Macronutrient Balance Calculator
Calculate your ideal daily protein, carbohydrate, and fat intake based on your total daily energy expenditure (TDEE) and fitness goals.
Formulas Used
1. Basal Metabolic Rate (Mifflin-St Jeor):
Male: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5
Female: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161
2. Total Daily Energy Expenditure (TDEE):
TDEE = BMR × Activity Multiplier
3. Target Calories by Goal:
Cut: TDEE − 500 kcal | Maintain: TDEE | Bulk: TDEE + 300 kcal
4. Macronutrient Grams:
Protein (g) = (Target kcal × P%) ÷ 4 |
Carbs (g) = (Target kcal × C%) ÷ 4 |
Fat (g) = (Target kcal × F%) ÷ 9
Assumptions & References
- BMR calculated using the Mifflin-St Jeor equation (1990), considered the most accurate for most adults (Academy of Nutrition and Dietetics).
- Activity multipliers sourced from Harris-Benedict revised factors (Frankenfield et al., 2005).
- A deficit of 500 kcal/day targets ~0.45 kg/week fat loss (Hall et al., 2012, Lancet).
- A surplus of 300 kcal/day supports lean muscle gain while minimising fat accumulation.
- Caloric floor of 1,200 kcal/day applied to prevent unsafe restriction.
- Protein and carbohydrates provide 4 kcal/g; fat provides 9 kcal/g (Atwater factors).
- Optimal protein intake for active individuals: 1.6–2.2 g/kg/day (Morton et al., 2018, BJSM).
- Results are estimates. Individual metabolism, body composition, and health conditions vary. Consult a registered dietitian for personalised advice.