How to Calculate Your Daily Calorie Needs
Your daily calorie needs depend on how much energy your body burns at rest (BMR) plus how much you burn through activity. Get this number right and you have the foundation for any nutrition goal — weight loss, maintenance, or muscle gain.
Step 1: Calculate Your BMR
BMR (Basal Metabolic Rate) is the calories your body burns at complete rest — just to keep organs functioning. The most accurate widely-used formula is the Mifflin-St Jeor equation:
Men: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) + 5
Women: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) − 161
Example (30-year-old man, 180 lbs / 82 kg, 5'11" / 180 cm):
BMR = (10 × 82) + (6.25 × 180) − (5 × 30) + 5 = 820 + 1125 − 150 + 5 = 1,800 calories/day
Use our BMR Calculator to get your number instantly.
Step 2: Apply an Activity Multiplier (TDEE)
TDEE (Total Daily Energy Expenditure) = BMR × activity multiplier:
- Sedentary (desk job, little exercise): × 1.2
- Lightly active (exercise 1–3 days/week): × 1.375
- Moderately active (exercise 3–5 days/week): × 1.55
- Very active (hard exercise 6–7 days/week): × 1.725
- Extra active (physical job + daily training): × 1.9
Continuing the example above (moderately active): 1,800 × 1.55 = 2,790 calories/day to maintain weight
Step 3: Adjust for Your Goal
- Weight loss: Subtract 300–500 calories from TDEE. A 500-calorie daily deficit = ~1 lb/week loss.
- Maintenance: Eat at TDEE.
- Muscle gain: Add 200–300 calories to TDEE (lean bulk) or 300–500 (standard bulk).
Don't cut more than 1,000 calories below TDEE — aggressive deficits lead to muscle loss, fatigue, and rebound weight gain. Slower is more sustainable.
Why These Are Estimates
All BMR formulas are population averages. Individual metabolism varies by 15–20% due to genetics, hormones, muscle mass, and gut microbiome. Treat your calculated TDEE as a starting point — track actual weight changes over 2–3 weeks and adjust intake by 100–200 calories if you're not moving toward your goal at the expected rate.