Wondering how many calories you should eat per day? Here’s how to calculate your BMR (basal metabolic rate), PAL (physical activity level) and daily calorie needs to stay a healthy weight…

Discover how to eat a more balance diet with the Eatwell Plate

Although calories are feared by many dieters your body needs them to survive and function at its best. The number of calories needed each day for the body to function efficiently is different for each individual. Your weight, age and activity level are the main factors that determine your daily calorie requirement.

How to calculate your daily calories

Your body requires a certain number of calories each day just to survive. This is called your basal metabolic rate (BMR). In order to perform any other activity – exercise or an active job – your body requires more calories for fuel. This is referred to as your physical activity level (PAL). To find your individual daily calorie requirement, simply multiply your BMR by your PAL rating – see calculation instructions below.

How many calories should I eat per day for weight loss?

This equation calculates the number of calories you would need to consume every day in order to maintain your current weight. If your goal is to lose weight, you should aim to reduce your daily calorie intake by 500-700 calories, which would lead to a manageable weight loss of 1-2lbs each week. If you cut any more calories than this, you will be restricting your diet too much and your energy, concentration and general wellbeing will suffer.

You can cut calories by reducing your food intake and/or by increasing your activity level in order to burn extra calories. A combination of the two is most effective.

Macronutrient calories

Once you have calculated your daily calorie intake, you can then find out how much carbohydrate, protein and fat your diet should include. As a guideline, 50-55 per cent of your energy each day should come from carbohydrates, 30-35 per cent from fat and 10-15 per cent from protein.

In each gramme of protein and carbohydrate there are four calories. In one gramme of fat there are nine calories. By doing this, you can make sure you’re eating the right balance.

How to calculate your BMR, PAL and daily calories

M=Male F=Female

How to calculate your basal metabolic rate (BMR)

Age BMR male  BMR female
10–17 years 17.7 x weight (kg) + 657 13.4 x weight (kg) + 692
18–29 years 15.1 x weight (kg) + 692 14.8 x weight (kg) + 487
30–59 years 11.5 x weight (kg) + 873 8.3 x weight (kg) + 846
60–74 years 11.9 x weight (kg) + 700 9.2 x weight (kg) + 687

How to calculate your physical activity level (PAL)

table showing how to calculate your physical activity level PAL


A woman aged 34, weighing 70kg has a BMR of 1,427 calories. (8.3 x 70 + 846 = 1,427 calories). The woman has a sedentary office job, but runs triathlons in her spare time.

Her PAL rating is 1.6. By multiplying her BMR by her PAL rating, we can see she needs 2,283 calories each day. (1,427 x 1.6 = 2,283 calories)

Related content:

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  3. The best carbs for runners & and when to eat them