How Many Calories Should I Eat Per Day? TDEE Explained

Calorie targets are the foundation of any nutrition plan — whether your goal is weight loss, muscle gain, or simply maintaining your current weight. But "eat less and move more" is not actionable advice without knowing your actual numbers. This guide explains how to calculate your Total Daily Energy Expenditure (TDEE), set appropriate calorie targets, and understand what the numbers actually mean.

What Is BMR?

Your Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest — the energy required just to keep your heart beating, your lungs breathing, your organs functioning, and your body temperature regulated. Even lying perfectly still all day, you burn your BMR in calories.

The Mifflin-St Jeor equation is the most accurate formula for most people:

For a 35-year-old woman, 165cm tall, weighing 65kg: BMR = (10 × 65) + (6.25 × 165) − (5 × 35) − 161 = 650 + 1,031 − 175 − 161 = 1,345 calories/day.

What Is TDEE?

Total Daily Energy Expenditure (TDEE) is your BMR multiplied by an activity factor that accounts for how much you move throughout the day. This is the number of calories you burn in a typical day, and the number you need to eat to maintain your current weight.

• Sedentary (desk job, minimal exercise): BMR × 1.2
• Lightly active (light exercise 1–3 days/week): BMR × 1.375
• Moderately active (moderate exercise 3–5 days/week): BMR × 1.55
• Very active (hard exercise 6–7 days/week): BMR × 1.725
• Extra active (physical job + daily exercise): BMR × 1.9

For the woman above with a moderately active lifestyle: TDEE = 1,345 × 1.55 = 2,085 calories/day. This is her maintenance calorie level.

Setting Calorie Targets for Different Goals

For weight loss: Create a calorie deficit — consume less than your TDEE. A deficit of 500 calories per day produces approximately 1 pound (0.45kg) of weight loss per week. A 250 calorie deficit = ~0.5 lbs/week. A 750 calorie deficit = ~1.5 lbs/week.

Important safety thresholds: women should not go below 1,200 calories/day and men not below 1,500 calories/day without medical supervision. Extreme deficits cause muscle loss, metabolic adaptation, nutritional deficiencies, and are unsustainable.

For muscle gain: Consume slightly more than your TDEE. A surplus of 250–500 calories per day supports muscle growth while minimizing fat gain — this is called a "lean bulk." A larger surplus just adds more fat without proportionally more muscle.

For maintenance: Eat at your TDEE. This is harder than it sounds in practice, which is why tracking for 2–4 weeks to find your true maintenance level is often more accurate than the formula alone.

Why TDEE Formulas Are Estimates

The activity multipliers above are statistical averages. Individual variation is real and significant:

• Two people with identical stats can have BMRs differing by 200–300 calories due to genetics, muscle mass, and metabolic efficiency
• Activity level is frequently overestimated — most people are more sedentary than they think
• NEAT (Non-Exercise Activity Thermogenesis) — fidgeting, walking, casual movement — varies dramatically between individuals and accounts for 100–800 calories/day difference

The best approach: calculate your TDEE from the formula, track your calories for 2 weeks, and see what actually happens to your weight. Adjust based on real data rather than formula outputs.

Macronutrients Within Your Calorie Budget

Once you know your calorie target, distributing those calories across protein, carbohydrates, and fat matters. A general framework:

• Protein: 0.7–1.0g per pound of body weight (1.6–2.2g/kg). This is the most important macro — it preserves muscle during weight loss and supports muscle building during a surplus.
• Fat: At least 0.35g per pound of body weight (0.8g/kg). Fat supports hormones and fat-soluble vitamin absorption.
• Carbohydrates: Fill the remaining calories. Carbs fuel exercise performance and are the body's preferred energy source.

Key Takeaways

• BMR = calories burned at rest. TDEE = BMR × activity factor = daily maintenance calories
• The Mifflin-St Jeor equation is the most accurate BMR formula for most people
• 500 calorie deficit per day = approximately 1 lb weight loss per week
• 250–500 calorie surplus supports muscle gain with minimal fat accumulation
• Formulas are starting points — track and adjust based on your actual results