Enter your details to calculate your BMR (Basal Metabolic Rate) and TDEE (Total Daily Energy Expenditure):
What is BMR ?
BMR (Basal Metabolic Rate) is the number of calories your body needs to maintain basic physiological functions at rest.
Mifflin-St Jeor Formula:
- For men: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5
- For women: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161
What is TDEE ?
TDEE (Total Daily Energy Expenditure) is the total calories your body burns in a day, including:
- BMR (basal metabolic rate — energy for basic functions)
- NEAT (non-exercise activity, like walking, fidgeting)
- Exercise
- Thermic Effect of Food (digesting and processing food)
TDEE = BMR × Activity Level
Activity Level
Activity level is a factor that is based on the amount of activity a person undergoes. This includes deliberate exercise as well as other activities that a person may undergo as part of their job or typical daily activities.
These factors are more specifically referred to as the thermic effect of activity, and non-exercise activity thermogenesis (energy expended for non-sleeping, eating, or sports-like exercise).
- Sedentary (little or no exercise) =1.2
- Lightly active (light exercise 1–3 days/week)=1.375
- Moderately active (moderate exercise 3–5 days/week)=1.55
- Very active (hard exercise 6–7 days/week)=1.725
- Extra active (very intense daily exercise or physical job)=1.9
What is Thermic Effect of Food ?
The Thermic Effect of Food (TEF) is the amount of energy (calories) your body uses to digest, absorb, and process the nutrients from the food you eat.
When you eat:
- Chewing and swallowing require a tiny bit of energy.
- Digesting food in the stomach and intestines uses enzymes and muscles — this costs energy.
- Absorbing nutrients into the bloodstream takes more work.
- Metabolizing nutrients (turning them into usable energy or storing them) also burns calories.
Different macronutrients have different TEF values: Protein~20–30% (highest), Carbs~5–10%, Fat~0–3% (lowest).
This is one reason high-protein diets can help with fat loss — protein burns more calories during digestion, helps preserve muscle, and keeps you fuller for longer.
The common BMR × Activity Level shortcut comes from the Harris-Benedict method. The “Activity Level” multiplier (e.g., 1.2, 1.375, 1.55…) is actually based on studies that already bake TEF into those numbers along with exercise and NEAT.
Example:
- Sedentary = 1.2 (includes BMR + minimal NEAT + TEF)
- Lightly active = 1.375 (includes BMR + some NEAT + TEF + some exercise)
So, TEF isn’t missing — it’s just lumped into the activity multiplier instead of being shown separately.
What is Calorie Deficit ?
A calorie deficit is when you consume fewer calories than your body burns in a day.
Calorie Deficit = TDEE − Calories Consumed
To lose fat, you eat fewer calories than your TDEE.
- Small deficit (~300–500 kcal/day) → slower but sustainable fat loss, minimal muscle loss.
- Large deficit (>700–1,000 kcal/day) → faster loss but higher risk of fatigue, nutrient deficiencies, and muscle loss.
Example:
- TDEE = 2,200 kcal
- Eat = 1,700 kcal
- Deficit = 500 kcal/day
- Potential fat loss ≈ 0.45 kg/week (about 1 lb)
If your calorie deficit is greater than 1,000 kcal/day, your body will lose weight faster, but it comes with some important trade-offs such as Higher muscle loss risk, Metabolic slowdown,Hormonal changes, Nutrient deficiencies and Sustainability issues.
Most health and sports nutrition bodies (e.g., ACSM) recommend:
- 300–700 kcal/day deficit for sustainable fat loss.
- This equals ~0.25–0.75 kg per week for most people.
Going beyond a 1,000 kcal/day deficit is generally not recommended unless under professional supervision.
Note: These calculations are estimates. Individual calorie needs can vary based on genetics, muscle mass, metabolism, and health conditions.
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