Free widget

Free EV charging cost calculator for your website

Last checked: 15 October 2026 · PlugLater

Add a free EV charging cost calculator to your website. It compares home off-peak charging with the Ofgem price cap and public rapid charging for 37 popular UK EVs, or any car’s miles per kWh. Paste one snippet; nothing else to install.

Privacy-friendly by design. The widget is one HTML file with no cookies, no local storage, no analytics, no external fonts or scripts, and no tracking of your visitors, so it doesn’t add anything to your cookie banner. It only sends its own height to your page (for the optional auto-resize script below).

Preview

Copy-paste code

Standard (light):

<iframe src="https://www.pluglater.co.uk/embed/ev-charging-calculator.html" title="EV charging cost calculator" width="100%" height="560" style="border:0;max-width:640px;width:100%" loading="lazy"></iframe>
<p style="font-size:12px"><a href="https://www.pluglater.co.uk/">Powered by PlugLater</a></p>

Dark sites:

<iframe src="https://www.pluglater.co.uk/embed/ev-charging-calculator.html?theme=dark" title="EV charging cost calculator" width="100%" height="560" style="border:0;max-width:640px;width:100%" loading="lazy"></iframe>
<p style="font-size:12px"><a href="https://www.pluglater.co.uk/">Powered by PlugLater</a></p>

Start on a car and mileage (example: BYD Sealion 7, 10,000 miles):

<iframe src="https://www.pluglater.co.uk/embed/ev-charging-calculator.html?car=sealion7&miles=10000" title="EV charging cost calculator" width="100%" height="560" style="border:0;max-width:640px;width:100%" loading="lazy"></iframe>
<p style="font-size:12px"><a href="https://www.pluglater.co.uk/">Powered by PlugLater</a></p>

Optional auto-resize (paste once, anywhere after the iframe):

<script>
window.addEventListener("message", function (e) {
  if (e.origin !== "https://www.pluglater.co.uk" || !e.data || e.data.type !== "smartshift-embed-height") return;
  document.querySelectorAll('iframe[src^="https://www.pluglater.co.uk/embed/"]').forEach(function (f) { f.style.height = (e.data.height + 4) + "px"; });
});
</script>

Options

theme=dark: dark colours.
miles=10000: starting mileage.
home=7.5: starting home off-peak rate in pence (default 7.6p, Intelligent Octopus Go).
car=…: starting car. IDs: q4, i4, ix1, atto3, dolphin, seal, sealion7, ec3, born, f600, explorer, puma, ioniq5, ioniq6, kona, ev3, ev4-h81, ev6, cla, mgs5-lr, mg4, mini-cooper, leaf, e2008, e208, polestar-2, r4, r5, elroq, enyaq, model-3, model-y, corsa, mokka, id3, id4, ex30.

Terms

Free for any website, including commercial ones such as installers, dealers, EV clubs and blogs.
Please keep the small “Powered by PlugLater” credit. You don’t need to add any other link.
The widget loads from this site, so when its rates are updated your embed shows the new figures without any change on your side. Current figures were checked 15 October 2026.
The figures are worked examples, not financial advice or a quote.

Questions about the embed: stephen@smartshift-uk.com.

Questions people ask

Is the PlugLater calculator widget free?

Yes. It is free for any website, including commercial sites. Please keep the small “Powered by PlugLater” credit.

Does the widget use cookies or track visitors?

No. It is a single HTML file with no cookies, local storage, analytics or third-party scripts, so it doesn’t need a consent banner.

Which rates does it use?

7.6p/kWh for Intelligent Octopus Go overnight, 26.32p/kWh for the Ofgem price cap average (October–December 2026) and 75p/kWh as an illustration of public rapid charging, checked 15 October 2026. Visitors can change the home and public rates.

How do I change the size?

Set the iframe height, or paste the optional auto-resize script once on the page.

Not financial advice. These are worked examples from published rates and EV-Database consumption estimates, for planning only. Your own tariff, day rate, standing charge, car, driving and weather will change the numbers. Check your bill and your supplier’s current terms before you switch or buy anything.

Sources

This page has no affiliate links. The calculator on the homepage is free and runs in your browser.