T Nation

Intake Calculations to Maintain

how to calculate amount of calories needed to keep even weight?

From “Thib’s Bell Dieting” (Thib’s second post I think).

When I work with my clients I establish their caloric intake this way:

  1. Average muscle growth with no (or minimal) fat gain = Energy expenditure x 105-110%

  2. Significant muscle growth with a small fat gain = Energy expenditure x 115-120%

  3. Maximum growth with a significant gain in fat = Energy expenditure x 125-130%

From the “Carb Cycling Codex”:

First Step: Calculating Your Basal Metabolic Rate

Your basal metabolic rate (BMR) simply means the amount of energy used by your body during a 24-hour period if no activity is performed. In other words, if you’re inactive for 24-hours straight, you’d still “burn” the amount of calories equivalent to your BMR.

Your BMR is a function of your size, sex, and age. It’s also influenced by your metabolic status (hypo or hyperthyroid state for example). We can calculate BMR with the following formulas (by Harris-Benedict):

For Men

BMR = 66 + (13.7 x weight in kg) + (5 x height in cm) - (6.8 x age)

So for a 30 year old bodybuilder of 220lbs (100kg) at 5’11" (178cm) it comes up to:

BMR = 66 + (13.7 x 100kg) + (5 x 178cm) ? (6.8 x 30)

BMR = 2122 calories per day

For Women

BMR = 655 + (9.6 x weight in kg) + (1.7 x height in cm) - (4.7 x age)

So for a 28 year old figure girl of 132lbs (60kg) at 5’6" (165cm) it comes up to:

BMR = 655 + (9.6 x 60kg) + (1.7 x 165cm) ? (4.7 x 28)

BMR = 1380 calories per day

Second Step: Factoring in activity level

The amount of calories found using the Harris-Benedict formula is what your body burns every day, even if you do nothing all day. Obviously, the more active you are the more you’ll burn fuel. So, energy expenditure will be increased when your activity level goes up.

To get an adequate estimation you need to multiply your BMR by an activity level factor:

Activity level factor

Activity level




Very light activity


Light activity


Moderate activity


High activity


Extreme activity

By sedentary we mean doing nothing all day (sleeping and watching TV).

By very light activity we mean doing nothing physical. Working a desk job or on a computer and not performing any type of physical activity during your day.

By light activity we mean having a non-physical job (desk, computer, etc.) but performing some sort of physical activity during the day (e.g. above average walking) but no hard training.

By moderate activity we mean having a non-physical job, performing some sort of physical activity during the day, and including a daily workout session in your routine. This is where most of you are at.

By high activity we mean either training plus a physical job or non-physical job and twice-a-day training sessions.

By extreme activity we mean a very physical job and daily hard training.

So if our 220 pound bodybuilder with a BMR of 2122 calories/day is moderately active, his daily energy expenditure is bumped up to 2122 x 1.6 = 3395 calories per day. This is the amount of food to consume to maintain present body weight.