BMI.php

<?php
class BMI
{
    function index($height = 162.6, $weight = 84)
    {
        $result = new stdClass();
        $cm = $height;
        $kg = $weight;
        $meter = $cm / 100;
        $inches = $meter * 39.3700787;
        $feet = round($inches / 12);
        $inches = $inches % 12;
        $result->bmi = round($kg / ($meter * $meter), 2);
        $lb = round($kg / 0.45359237, 2);
        if ($result->bmi < 18.5) {
            $result->message = 'Underweight';
        } elseif ($result->bmi <= 24.9) {
            $result->message = 'Normal weight';
        } elseif ($result->bmi <= 29.9) {
            $result->message = 'Overweight';
        } else {
            $result->message = 'Obesity';
        }
        $result->metric = array(
            'height' => "$cm centimeter",
            'weight' => "$weight kilograms"
        );
        $result->imperial = array(
            'height' => "$feet feet $inches inches",
            'weight' => "$lb pounds"
        );
        return $result;
    }
}