Macronutrient Calculator

It anchors protein to your ideal body weight — protein grams = ideal body weight (lbs) × a protein factor — then converts that to calories (grams × 4). Whatever calories remain from your daily target are split between carbohydrates and fat by goal. Protein is set first as a fixed amount; carbs and fat fill the rest. Set the daily target with the TDEE Calculator first.

Because percentage-based protein falls exactly when you need it most. If protein is a fixed share of calories and you cut calories for fat loss, your protein grams drop too — right when preserving muscle matters. Anchoring protein to a body-weight target keeps the grams constant regardless of the calorie level, so a deficit trims carbs and fat while protein stays put. It is a more muscle-protective way to build the plan.

This tool uses a factor of 0.6 to 1.4 grams per pound of ideal body weight. The 0.6–0.8 range suits most general goals; 0.8–1.0 fits active people; 1.0–1.4 fits athletes, high-protein diets, or carnivore approaches. Higher protein supports muscle retention in a deficit and satiety generally, but there is a point of diminishing returns — most people do well in the middle.

After protein is set, the remaining calories divide between carbs and fat by goal: roughly 42.5% carbs / 57.5% fat when losing, 50/50 maintaining, and 57.5% carbs / 42.5% fat gaining. These are starting points — the split can flex to your preference and training, as long as protein and total calories hold.

For weight change, total calories drive the direction — a deficit loses, a surplus gains, regardless of the exact split. Macros shape the quality of that change: adequate protein preserves muscle and controls hunger, and the carb/fat balance affects energy, performance, and fullness. Calories set whether the scale moves; macros influence how much of the change is fat versus muscle, and how sustainable the plan is.