CALORIE CALCULATOR
Estimate BMR, TDEE, and a fixed example macronutrient split for adults
YOUR DAILY CALORIE NEEDS
MACRONUTRIENT DISTRIBUTION
How the Calorie Estimate Is Calculated
The calculator estimates resting energy expenditure with the Mifflin–St Jeor equation. Weight is converted to kilograms and height is converted to centimeters before the equation is applied.
Male: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5
Female: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161
Activity Multipliers
| Activity level | Multiplier |
|---|---|
| Sedentary | 1.200 |
| Lightly active | 1.375 |
| Moderately active | 1.550 |
| Very active | 1.725 |
| Extremely active | 1.900 |
Total daily energy expenditure is calculated as BMR × activity multiplier. Activity categories are broad estimates rather than direct measurements of energy use.
Calorie Adjustments
| Selected goal | Adjustment from estimated TDEE |
|---|---|
| Maintain weight | 0 kcal/day |
| Lose about 0.25 kg/week | −250 kcal/day |
| Lose about 0.5 kg/week | −500 kcal/day |
| Gain about 0.25 kg/week | +250 kcal/day |
| Gain about 0.5 kg/week | +500 kcal/day |
The weekly weight-change descriptions are approximate. Actual changes may differ because energy expenditure and body weight do not change in a perfectly linear manner.
Minimum Displayed Calorie Level
The calculator does not display a target below 1,200 kcal/day for women or 1,500 kcal/day for men. These limits are screening safeguards, not individualized medical recommendations. A lower-calorie diet requires assessment and monitoring by a qualified healthcare professional.
Macronutrient Calculation
Macronutrients are shown with a fixed example split of 30% protein, 50% carbohydrate, and 20% fat. Protein and carbohydrate are converted at 4 kcal per gram; fat is converted at 9 kcal per gram.
The fixed split is not based on age, training type, medical history, food preferences, or an individual protein requirement. It sits within the adult Acceptable Macronutrient Distribution Ranges: 10–35% protein, 45–65% carbohydrate, and 20–35% fat.
Scope and Limitations
The calculator is limited to adults aged 18–80. It is not designed for children or adolescents, pregnancy, breastfeeding, eating disorders, competitive athletic nutrition, or medical conditions that affect metabolism, fluid balance, kidney function, liver function, blood glucose, or nutrient requirements.
Calculated BMR, TDEE, calorie targets, and macronutrient values are estimates. Individual needs can differ because of body composition, genetics, medication, illness, sleep, temperature, training load, and measurement error.
Sources
- Mifflin MD et al. “A new predictive equation for resting energy expenditure in healthy individuals.” American Journal of Clinical Nutrition, 1990.
- National Academies of Sciences, Engineering, and Medicine. Acceptable Macronutrient Distribution Ranges for adults.
- National Heart, Lung, and Blood Institute. Clinical guidance on reduced-calorie eating plans.
