How to work out your daily calorie intake. To begin with work out your basic metabolic rate (BMR) – The amount of calories you burn a day at rest. Multiply your BMR by the category you fall in. It’s a good base to know how many calories are appropriate for your weight, height and activity level. Although calorie counting can work for some not all have weight loss success. In addition, calories aren’t all equal. 200 calories in an avocado is far more nutritious than 200 calories of chips. Contact me for help.