Weight Gain Calorie Calculator
Calculates caloric surplus requirements for muscle hypertrophy or mass gain. Features clean vs. dirty bulk projections and high-density food suggestions.
About
Successfully increasing body mass requires a sustained caloric surplus where energy intake exceeds Total Daily Energy Expenditure (TDEE). This tool is engineered for individuals struggling to gain weight ("hard gainers") or athletes in a hypertrophy phase. The calculation differentiates between a "Clean Bulk" (minimal fat gain, slower pace) and a "Dirty Bulk" (maximum mass accumulation, higher fat risk).
The mathematical model computes the time horizon required to reach a specific target weight based on the surplus magnitude. Since adipose tissue and lean muscle mass have different energetic densities, the tool assumes a standard conversion rate of approximately 3,500 kcal per pound of tissue gained, though strictly lean mass synthesis is more metabolically complex.
Formulas
The baseline expenditure is derived from the Mifflin-St Jeor equation. The Target Daily Intake I is:
Where Δ represents the surplus. Time to goal t (in weeks) is estimated by:
This assumes a linear weight accumulation model where 1 lb ≈ 3500 kcal.
Reference Data
| Food Item | Serving Size | Calories (kcal) | Macro Focus |
|---|---|---|---|
| Peanut Butter | 2 tbsp | 190 | Fats/Protein |
| Olive Oil | 1 tbsp | 120 | Pure Fats |
| Walnuts | 1 oz (28g) | 185 | Omega-3s |
| Avocado | 1 medium | 320 | Fiber/Fats |
| Whole Milk | 1 cup | 150 | Protein/Calc |
| Oats (Dry) | 0.5 cup | 150 | Carbs |
| Dark Chocolate (85%) | 1 oz | 170 | Fats |
| Ground Beef (80/20) | 4 oz | 290 | Protein/Fats |