How many calories should I eat per day
How many calories you should eat per day depends on several factors: your current weight, height, age, biological sex and — above all — your daily activity level and your goal (lose, maintain or gain).
For most people there is no magic universal figure of 2,000 calories. A small, sedentary woman may need only 1,500 kcal, while a tall, very active man may need more than 3,000 kcal. That is why it is essential to use a personalized calculator that accounts for your physiology.
How we calculate your target
We use a scientific method in three steps:
1. First we calculate your Basal Metabolic Rate (BMR) using the Mifflin-St Jeor equation, which estimates the energy your body spends simply staying alive (breathing, circulation and so on). 2. Then we multiply your BMR by your activity factor (sedentary, light, moderate or intense) to find your Total Daily Energy Expenditure (TDEE). 3. Finally we adjust that figure to your goal. To lose weight we apply a 20% deficit. To maintain, we keep the TDEE as is. To gain, we apply a 10% surplus.
Calories to lose, maintain or gain
• To lose weight: the golden rule is a sustainable calorie deficit. We recommend cutting 20% from your daily burn. That delivers healthy weight loss without sacrificing muscle mass or leaving you hungry all the time. One caveat: we never suggest eating below the safety floor (1,500 kcal for men, 1,200 kcal for women). • To maintain: ideal if you are already at your target weight, or if you want to focus on body recomposition (trading fat for muscle) at a slow pace. • To gain: to build muscle (hypertrophy) you need a slight calorie surplus (around 10%) combined with strength training. Much more than that and the gain will be mostly fat.
Why calorie counting works (and how to make it easy)
Whatever the diet of the moment — low carb, intermittent fasting, keto — the only biological reason it produces weight loss is that it creates a calorie deficit by the end of the day. Once you understand and track your calories, you get the freedom to eat the foods you enjoy, as long as they fit your daily target.
The worst part of counting calories has always been weighing every ingredient and digging through enormous databases. Nutricalor solves that with AI: you just take a photo of your plate, and the AI estimates the calories and macronutrients automatically — reading a full, mixed plate rather than a single labeled product.
Frequently asked questions
- Does the calorie target already include the exercise I do?
- Yes. The activity level you select already multiplies your basal rate to account for exercise. If you selected 'Moderate' or 'Intense', you do not need to add the calories burned in training separately — they are already in the figure.
- Can I eat below 1,200 (women) or 1,500 (men) calories to speed things up?
- It is not recommended. Very low calorie diets (VLCD) can cause severe muscle loss, vitamin deficiency, extreme fatigue and hair loss. On top of that, when the diet ends, a slowed metabolism makes rapid weight regain more likely (the yo-yo effect).
- If I hit my calories, does it matter what I eat?
- For the raw number on the scale, calorie quantity is the dominant factor. But for the quality of that weight (muscle vs fat), for satiety, health and energy, where those calories come from matters a great deal. You need enough protein, good fats, vitamins and fiber.
- How do I know whether to focus on losing fat or building muscle?
- If your body fat percentage is high and it bothers you, losing fat should be the primary focus. If you are new to strength training, you can often build muscle and lose fat at the same time (body recomposition) by eating at maintenance or in a light deficit.
- Does this calculator work for children and teenagers?
- No. This calculator (the Mifflin-St Jeor equation) has been validated only for adults (18 and over). Children and teenagers are still growing and have different metabolic needs, requiring pediatric or dietitian supervision.