How Tabeku calculates your calories: the formulas behind your daily target

When an app tells you that your target is 2,180 kcal per day, it is fair to ask where that number comes from. At Tabeku, we do not treat it as a magic number: we calculate it from a physiological estimate, your activity level, and the goal you want to pursue.

The key idea is that maintenance calories are not a medical prescription or a perfect truth. They are a reasonable starting point. From there, your real weight trend, energy, and consistency help you adjust.

1. First we estimate your basal metabolic rate (BMR)

Basal metabolic rate, or BMR, is the energy your body needs at rest: breathing, maintaining temperature, supporting organs, repairing tissue, and keeping your brain running.

We estimate it with the Mifflin-St Jeor equation, one of the most commonly used nutrition formulas because it tends to perform better than older equations for the general population.

Formula for men

BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5

Formula for women

BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161

Two people with the same weight can get different targets if their height, age, or selected biological sex differ. That is why we use your data instead of copying a generic chart.

2. Then we apply your activity level

BMR only describes resting expenditure. To estimate your total daily energy expenditure, or TDEE, we multiply BMR by an activity factor:

Activity level	Multiplier
Sedentary	1.20
Slightly active	1.375
Moderately active	1.55
Active	1.725
Very active	1.90

Choosing the right category matters because activity level is one of the easiest things to overestimate. As a practical guide:

• Sedentary: you spend most of the day sitting, take few steps, and do not train regularly. This is common for office work without a workout routine.
• Slightly active: you walk often or train lightly 1-2 days per week, but your daily routine is still fairly calm.
• Moderately active: you train 3-4 days per week or combine regular exercise with a reasonable amount of daily steps.
• Active: you do intense training 5-6 days per week, have a physically active job, or accumulate a lot of weekly movement.
• Very active: best for athletes, double training sessions, hard physical jobs, or people who combine demanding workouts with many hours of movement.

If you are between two levels, it is usually better to start with the lower one and adjust later based on your weight trend and energy. A few consistent weeks tell you more than trying to guess perfectly on day one.

The formula is:

TDEE = BMR × activity multiplier

This step answers a practical question: how much energy do you burn on a normal day, not only while lying still in a lab?

3. We adjust for your goal

Once maintenance is estimated, Tabeku applies a simple, sustainable adjustment:

• Lose weight: calories = TDEE × 0.80
• Maintain weight: calories = TDEE × 1.00
• Gain weight: calories = TDEE × 1.10

In practice, the weight-loss target creates an approximate 20% deficit from maintenance calories. That is enough to generate progress, but not so aggressive that it unnecessarily increases hunger, hurts performance, or makes the diet hard to sustain.

For weight gain, we use an approximate 10% surplus. The goal is to provide extra energy to support muscle gain without turning the process into a fast and unnecessary increase in body fat. When bulking, more calories do not always mean better results: a controlled, measurable margin usually works better.

For maintenance, the multiplier stays at 1.00 because the goal is not to force weight up or down. It gives you a stable reference while you improve habits, food quality, or performance.

We use percentages instead of a fixed number because a 500 kcal reduction does not mean the same thing for someone maintaining at 1,700 kcal as it does for someone maintaining at 3,200 kcal. Percentages scale better with body size and activity.

4. We turn calories into macros

Calories tell you the total amount of energy. Macros explain where that energy comes from and how it may affect satiety, performance, and body composition.

In Tabeku’s calculator, we use this initial split:

Goal	Protein	Carbs	Fat
Lose weight	35%	35%	30%
Maintain	25%	45%	30%
Gain weight	25%	50%	25%

Then we convert calories into grams using standard energy values:

• Protein: 4 kcal per gram
• Carbs: 4 kcal per gram
• Fat: 9 kcal per gram

For example, if your weight-loss target were 2,000 kcal, protein would be about (2,000 × 0.35) / 4 = 175 g.

5. Why we still call it an estimate

No formula knows your real metabolism with perfect precision. Sleep, stress, menstrual cycle, muscle mass, digestion, daily steps, and adherence all change the real-world result.

That is why Tabeku uses these formulas as a transparent starting point. The important part is not hitting a perfect number on day one; it is having a reasonable baseline, tracking with low friction, and watching the trend over several weeks.

Try the calculator

Enter your details below and you will see how the formula becomes a daily target with calories and macros. If the result does not match exactly what you expected, remember: it is a compass, not a sentence.