BMR And Daily Calories Burned Calculator

Introduction | Demonstration Calculator | Source Code

How The BMR & Daily Calories Burned Calculator Works

How many calories do you need to eat in a day to maintain your current weight? That’s different for each and every individual. The only way to get a highly accurate number is a lab test where you sleep at the lab and they take measurements right as you wake up from 8 hours of sleep and at least 12 hours of fasting.

This calculator uses the formula for Basal Metabolic Rate (BMR) devised by doctors at the University of Nevada Medical School and published in the American Journal of Clinical Nutrition in 1990, then uses the Harris Benedict activity multiplier to determine your estimated daily caloric burn off.

Remember that the Basal Metabolic Rate is how many calories you’d need to maintain your body weight if all you did all day was lay in bed and your only activity was eating. Just sitting up and typing a few hours a day, walking from the couch to your car, from the car to your office, etc. boosts your daily needs up by 20%. If you lead a lifestyle where you have high levels of exertion every day, it can nearly double your calorie needs.

Just fill out the fields in the form below and click “calculate my calorie needs” to get your BMR and your daily calorie needs.

Introduction | Demonstration Calculator | Source Code

Demonstration Calculator


(in years)



Activity Level:

Your Basal Metabolic Rate is:

Your Average Daily Calorie Need is:

Introduction | Demonstration Calculator | Source Code

Daily Calorie Needs Calculator Source Code

This calculator is licensed to you under Creative Commons Attribution 3.0. If you would like to use the source code on your site or create a derivative work from it, you must include the following HTML on the page where the calculator appears. We’re giving you this code for free with a legal license to use it. All you have to do is credit us in the manner we specify.

Required Credit HTML


Just cut and paste the Javascript code and HTML form below into your page. If you want to customize the appearance of the form, feel free. Just make sure the input name and form id/name values are not changed.

<script type="text/javascript">

function calcNeeds(){

var weight = (isNaN(document.wcbubba.weight.value)) ? 0 : document.wcbubba.weight.value;
if (weight == 0) alert("Results will be inaccurate.  Weight is not a valid number.");
var height = (isNaN(document.wcbubba.height.value)) ? 0 : document.wcbubba.height.value;
if (height == 0) alert("Results will be inaccurate.  Height is not a valid number.");
var age = (isNaN(document.wcbubba.height.value)) ? 0 : document.wcbubba.age.value;
if (age == 0) alert("Results will be inaccurate.  Age is not a valid number.");
var activity = (isNaN(document.wcbubba.activity.value)) ? 0 : document.wcbubba.activity.value;

var wmult = (document.wcbubba.units.value == "pounds") ? 2.204 : 1;
var hmult = (document.wcbubba.hunits.value == "inches") ? 2.54 : 1;
var genvar = (document.wcbubba.gender.value == "male") ? 5 : -161;

var BMR = Math.round((((weight / wmult) * 9.99) + ((height * hmult) * 6.25) - (age * 4.92) + genvar) * 1);

var calburn = Math.round((((weight / wmult) * 9.99) + ((height * hmult) * 6.25) - (age * 4.92) + genvar) * activity);

document.getElementById('results').innerHTML = "Your Basal Metabolic Rate is: " + BMR + " calories.<br><br>Your Average Daily Calorie Need Is: " + calburn + " calories";


<form name="wcbubba" id="wcbubba" action="javascript:void()">
Weight:<br> <input type=text name="weight" size="6"> <select name="units"><option value="pounds">pounds<option value="kilos">kg</select><br><br>
Age:<br><input type=text name="age" size="6"> (in years)<br><br>
Gender:<br><select name="gender"><option value="male">male<option value="female">female</select><br><br>
Height:<br> <input type=text name="height" size="6"> <select name="hunits"><option value="inches">inches<option value="cm">cm</select><br><br>
Activity Level:<br> <select name="activity">
<option value="1.2">Little or no exercise and desk job
<option value="1.375">Lightly strenuous exercise or casual sports 1-3 days a week
<option value="1.55">Moderately strenuous exercise or somewhat aggressive sports 3-5 days a week
<option value="1.725">Strenuous exercise or aggressive sports 6-7 days a week
<option value="1.9">Strenuous daily exercise or aggressive sports and a physically active job</select><br><br>
<input type="submit" value="Calculate My Calorie Needs" onClick="calcNeeds();"></form><br>
<div id="results" style="border:1px solid #000;padding:4px;font-size:15px;font-weight:bold;width:400px;">
Your Basal Metabolic Rate is:<br><br>
Your Average Daily Calorie Need is:

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