How it works
The calculator first estimates your total daily energy expenditure (TDEE) using the Mifflin-St Jeor equation — a widely used, validated formula — multiplied by an activity factor. It then adjusts your calories for your goal: a modest deficit of about 500 kcal for weight loss, no change to maintain, or a small surplus of about 300 kcal to gain. Finally it divides those calories across your chosen macro split, using 4 kcal per gram for carbs and protein and 9 kcal per gram for fat.
Protein matters more as women age. Muscle is easier to lose and harder to build after menopause, and getting enough protein — often at the higher end of the recommended range — supports strength, bone health, and appetite. If you lift weights or are very active, a higher-protein split can help.
These are starting estimates, not prescriptions. Metabolism, medical conditions, medications, and life stage all shift real needs, and very low-calorie targets aren't safe or sustainable. A registered dietitian can tailor macros to your health, preferences, and goals.