How To Calculate Your Calorie Requirement

This following section is here to help you make some individual calculations to give you an estimated calorie intake requirement. With that being said it is important to understand the limitations of calculating your daily calorie targets. Your ultimate goal is not to calculate these figures to absolute perfection, nor will you be able to always execute the target to perfection, however an idea set in place is a great starting point to work from. Without this, you will be leaving it to mere guesswork... and that does not usually deliver best results.

OPTION 1 (recommended)

The Harris Benedict Formula (revised by Mifflin & St Jeor in 1990)

Step 1 – Calculate your BMR (Basal Metabolic Rate)


BMR = (10 x weight in kg) + (6.25 x height in cm) – (5 x age in years) + 5


BMR = (10 x weight in kg) + (6.25 x height in cm) – (5 x age in years) - 161

Step 2 – Determine calorie intake to maintain the same weight

Use the list below to multiply your BMR with your activity level. This will result in the calories you need to maintain the same weight. If you are on one of my #CrockFit plans I recommend starting with ‘moderate exercise’ and adjusting if necessary.

Little to no exercise

BMR x 1.2

Light exercise (1-3 days per week)

BMR x 1.375

Moderate exercise (3-5 days per week)

BMR x 1.55

Heavy exercise (6-7 days per week)

BMR x 1.725

Very heavy exercise (twice per day, extra heavy workouts)

BMR x 1.9

Step 3 – Calories for weight loss or weight gain (deficit or surplus) or maintain

Once you have calculated the previous number you need to add or subtract 10%-20% of that number to give a calorie deficit or surplus. You will then have two numbers that you can use as goal posts for your daily calorie target! Alternatively you could keep this number without adding or subtract, to aim to maintain weight, which often helps transform and shape the body even whilst holding the same weight. 


Man – BMR = (10 x 80) + (6.25 x 175) – (5 x 30) + 5

= 800 + 1093.75 – 150 + 5

= 1748.75

Use this BMR with the activity level calculation.

1748.75 x 1.55 = 2710.5

This man wants to lose weight so will calculate a deficit of 10%-20%.

2710.5 x 0.1(%) = 271.1

2710.5 x 0.2(%) = 542.1


10% = 2710.5 – 271.1 = 2439.4

20% = 2710.5 – 542.1 = 2168.4

So, his daily calorie target is 2168 to 2439.

  • As weight changes you can recalculate again and adjust as you lose or gain weight.

  • Aim for 40% of this calorie intake for protein content.

  • Macro ratios for fats & carbohydrates can fluctuate. If you increase fats, then decrease carbs and visa versa. Whilst protein stays at 40% at least. 



OPTION 2(Only if you’re exercising regularly? lazier/quicker version)

Calculation from target weight

Step 1 – What is your target weight in pounds (lbs)

Whether this is weight gain or weight loss, choose your target weight. But if your target weight is far from where you are currently, then consider choosing a weight target that’s closer, and re calculate when you get to first target.

Step 2 – 1 gram per lb of target bodyweight for protein

Use target weight in pounds for grams of protein.

Step 3 – 1 gram per lb of target bodyweight for carbohydrates

Use target weight in pounds for grams of carbohydrate.

Step 4 – 0.5 gram per lb or target bodyweight for fats

Use target weight and half it for grams of fat.


Your target weight in 185lbs.

Protein = 185g

Carbohydrates = 185g

Fats = 92.5g

Here you can work out calorie intake too with the knowledge that protein and carbohydrates have 4 calories per gram and fats have 9 calories per gram.


Protein - 185 x 4 = 740

Carbohydrates – 185 x 4 = 740

Fats – 92.5 x 9 = 832.5

Calories = 2313

Use MyFitnessPal App to track your calories & macros daily