Start with your TDEE and add 250-500 calories for a lean bulk. Track weight weekly — aim for 0.5-1 lb gain per week. If gaining faster, reduce calories slightly. If not gaining, increase by 100-200 calories. Protein should be at least 1g per pound of body weight.

Subtract 500-750 calories from your TDEE for a moderate cut. Keep protein high (1.0-1.2g per pound) to preserve muscle. Reduce calories from carbs and fats, not protein. Aim to lose 0.5-1% of body weight per week to minimize muscle loss.

Both matter. Total calories determine whether you gain or lose weight, while macro ratios affect body composition. High protein (1g/lb) preserves muscle during cuts and supports growth during bulks. Carbs fuel training performance, and fats support hormonal health.