Basal Metabolic Rate (BMR) Calculator in PHP

Basal Metabolic Rate (BMR) with this calculator tool. Your BMR is the amount of energy you expend each day when at rest. This calculator will also work out your daily calorie requirements.

Basal Metabolic Rate (BMR) formula Finds result on the factor of age,height, weight and gender. This tool made by Harris Benedict and also calls Harris Benedict Equation to determine your total daily energy expenditure (calories). The Harris Benedict Equation is a formula that uses your BMR and then applies an activity factor.

Formula of Basal Metabolic Rate (BMR)

1. Weight in Kg And Height in Cm (Metric Formula)

Women: BMR = 655.1 + ( 9.563 × weight in kg ) + ( 1.850 × height in cm ) – ( 4.676 × age in years )
Men: BMR = 66.5 + ( 13.75 × weight in kg ) + ( 5.003 × height in cm ) – ( 6.755 × age in years )

2. Weight in Pounds And Height in inch (English Imperial Formula)

Women: BMR = 655.1 + ( 4.35 × weight in pounds ) + ( 4.7 × height in inches ) – ( 4.7 × age in years )
Men: BMR = 66 + ( 6.2 × weight in pounds ) + ( 12.7 × height in inches ) – ( 6.76 × age in years )

Function

	function bmr_calories_metric($age, $height_cm, $weight_kg, $gender, $kilojoules = false) {
		$bmr = 0;
		if ($gender == "women") {
			//		Women Metric 	BMR = 655.1 + ( 9.563 × weight in kg ) + ( 1.850 × height in cm) – ( 4.676 × age in years )
			$bmr = 655.1 + (9.563 * $weight_kg) + (1.850 * $height_cm) - (4.676 * $age);
		}
		if ($gender == "men") {
			//Men 	Metric 	BMR = 66.5 + ( 13.75 × weight in kg ) + ( 5.003 × height in cm ) – ( 6.755 × age in years )
			$bmr = 66.5 + (13.75 * $weight_kg) + (5.003 * $height_cm) - (6.755 * $age);
		}
		if ($kilojoules) {
			$bmr = $bmr * 4.184;
		}
		return $bmr;
	}
	function bmr_calories_imperial($age, $height_inch, $weight_pound, $gender, $kilojoules = false) {
		$bmr = 0;
		if ($gender == "women") {
			//Women: Imperial 	BMR = 655.1 + ( 4.35 × weight in pounds ) + ( 4.7 × height in inches ) - ( 4.7 × age in years )
			$bmr = 655 + (4.35 * $weight_pound) + (4.7 * $height_inch) - (4.7 * $age);
		}
		if ($gender == "men") {
			//Men Imperial 	BMR = 66 + ( 6.2 × weight in pounds ) + ( 12.7 × height in inches ) – ( 6.76 × age in years )
			$bmr = 66 + (6.2 * $weight_pound) + (12.7 * $height_inch) - (6.76 * $age);
		}
		if ($kilojoules) {
			$bmr = $bmr * 4.184;
		}
		return $bmr;
	}

Program

<?php
	function bmr_calories_metric($age, $height_cm, $weight_kg, $gender, $kilojoules = false) {
		$bmr = 0;
		if ($gender == "women") {
			//		Women Metric 	BMR = 655.1 + ( 9.563 × weight in kg ) + ( 1.850 × height in cm) – ( 4.676 × age in years )
			$bmr = 655.1 + (9.563 * $weight_kg) + (1.850 * $height_cm) - (4.676 * $age);
		}
		if ($gender == "men") {
			//Men 	Metric 	BMR = 66.5 + ( 13.75 × weight in kg ) + ( 5.003 × height in cm ) – ( 6.755 × age in years )
			$bmr = 66.5 + (13.75 * $weight_kg) + (5.003 * $height_cm) - (6.755 * $age);
		}
		if ($kilojoules) {
			$bmr = $bmr * 4.184;
		}
		return $bmr;
	}
	function bmr_calories_imperial($age, $height_inch, $weight_pound, $gender, $kilojoules = false) {
		$bmr = 0;
		if ($gender == "women") {
			//Women: Imperial 	BMR = 655.1 + ( 4.35 × weight in pounds ) + ( 4.7 × height in inches ) - ( 4.7 × age in years )
			$bmr = 655 + (4.35 * $weight_pound) + (4.7 * $height_inch) - (4.7 * $age);
		}
		if ($gender == "men") {
			//Men Imperial 	BMR = 66 + ( 6.2 × weight in pounds ) + ( 12.7 × height in inches ) – ( 6.76 × age in years )
			$bmr = 66 + (6.2 * $weight_pound) + (12.7 * $height_inch) - (6.76 * $age);
		}
		if ($kilojoules) {
			$bmr = $bmr * 4.184;
		}
		return $bmr;
	}
	$answer = "";
	$dob = "";
	$feet = "";
	$inches = "";
	$weight = "";
	$gender = "";
	$result = "";
	function yeardob($dob_val) {
		$dob = new DateTime($dob_val);
		$today = new DateTime('today');
		$obj = date_diff($dob, $today, FALSE);
		return $obj->y;
	}
	if (isset($_POST["bmrsubmit"])) {
		$dob = $_POST['dob'];
		$feet = $_POST['feet'];
		$inch = $_POST['inch'];
		$weight = $_POST['weight'];
		$gender = $_POST["gender"];
		/* Age */
		$dob = new DateTime($dob);
		$today = new DateTime('today');
		$obj = date_diff($dob, $today, FALSE);
		$age = $obj->y;
		$date = $dob->format("Y-m-d");
		/* Covert height */
		$feetcm = $feet * 30.48;
		$inchcm = $inch * 2.54;
		$cm = $feetcm + $inchcm;
		$bmr = bmr_calories_metric($age, $cm, $weight, $gender, false);
		$activity = $_POST["activity_level"];
		$bmrkj = $bmr * 4.184;
		switch ($activity) {
			/*
			 If you are sedentary (little or no exercise) : Calorie-Calculation = BMR x 1.2
			 If you are lightly active (light exercise/sports 1-3 days/week) :
			 Calorie-Calculation = BMR x 1.375
			 If you are moderatetely active (moderate exercise/sports 3-5 days/week) :
			 Calorie-Calculation = BMR x 1.55
			 If you are very active (hard exercise/sports 6-7 days a week) :
			 Calorie-Calculation = BMR x 1.725
			 If you are extra active (very hard exercise/sports & physical job or 2x
			 training) : Calorie-Calculation = BMR x 1.9
			 */
			case 1 :
				$activity_type = "No Activity or No Exercise";
				$calories = $bmr * 1.2;
				break;
			case 2 :
				$activity_type = "Light Exercise/Sports 1-3 Days/Week";
				$calories = $bmr * 1.375;
				break;
			case 3 :
				$activity_type = "Moderate Exercise/Sports 3-5 Days/Week";
				$calories = $bmr * 1.55;
				break;
			case 4 :
				$activity_type = "Hard Exercise/Sports 6-7 Days a Week";
				$calories = $bmr * 1.725;
				break;
			case 5 :
				$activity_type = "Very Hard Exercise/Sports & Physical Job or 2x Training";
				$calories = $bmr * 1.9;
				break;
			default :
				$activity_type = "No Activity or No Exercise";
				$calories = $bmr * 1.2;
				break;
		}
		$kilojoules = $calories * 4.184;
		$result = "<p>According to the Age $age Weight $weight Kg And Height $feet'$inch\" ($cm Cm) a ".ucfirst($gender).". BMR is  ".number_format($bmr).".</p><p>if you engage in $activity_type for that day. The estimate for maintaining your current weight (based upon your chosen activity level) is ".number_format($calories)." calories (".number_format($kilojoules)."KJ). </p> ";
	}
?>
<form method='post' >
	<p>Date of Birth : <input type="date" name="dob" value="<?php echo $date; ?>" required /></p>
	<p>Feet : <input type="number" name="feet" value="<?php echo $feet; ?>"   step="1" min="1" max="10" required  /> Inch : <input type="number" value="<?php echo $inch; ?>" min="0"  max="11" maxlength="2" name="inch" step="1" required  /></p>
	<p>Gender : <input type="radio" name="gender" value="women" <?php echo($gender == "women") ? "checked" : ""; ?> required  /> Women <input type="radio" name="gender" value="men" <?php echo($gender == "men") ? "checked" : ""; ?> /> Men </p>
	<p>Weight :<input type="number" name="weight" value="<?php echo $weight; ?>" step="1"  required  /></p>
	<p>
		<select name="activity_level" >
			<option>Select  Exercise Type</option>
			<option value="1">No Activity or No Exercise</option>
			<option value="2">Light Exercise/Sports 1-3 Days/Week</option>
			<option value="3">Moderate Exercise/Sports 3-5 Days/Week</option>
			<option value="4">Hard Exercise/Sports 6-7 Days a Week</option>
			<option value="5">Very Hard Exercise/Sports & Physical Job or 2x Training</option>
		</select></p>
	<p><input type="submit" name="bmrsubmit" value="Get Result" /></p>
	<?php
	echo $result;
?>
</form>

Demo