How to Calculate Calorie Needs and Macronutrient Ratios

The first step in making a body composition change is to determine your goal and which caloric state you need to be in. If your goal is weight loss, you need to be in a caloric deficit or consume fewer calories than you expend. To gain weight you will need to be in a caloric surplus, or consume more calories than you expend. And to maintain, you will need a balance between calories consumed and expended.

Although protein, carbohydrate, and fat ratios are important, the single most important factor in weight change is calorie intake. So, once you have your body composition goal, it’s time to answer the question, “How many calories do I need to reach that goal?”

Before we dive in on how to answer this question – the best piece of advice I can give on determining how many calories you need is to not stress yourself out over it. None of the calculations we’ll go over will ever be 100% precise. Everyone is different, and there are a TON of factors that influence your metabolic rate. Hormones, muscle to fat ratio, age, diet composition, food quality, genetics, and more can all play a huge role in metabolic rate and daily calorie needs. A good example of this would be the friend who eats everything in sight and never gains a pound.

This discrepancy between individual metabolic rates makes it difficult to calculate calories with any one formula or equation. The formulas provided below work for a large percentage of people, but the most accurate way to find how many calories you need in a day is to precisely track your food intake for 1-2 weeks. If you are ok with a “ballpark” number, there is no need to do this. But if you want the most accurate number for your caloric needs, use the steps below.

And don’t worry, tracking your calories or food intake doesn’t have to be a lifelong thing. That is, unless you want it to be. Section three of Nutrition Made Easy covers an eating strategy that can potentially alleviate the need to track nutrition or adopt any “diet” or specific eating protocol.

A quick step by step guide on how to calculate calorie needs for your goal:

1. Record your current body weight.
2. Track everything you eat or drink for an allotted time period.
3. At the end of your tracking period, divide your total calories by the number of days you tracked. (If you ate a total of 21,000 calories in a week that would be 21,000/7 days for an average of 3,000 calories/day.)
4. Record your weight after the tracking period.
   1. If your weight remained the same – 3,000 calories/day is close to your maintenance calorie level
   2. If you gained weight – Your daily calorie needs are less than 3,000/day. How much will depend on the amount of weight gained. If your weight increased by .25 pounds, you might do better with 2,750/day. If you gained over one pound in a week you may need to drop closer to 2,250 or so.
   3. The same scenario applies to losing weight, only in the reverse order.

There are plenty of formulas that require tons of input like age, height, and include conversions with more math. If you just need a place to start, a fairly simple method you could use is a body weight multiplier. A body weight multiplier takes into account your current body weight and the amount of time you are exercising or training in a week’s time. The only variable that changes with a body weight multiplier is the base number that correlates with your goal.

Weight Loss

Body weight X (8-9 + Weekly Training Hours)
Example: A 150lb woman exercising 3 hours per week: 150 X (9+3) = 1,800 calories/day

Weight & Muscle Gain

Body weight X (14 + Weekly Training Hours)

Weight Maintenance

Body weight X (11-12 + Weekly Training Hours)
There are a few other factors to consider with body weight multipliers.

• Lifestyle and work environment – If you have a completely sedentary job and lifestyle (like a student), these numbers may be a bit lower. On the other hand, if you’re moving around all day or perform manual labor, you’ll likely need to increase these calories.
• Your metabolic rate is not set in stone. As you gain or lose weight, your metabolic rate may change with it. A heavier person typically burns more calories at rest than a lighter person.
• Training intensity – If you are a competitive athlete, you may need to add training hours to account for the elevated intensity. If you are only walking the dog a few times a week you may want to be less generous with your training hour total.

Remember that these numbers are only a place to start, and will likely need to be adjusted over time. Be sure to avoid making too drastic of a change all at once. Decreasing or increasing your calories by over 500 at one time is a mistake and is not a maintainable strategy. The best rate of weight loss or gain is around one pound per week with a maximum of around two pounds per week in either direction. Sticking to a pace that is sustainable will benefit your overall health and set you up for long-term success.