Looking for a BMI calculator widget with wellness tips for a fitness club site

We run a small fitness club and want to add an interactive widget to our website that helps visitors estimate their body mass index. The idea is simple: a person enters their height and weight, the widget calculates the BMI score, shows which category it falls into, and displays a short block of general lifestyle suggestions — things like staying active, balanced eating habits, and regular movement. We want to be very clear that this is not meant to give medical advice or diagnose anything; it should read as friendly, general wellness information, with a visible note reminding visitors to consult a specialist for anything beyond casual curiosity.

The widget should work smoothly on both desktop and mobile, support metric units, and update the result instantly without reloading the page. Visual style matters too — we would like it to match the clean, energetic look of our existing site, with a progress bar or color-coded scale that makes the category easy to read at a glance, without a wall of text next to the number.

What we expect from the freelancer:
— a working calculator widget (HTML/CSS/JS) that can be embedded into our current site
— input validation for height and weight fields
— clear category labels and a general lifestyle tips block with a disclaimer
— responsive layout tested on a few common screen sizes
— basic accessibility (labels, keyboard input support)

Please share similar widgets you have built before, along with your estimated timeline and price.