UK Stamp Duty Calculator"
  loading="lazy"></iframe>

Pre-fill the calculator

Pass query-string parameters to land the user on a specific scenario. Useful if your page is about first-time buyers or buy-to-let — you can pre-select the right buyer type so they don't have to.

• ?price=400000 — pre-fill the property price (in pounds, no commas)
• ?type=ftb — pre-select first-time buyer
• ?type=additional — pre-select additional property (buy-to-let, second home)
• ?nr=1 — tick the non-UK resident box

You can combine them: ?price=350000&type=ftb

<iframe
  src="https://dutycalculatorstamp.co.uk/embed.html?type=ftb&price=350000"
  width="100%"
  height="900"
  style="border:0;max-width:760px;display:block;margin:0 auto"
  title="First-time buyer SDLT calculator"
  loading="lazy"></iframe>

Responsive height

The simplest setup uses a fixed height (like 900px above). If you want the iframe to auto-resize as content changes, drop in this small script after the iframe:

<script>
  window.addEventListener('message', function(e) {
    if (e.origin !== 'https://dutycalculatorstamp.co.uk') return;
    if (e.data && e.data.sdcHeight) {
      var f = document.querySelector('iframe[src*="dutycalculatorstamp.co.uk"]');
      if (f) f.style.height = e.data.sdcHeight + 'px';
    }
  });
</script>

Note: this requires the embed page to post its height — that integration is on our roadmap. For now, set a height that comfortably contains the result on most prices.

Branding & attribution

The embed includes a small "Calculator by dutycalculatorstamp.co.uk" credit at the bottom. We ask that you keep this in place — it's how we keep the calculator free.

Terms of use

The embed is free for non-commercial and commercial use. Please don't modify the SDLT logic, remove the credit, or claim the calculator as your own. We may change the rates or design without notice as HMRC updates the rules — your iframe will reflect the latest version automatically. Full terms on the terms page.

Want a white-label or self-hosted version?

Email contact@dutycalculatorstamp.co.uk if you need a branded or self-hosted build, an API endpoint, or custom rate handling.

Last updated: 1 May 2026.