Macronutrient Calculator

“How much and what should I actually be eating?” – Sound like a familiar question? Don’t worry, millions of people are asking this question every single day. Diet varies for everyone, and exercise level plays a major factor into how your body responds to your nutrition levels and intake, but there are in fact a few guidelines in place to help you understand what steps to take.

The American College of Sports Medicine (ACSM) derived a simple formula that is widely accepted to help determine this by structuring your macronutrient (proteins, carbohydrates, and fats) intake, balanced with exercise, to help you tone down and maintain weight. This formula is the science behind determining how much of each macronutrient you should intake. Let’s get started.

First, take your body weight and multiply it by one of the following indices. “Add Mass” means you are trying to gain body mass, “Maintain” means you are trying to keep a consistent weight level, and “Lose Weight” means you’re trying to lose weight.


  • Add Mass          18
  • Maintain           15
  • Lose Weight     12

Whatever number this gives you, this is your ideal Caloric intake (i.e. If you weigh 150 pounds are are trying to maintain weight, multiply that by 15 to get a daily Caloric intake of 2250 Calories. Most nutrition facts on food labels are based on a 2000 Calorie diet.) Now determine how you will weight your diet: how much of each macronutrient should be in your daily diet? That’s wholly up to you. Below is a base weighting that is widely accepted, but often times people alter the percentages based off their preferences and lifestyle (because this is YOUR journey).


  • Protein                15%
  • Carbohydrates   65%
  • Fat                        20%

Multiply each percentage per macronutrient by your daily Caloric intake, and that’s how many calories of each macronutrient your plan requires. Wait, how do you measure calories of protein? This is where you do conversions. Note that the conversion factor for Calories to grams for fats is higher than the one for carbohydrates and protein because fats are more complex. Multiply your Caloric weighting by the following conversions to get the daily amount of macronutrients in grams.


  • Proteins                4
  • Carbohydrates     4
  • Fats                        9

Once you have done this, you will have an idea of how much of each macronutrient to eat each day to meet your ideal nutrition goals. Remember, these are guidelines and not a specific regimen.

This is how you find a guideline on how much to eat daily to lose and maintain weight. Check out the blog posts for ideas on what, how, and when to eat to meet these goals.