Add health calculators to your website
Accurate, customisable calculator widgets you drop into any page with one copy-paste. Matches your brand, resizes automatically, and never collects your visitors’ data.
To add a health calculator to your website, choose a widget below, the BMI calculator or heart-rate training zones, then copy the HTML snippet into your page. It is free, needs no signup or API key, and resizes itself to fit any layout.
Live preview
“Auto” follows your visitor’s system setting.
<!-- Smart Health Calculators BMI Calculator widget. Free to use. Please keep the attribution link below in place (required, see Terms). -->
<iframe
id="shc-bmi"
src="https://www.smarthealthcalculators.com/embed/bmi?theme=light&accent=teal&units=metric&id=shc-bmi"
title="BMI Calculator by Smart Health Calculators"
loading="lazy"
style="width:100%;max-width:480px;border:0;overflow:hidden"
height="560"
></iframe>
<script>
window.addEventListener('message', function (e) {
if (e.data && e.data.type === 'shc-embed-size' && e.data.id === 'shc-bmi') {
var f = document.getElementById('shc-bmi');
if (f) f.style.height = e.data.height + 'px';
}
});
</script>
<p style="font:13px/1.4 system-ui,sans-serif;text-align:center;margin:6px 0 0">
<a href="https://www.smarthealthcalculators.com/bmi-calculator" target="_blank" rel="noopener">BMI Calculator</a>
by Smart Health Calculators
</p>Paste this anywhere in your page’s HTML. The widget resizes itself to fit, works on mobile, and never collects your visitors’ data. The widget is free to use as long as the attribution link stays in place. Want it without our branding? See white-label options.
Why embed this widget
Completely free
No account, no API key, no usage limits. Paste it and it works.
Matches your brand
Light, dark or auto theme plus four accent colours to fit your site.
Auto-resizing
The widget reports its height to your page so there is never an awkward scrollbar.
Private by design
All maths runs in the browser. Your visitors’ measurements never leave their device.
Three steps to embed
Customize it
Pick a theme, accent colour and default units. The preview updates live.
Copy the code
Hit copy to grab the ready-made embed snippet.
Paste it in
Drop it into any page, post or site builder that accepts HTML.
Frequently asked questions
Is the widget really free?
Yes. The BMI and heart-rate zone widgets are free to embed on any website, with no signup, no API key and no usage limits. The only condition is that you keep the small "Powered by Smart Health Calculators" link in place.
How do I add the calculator to my website?
Pick a widget, choose a theme and accent colour, then copy the generated HTML snippet and paste it into your page where you want the calculator to appear. It works in any site builder or CMS that accepts an HTML or embed block.
Will it slow down my website?
No. The widget loads in an iframe with lazy loading, so it only loads when it scrolls into view and never blocks the rest of your page. All the calculation runs in the visitor’s browser.
Does the widget collect my visitors’ data?
No. Every calculation happens locally in the browser. Your visitors’ weight, height, age and heart-rate measurements never leave their device and are never sent to a server.
Can I match it to my brand?
Yes. You can choose a light, dark or automatic theme and one of four accent colours. The widget also resizes itself to fit your container and works on mobile.
Can I remove the attribution link?
The free version keeps the attribution link. A one-time white-label licence is available that lets you run the widget without our branding or link. Email smarthealthcalculators@gmail.com to set it up.
Explore the full calculators
Every widget is a compact version of one of our full calculators. Try the complete tools, with charts, detailed breakdowns and guidance.
BMI Calculator
Calculate your Body Mass Index and healthy weight range.
Heart Rate Zone Calculator
Find your target heart rate zones for training and fat burning.
Body Fat Calculator
Estimate your body fat percentage using the U.S. Navy method.
Calorie Needs Calculator
Calculate your TDEE and daily calorie target by activity level.
Free to use, with attribution
The widget is free to use on any website. The one condition is that you keep the “Powered by Smart Health Calculators” badge and its link in place, so your visitors can find the full set of tools. Full details are in our Terms of Service.
Prefer the widget without our branding or link? A white-label license is available for a one-time fee. Email smarthealthcalculators@gmail.com and we will set you up.