Your body burns calories even when you are resting, and more when you move. Estimating your daily needs gives you a realistic starting point, whether your goal is to lose weight, maintain it, or build muscle.
Step 1: Find your BMR
Basal Metabolic Rate (BMR) is the energy your body uses at rest. A widely used estimate is the Mifflin-St Jeor equation:
- Men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
- Women: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161
Step 2: Multiply by your activity level
- Sedentary (little or no exercise): × 1.2
- Lightly active (1-3 days per week): × 1.375
- Moderately active (3-5 days per week): × 1.55
- Very active (6-7 days per week): × 1.725
- Extra active (physical job plus training): × 1.9
The result is your TDEE (Total Daily Energy Expenditure), the calories you need to maintain your current weight.
A worked example
A 30-year-old woman, 65 kg, 165 cm, moderately active:
- BMR = 650 + 1,031 − 150 − 161 = 1,370 calories
- TDEE = 1,370 × 1.55 = about 2,124 calories per day
A 30-year-old man, 80 kg, 180 cm, moderately active:
- BMR = 800 + 1,125 − 150 + 5 = 1,780 calories
- TDEE = 1,780 × 1.55 = about 2,759 calories per day
Adjusting for your goal
- Maintain weight: eat around your TDEE.
- Lose weight gradually: a modest deficit of roughly 300-500 calories below TDEE is a common starting point, which often leads to around 0.25-0.5 kg (0.5-1 lb) per week.
- Gain muscle: a small surplus of roughly 200-300 calories, combined with strength training.
Extreme cutting is not necessary and can backfire through lost muscle, low energy, and rebound eating.
Let a calculator do the work
Enter your age, height, weight, and activity level into a calorie calculator for an instant estimate. If you want to see each part separately, try a BMR calculator or a TDEE calculator. Once you know your calories, a macro calculator can help you split them into protein, carbs, and fat.
Keep in mind
- These are estimates. Your real needs can differ by 10% or more.
- Track your weight and energy for 2-3 weeks, then adjust.
- Food quality, sleep, and stress affect how you feel at any calorie level.
This article is for general information only and is not medical advice. Please consult a doctor or registered dietitian for personal guidance, especially if you have a health condition.
