Daily Calorie Needs Calculator

Daily Calorie Needs Calculator estimates daily calorie requirements for weight maintenance, loss, or gain based on current weight, height, age, gender, activity level, goal weight, and time frame.

Enter values (leave goal weight and weeks blank for maintenance):

Current Weight (kg):

Height (cm):

Age (years):

Gender:

Activity Level:

Goal Weight (kg):

Time Frame (weeks):

Methodology Used in Daily Calorie Needs Calculator

The calculator estimates daily calorie needs using:

1. BMR (Mifflin-St Jeor): \\( \text{BMR} = 10 \cdot \text{Weight} + 6.25 \cdot \text{Height} – 5 \cdot \text{Age} + 5 \\) (men) or \\( -161 \\) (women)

2. TDEE: \\( \text{TDEE} = \text{BMR} \cdot \text{Activity Multiplier} \\)

3. Weight change: \\( \Delta W = |\text{Current Weight} – \text{Goal Weight}| \\)

4. Total calories: \\( C_{\text{total}} = \Delta W \cdot 7700 \\)

5. Daily adjustment: \\( C_{\text{adjust}} = \frac{C_{\text{total}}}{\text{Weeks} \cdot 7} \\) (deficit if loss, surplus if gain)

6. Daily calories: \\( C_{\text{daily}} = \text{TDEE} \pm C_{\text{adjust}} \\) (minus for loss, plus for gain)

Where:

\\( \text{BMR} \\): Basal Metabolic Rate (kcal/day)
\\( \text{TDEE} \\): Total Daily Energy Expenditure (kcal/day)
\\( \Delta W \\): Weight change (kg)
\\( C_{\text{total}} \\): Total calories for weight change (kcal)
\\( C_{\text{adjust}} \\): Daily surplus or deficit (kcal/day)
\\( C_{\text{daily}} \\): Daily calorie needs (kcal/day)

Assumes 7700 kcal/kg for weight change. Computes daily calories for goal.

Example Calculation (Weight Loss)

Sample Input

Current Weight = 80 kg, Height = 175 cm, Age = 30, Gender = Male, Activity Level = Moderate (1.55), Goal Weight = 75 kg, Weeks = 10

Step 1: BMR: \\( \text{BMR} = 10 \cdot 80 + 6.25 \cdot 175 – 5 \cdot 30 + 5 \approx 1750 \, \text{kcal/day} \\)

Step 2: TDEE: \\( \text{TDEE} = 1750 \cdot 1.55 \approx 2712.5 \, \text{kcal/day} \\)

Step 3: Weight loss: \\( \Delta W = 80 – 75 = 5 \, \text{kg} \\)

Step 4: Total calories: \\( C_{\text{total}} = 5 \cdot 7700 = 38500 \, \text{kcal} \\)

Step 5: Daily deficit: \\( C_{\text{deficit}} = \frac{38500}{10 \cdot 7} \approx 550 \, \text{kcal/day} \\)

Step 6: Daily calories: \\( C_{\text{daily}} = 2712.5 – 550 \approx 2162.5 \, \text{kcal/day} \\)

Result: Daily Calorie Needs = 2162.5 kcal/day for weight loss.