Macronutrient Ratio Calculator
Macronutrient Ratio Calculator determines daily carbohydrate, protein, and fat intake (grams) for weight loss or gain, based on current weight, goal weight, time frame, activity level, height, age, gender, and optional macronutrient ratios.
Enter values (leave ratio fields blank for default 45:25:30):
Methodology Used in Macronutrient Ratio Calculator
The calculator estimates daily carbohydrate, protein, and fat intake using:
1. Weight change: \\( \Delta W = |\text{Current Weight} – \text{Goal Weight}| \\)
2. Total calories: \\( C_{\text{total}} = \Delta W \cdot 7700 \\)
3. Daily adjustment: \\( C_{\text{adjust}} = \frac{C_{\text{total}}}{\text{Weeks} \cdot 7} \\) (deficit if loss, surplus if gain)
4. BMR (Mifflin-St Jeor): \\( \text{BMR} = 10 \cdot \text{Weight} + 6.25 \cdot \text{Height} – 5 \cdot \text{Age} + 5 \\) (men) or \\( -161 \\) (women)
5. TDEE: \\( \text{TDEE} = \text{BMR} \cdot \text{Activity Multiplier} \\)
6. Total daily calories: \\( C_{\text{daily}} = \text{TDEE} \pm C_{\text{adjust}} \\) (minus for loss, plus for gain)
7. Macronutrient intake:
\\( \text{Carbs} = \frac{C_{\text{daily}} \cdot \text{Carb Ratio}}{4} \\), \\( \text{Protein} = \frac{C_{\text{daily}} \cdot \text{Protein Ratio}}{4} \\), \\( \text{Fat} = \frac{C_{\text{daily}} \cdot \text{Fat Ratio}}{9} \\)
Where:
- \\( \Delta W \\): Weight change (kg)
- \\( C_{\text{total}} \\): Total calories for weight change (kcal)
- \\( C_{\text{adjust}} \\): Daily surplus or deficit (kcal/day)
- \\( \text{BMR} \\): Basal Metabolic Rate (kcal/day)
- \\( \text{TDEE} \\): Total Daily Energy Expenditure (kcal/day)
- Carb/Protein/Fat Ratio: Percentage of total calories (default 45:25:30)
Assumes 4 kcal/g for carbs/protein, 9 kcal/g for fat. Computes macronutrient intake.
Example Calculation (Weight Loss)
Sample Input
Current Weight = 80 kg, Goal Weight = 75 kg, Weeks = 10, Activity Level = Moderate (1.55), Height = 175 cm, Age = 30, Gender = Male, Ratios = 45:25:30
Step 1: Weight loss: \\( \Delta W = 80 – 75 = 5 \, \text{kg} \\)
Step 2: Total calories: \\( C_{\text{total}} = 5 \cdot 7700 = 38500 \, \text{kcal} \\)
Step 3: Daily deficit: \\( C_{\text{deficit}} = \frac{38500}{10 \cdot 7} \approx 550 \, \text{kcal/day} \\)
Step 4: BMR: \\( \text{BMR} = 10 \cdot 80 + 6.25 \cdot 175 – 5 \cdot 30 + 5 \approx 1750 \, \text{kcal/day} \\)
Step 5: TDEE: \\( \text{TDEE} = 1750 \cdot 1.55 \approx 2712.5 \, \text{kcal/day} \\)
Step 6: Daily calories: \\( C_{\text{daily}} = 2712.5 – 550 \approx 2162.5 \, \text{kcal/day} \\)
Step 7: Macronutrient intake:
Carbs: \\( \frac{2162.5 \cdot 0.45}{4} \approx 243.28 \, \text{g/day} \\)
Protein: \\( \frac{2162.5 \cdot 0.25}{4} \approx 135.16 \, \text{g/day} \\)
Fat: \\( \frac{2162.5 \cdot 0.30}{9} \approx 72.08 \, \text{g/day} \\)
Result: Carbs = 243.28 g/day, Protein = 135.16 g/day, Fat = 72.08 g/day.