19 Feb 2013 The calorie calculator estimates both your basal metabolic rate and amount of calories you need to gain, lose or maintain weight. This information is important because the amount you eat compared to the amount you burn is the only way to control weight. Weight plays a very important role in health; knowing how to control it will help you look great, and live a healthier life. Enter your weight, height, age, exercise level and gender into the form below.