Macronutrient Calculator

Use our macronutrient calculator to tailor your approach to your diet so that you are receiving the daily levels of protein, fat and carbohydrates you want.

To use the calculator, start by entering your ideal daily intake of calories. Then, select how many meals you wish to consume daily. Next, click on the drop-down list and pick your desired ratio of carbohydrates/protein/fat. You can customize this ratio ("Custom") or pick one of the five set ratios, which are: 60/25/15, 50/30/20, 40/30/30, 25/45/30 and 10/15/75. Finally, click "Calculate" to find out your appropriate diet strategy.

Definition of Macronutrients

A macronutrient is a nutrient that provides energy or calories. People need nutrients to ensure the smooth operation of a range of bodily functions, including metabolism and growth. The human body requires a large amount of these nutrients, hence the name macronutrient. The three types of this nutrient are protein, fat and carbohydrates.

Protein, fat and carbohydrates each have their own part to play in the body and provide a certain amount of calories per gram consumed. Protein provides 4 calories for every 1 gram consumed as does carbohydrates, while fat provides 9 calories for every 1 gram consumed.

The body can rapidly metabolize carbohydrates, making this macronutrient the favored energy source for your body. In contrast, the vital macronutrient protein breaks down your body's cells and rebuilds them. Finally, fat provides crucial fatty acids and enables you to absorb vitamins that are only soluble in fat. Energy can also be provided by fat.

By understanding the amount of calories that you get from different macronutrients, you will be able to ensure you are receiving the daily intake of calories you require.

Macronutrient Calculator Formulas

We use three key formulas in our macronutrient calculator.

These are:

• calorie needs × carb % / 4 = grams of carbohydrates
• calorie needs × protein % / 4 = grams of protein
• calorie needs × fat % / 9 = grams of fat

References

1. Sacks FM, Bray GA, Carey VJ, Smith SR, Ryan DH, Anton SD, McManus K, Champagne CM, Bishop LM, Laranjo N, et al. Comparison of weight-loss diets with different compositions of fat, protein, and carbohydrates. N Engl J Med 2009; 360:859–73.

2. Taubes G. The science of obesity: what do we really know about what makes us fat? An essay by Gary Taubes BMJ 2013; 346:f1050.

You might also want to use our Protein Calculator and TDEE & BMR Calculator