Calorie Calculator

What are calories and what is their relation to weight gain or loss?

Calories are a measure of the amount of energy in food. The calorie content of many foods is stated on the nutrition label under the heading ‘Energy’, with the calorie content given in ‘kcals’.

Energy balance occurs when total energy intake from food matches energy expenditure from daily activity. Energy is provided by the carbohydrate, protein, fat (macronutrients) and alcohol in food and fluids.

If the calories consumed are greater than those expended then the extra calories will be stored, most likely as excess body fat.

Calorie intake is therefore key for any weight loss or weight gain plan. You should aim to be in a calorie deficit to lose weight or in a surplus to gain weight, meaning you should eat fewer or more calories than your body needs.

Energy intake is estimated at 2,000 calories per day for women and 2,500 calories per day for men. These are very basic and general guidelines that do not take any specific individual requirements into account.

My calculator uses the Harris-Benedict equation to provide a better estimate of individual daily energy needs, taking gender, age, height, weight and activity levels into consideration.

My calculator will provide you with the following:

Your BMR, BMI and your daily calorie and macronutrient recommendations for your goals, whether that be weight loss, maintenance or gain.

BMR: Your BMR (Basal metabolic rate) is the number of calories that your body uses to perform no activity whatsoever – just it’s basic life sustaining functions.

BMI: Body mass index (BMI) provides information about the amount of body weight within each square metre of the body and is measured using kilograms per metre squared (kg/m2). As BMI uses weight only and does not consider body composition, it is not appropriate for measuring fat loss. However, it is useful as a quick method to determine body weight compared to national guidelines and as a potential factor for disease risk.


Complete this form to get a breakdown of your calorie requirements based on your goals. I will also send you my guide to tracking calories.

Any calculation is to be used as a guide only because there may be other contributing factors which affect your BMR and your maintenance calories.

Units system
Activity Level