How Many Calories Should I Eat a Day?

"Eat 2,000 calories a day" is printed on food labels everywhere, but your real number could be 1,500 or 3,000. Here's how to work out the right target for your body and your goal.

Step 1: Your BMR

Your basal metabolic rate is the energy your body burns at complete rest, just to keep you alive: breathing, circulation, temperature and brain activity. It's usually the largest part of your daily calories.

The most widely recommended estimate 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: a 30-year-old man, 75 kg, 175 cm: 750 + 1,093.75 − 150 + 5 = 1,699 kcal.

Step 2: Add your activity

Multiply your BMR by an activity factor to estimate your total daily energy expenditure (TDEE):

For our example, lightly active: 1,699 × 1.375 ≈ 2,336 kcal a day to maintain his weight.

Be honest here: most people overestimate their activity.

Step 3: Adjust for your goal

• Lose weight: eat about 300–500 kcal below your TDEE. That's typically 0.25–0.5 kg a week, a pace most people can sustain.
• Maintain: eat around your TDEE.
• Gain muscle: eat about 200–300 kcal above your TDEE and do strength training.

Avoid crash diets. Very low intakes make it hard to get enough protein and nutrients and are difficult to keep up.

Why the numbers are estimates

Equations are based on averages. Your real needs depend on muscle mass, genetics, sleep, stress and more. Use your estimate as a starting point, track your weight for 2–3 weeks, and adjust by 100–200 kcal if it isn't moving the way you want.

What you eat matters too

Calories decide whether you gain or lose weight, but the makeup of your diet decides how you feel and what you lose:

• Protein helps keep muscle while dieting and keeps you full. Most active adults do well on 1.2–1.6 g per kg of body weight.
• Fibre from vegetables, fruit, lentils and whole grains helps with fullness.
• Liquid calories such as soft drinks, juices and sweet tea add up quickly without filling you up.

Calculate your numbers

The calorie calculator gives your daily targets for losing, maintaining or gaining weight. For just your resting burn, use the BMR calculator, and split your calories into protein, carbs and fat with the macro calculator.

This article is general information, not medical advice. If you're pregnant, have a medical condition or want to lose a lot of weight, talk to a doctor or dietitian.