Methodology

Every MacroCalcs result comes from a published, peer-reviewed formula. Here's what we use and why.

Energy

• Resting energy: Mifflin-St Jeor (1990) by default. Katch-McArdle when body fat is provided. Revised Harris-Benedict (Roza & Shizgal, 1984) shown for comparison.
• Activity multipliers: 1.2 (sedentary), 1.375, 1.55, 1.725 and 1.9 (extra active).
• Weight change: about 3,500 kcal per pound (7,700 per kg) of body fat. Minimum intakes of 1,200 kcal (women) and 1,500 kcal (men) are enforced.

Macros and protein

• Protein targets of 0.8–2.4 g/kg follow the U.S. RDA and the International Society of Sports Nutrition position stand on protein and exercise.
• For a BMI of 30 or above, protein is based on the weight at a BMI of 27.5 to avoid overestimating needs.
• Fat is set at 25–40% of calories depending on diet style; carbs fill the remainder.

Body composition

• BMI: World Health Organization adult categories.
• Body fat: U.S. Navy circumference equations (Hodgdon & Beckett); categories from the American Council on Exercise.
• FFMI: Kouri et al. (1995), normalized to 1.8 m.
• Lean body mass: Boer (1984), James (1976) and Hume (1966).

Training

One rep max is the average of the Epley, Brzycki and Lombardi equations.

Hydration

About 33 ml per kg of body weight, plus 350 ml per 30 minutes of exercise and 500 ml for hot climates, alongside the National Academies' adequate intake values.

Limits

These results are estimates for healthy adults and are not medical advice. If you are pregnant, breastfeeding, under 18, or managing a medical condition, talk to your doctor or a registered dietitian.