Free Embeddable Health Calculators

Add interactive metabolic risk calculators to your website or blog. No account. No API key. No cost. Two-line snippet, works on most website platforms.

Copy the two lines of code for any calculator below and paste them into your article or page. The widget will render automatically. Supports data-theme="dark" and data-units="imperial" attributes. One <script> tag per page is enough — add as many <div> elements as you like.

Waist-to-Height Ratio Calculator

The most evidence-backed single number for metabolic risk. Calculates WHtR and plots it on a colour-coded gauge with a healthy waist ceiling reference.

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Body Roundness Index Calculator

BRI models the body as an ellipsoid. A more nuanced alternative to BMI and WHtR, with sex-specific cutoffs validated in population studies.

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Healthy Waist Size Calculator

Shows the healthy waist ceiling, elevated risk threshold, and high-risk threshold for any height. Ideal for articles focused on waist measurement goals. Includes a built-in cm/in unit toggle.

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Conicity Index Calculator

Conicity Index measures abdominal fat distribution using height, weight, and waist circumference. Sex-specific cutoffs derived from cardiovascular risk research.

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BMI Calculator

Classic Body Mass Index. Simple weight-and-height ratio with category badge. Useful as baseline context alongside waist-based measurements.

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Works on most website platforms

WordPress
Ghost
Webflow
Squarespace
Wix
Substack
Static HTML

Frequently asked questions

Is it free?

Yes, completely free. No account, no API key, no usage limits. The calculators are self-contained — your readers' data never leaves their browser.

Will it slow my page?

No. The script is under 5 KB gzipped, loads asynchronously, and has no external dependencies. It won't affect your Core Web Vitals score.

Will the widget styles clash with my site's CSS?

No. Each widget runs inside a Shadow DOM, which fully isolates it from your page's styles. Your CSS can't break the widget, and the widget can't override your CSS.

Does it work on WordPress?

Yes. Paste the two lines into the HTML block of any post or page. Works with the classic editor and the block editor (Gutenberg). No plugin needed.

Can I use multiple calculators on the same page?

Yes. Include the <script> tag once per page, then add as many <div data-irr="..."> elements as you need. Each renders independently.

Can I customise the colour theme?

The widget ships with a light theme (default) and a dark theme via data-theme="dark". Custom brand colours are not currently supported, but the neutral design fits most sites without adjustment.

Do readers need to create an account or install anything?

No. The calculator runs entirely in the browser. No login, no cookies, no data sent to any server.

Are these medical diagnostic tools?

No. These are educational screening tools, not diagnostic tools. They do not replace medical advice, blood tests, or clinical evaluation. Readers with health concerns should consult a qualified healthcare professional.

Does the widget include attribution?

Yes. A small "Powered by InResRisk" link appears below each calculator. This helps us keep the widgets free for everyone — no account, no API key, no cost to you or your readers.