In short:
- First calculate your BMR with the Mifflin–St Jeor equation, multiply it by an activity factor, and you get your TDEE — your daily energy expenditure.
- Set calories by goal: TDEE minus 400–500 kcal for fat loss, TDEE for maintenance, plus 200–300 kcal for mass gain.
- Macros: protein 1.6–2.2 g/kg, fat 0.8–1.2 g/kg, and fill the remaining calories with carbohydrates.
No supplement stack can make up for poor nutrition — calories and macronutrients are the foundation everything else is built on. If you want to lose fat, build muscle or maintain your current shape, it pays to know your numbers. In this guide we go step by step through how to calculate TDEE and macros, without starving yourself or falling for marketing myths.
How do you calculate TDEE and macros step by step?
The whole calculation starts with your basal metabolic rate (BMR) — the energy your body burns at complete rest. For healthy adults, the most accurate formula is Mifflin–St Jeor:
- 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
Once you have your BMR, you get your TDEE (total daily energy expenditure) by multiplying BMR by an activity factor:
- Sedentary lifestyle (office job, no training): 1.2
- Light activity (1–2 workouts per week): 1.375
- Moderate activity (3–4 workouts per week): 1.55
- High activity (5–6 workouts + physical job): 1.725
Example: a 30-year-old man, 80 kg and 180 cm, who trains four times a week. BMR = (10 × 80) + (6.25 × 180) − (5 × 30) + 5 = 1,780 kcal. TDEE = 1,780 × 1.55 ≈ 2,759 kcal. That is the amount of calories at which his body weight stays stable.
How do you set calories and macros for your goal?
Once you know your TDEE, adjust your calories to your goal:
- Fat loss: TDEE − 400–500 kcal. This gives about 0.5 kg of fat loss per week while preserving muscle. Avoid an aggressive deficit of more than 500 kcal — it speeds up muscle mass loss and slows your metabolism.
- Maintenance / recomposition: eat at TDEE.
- Mass gain: TDEE + 200–300 kcal, so that muscle grows with minimal fat gain.
Next, divide your calories into macronutrients. A practical starting point:
- Protein: 1.6–2.2 g per kg of body weight (4 kcal/g).
- Fat: 0.8–1.2 g/kg (9 kcal/g) — needed for hormones and for vitamin absorption, so there is no reason to fear it.
- Carbohydrates: divide the remaining calories by 4 (4 kcal/g).
Why calories are the foundation of everything is explained in depth in the article More than calories, and you can find out why food quality matters, not just the number, in the article Are all calories created equal.
How much protein do you actually need?
Protein is the building material of muscle and the most important macronutrient both during fat loss and during muscle growth. A meta-analysis of 49 studies (Morton et al., 2018) found that 1.6–2.2 g of protein per kg of body weight per day is the optimal range for muscle growth and retention — more than that gives no additional benefit. For a person weighing 80 kg, that means about 128–176 g of protein per day.
Timing is secondary: the old myth of the “anabolic window” has been debunked, because total daily protein matters more than the exact time of day. A practical recommendation is to spread your protein across 3–5 meals, about 30–50 g each, to support muscle protein synthesis evenly throughout the day. To see how protein works together with calories to support muscle growth, read the article How to build quality muscle I.
These numbers are a good starting point, but individual response varies. The general principles of balanced nutrition are described in the Estonian national nutrition recommendations (TAI). If you have a chronic condition or take medication, consult a doctor or dietitian before starting a strict diet.
How do you use the calculation in practice?
Your calculated TDEE and macros aren’t set in stone — they are a starting point that you adjust based on your actual results. The most honest feedback is change over time: weigh yourself several times a week in the morning, fasted, and take the average, because water, glycogen and time of day fluctuate from day to day. If your weight doesn’t move for two to three weeks during fat loss, reduce your calories by about 100–200 kcal or add more movement; if you are gaining too much fat during mass gain, take your carbohydrates down a little.
A few practical rules keep the numbers working: eat protein at every meal, concentrate the bulk of your carbohydrates around training, eat at least 400 g of vegetables a day for dietary fiber and micronutrients, and drink enough water, because even mild dehydration reduces strength. Consistency over weeks matters more than any single perfect day — sticking to 80% of the plan over the long term beats 100% for a short time.
References
- Morton RW et al. (2018). The effect of protein supplementation on muscle mass and strength — a meta-analysis of 49 studies.
- Mifflin MD, St Jeor ST et al. A formula for estimating resting energy expenditure in healthy adults.
- TAI / National Institute for Health Development — Estonian nutrition and physical activity recommendations (toitumine.ee).
- Fitness.ee workbook “Getting ready for summer: an 8-week plan” — chapter on calories and macros.
Frequently asked questions
What is the difference between BMR and TDEE?
BMR is the energy your body burns at complete rest. TDEE is your total daily energy expenditure, which also includes movement and training — you get it by multiplying your BMR by an activity factor (1.2–1.725).
How big should the calorie deficit be for fat loss?
The optimal deficit is TDEE minus 400–500 kcal, which gives about 0.5 kg of fat loss per week while preserving muscle. It’s worth avoiding a deficit larger than 500 kcal, because it promotes loss of muscle mass and strength.
How do you calculate your carbohydrate intake?
First set your protein and fat in grams and convert them into calories (protein and carbohydrates 4 kcal/g, fat 9 kcal/g). Subtract these from your target calories and divide the remainder by 4 — that is your carbohydrate grams.
Do I need to count macros exactly every day?
At first, tracking for a couple of weeks helps you calibrate your portion sizes and your eye. In the long run, what matters most is your total daily calories and enough protein — small day-to-day fluctuations don’t matter.
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