Calorie and energy needs calculator

BMR is the energy your body would burn lying still all day: heartbeat, breathing, keeping warm, running your brain and organs. For most people that is roughly 60-70 percent of the total.

TDEE is your BMR plus everything you actually do: walking, work, training, digestion, even fidgeting in your chair. This is the number you plan your food around.

The result is an estimate, not a measurement. The equation knows nothing about your body composition, genetics, hormones or how much you move outside the gym. Two people with identical numbers on paper can differ by 200-300 kcal in real life. Treat it as a starting point, not a verdict.

Checking it is simple. Eat around the calculated figure for two to three weeks and weigh yourself in the morning, before eating, a few times a week. The weekly average is what counts, never a single reading. If your weight moves the way you planned, the number was right. If it stalls despite a deficit, adjust by 100-150 kcal, not by 500.

Do not automatically pick the lowest figure in the fat loss range. A bigger deficit does not buy faster results, it buys worse sleep, weaker sessions, more hunger and a much better chance of the whole thing falling apart in a few weeks.

Basal metabolic rate uses the Mifflin-St Jeor equation (1990), currently the most widely recommended one for the general population:

• men: 10 × weight [kg] + 6.25 × height [cm] - 5 × age + 5
• women: 10 × weight [kg] + 6.25 × height [cm] - 5 × age - 161

Total energy needs are your BMR multiplied by an activity factor:

• Very low (×1.2): Desk job, no training, little walking during the day.
• Low (×1.375): Desk job plus 1-2 easy sessions a week, or a lot of walking.
• Moderate (×1.55): Training 3-4 times a week plus normal daily activity.
• High (×1.725): Training 5-6 times a week, or physical work with training on top.
• Very high (×1.9): Hard training every day, twice a day, or heavy physical work.

Calories by goal: fat loss is 10-20 percent below TDEE, muscle gain is 8-12 percent above. The lower bound for fat loss never goes below your BMR, nor below 1200 kcal for women and 1500 kcal for men.

Macros: protein at 2 g per kilogram of body weight for fat loss and 1.8 g for maintenance and muscle gain, fat at 0.8 g and 1 g per kilogram respectively, with carbohydrates taking whatever calories are left. The conversions used are 4 kcal per gram of protein and carbohydrate, and 9 kcal per gram of fat. Protein never exceeds 40 percent of total calories, and fat never drops below 20 percent.

A woman, 35 years old, 168 cm, 70 kg, training 3-4 times a week (moderate activity).

1. BMR = 10 × 70 + 6.25 × 168 - 5 × 35 - 161 = 1,410 kcal
2. TDEE = 1,410 × 1.55 = 2,190 kcal
3. Fat loss = 1,750-1,970 kcal, muscle gain = 2,370-2,450 kcal
4. Macros for fat loss: 140 g protein, 56 g fat, 199 g carbohydrates

In practice I would start at the top of the range, around 1,970 kcal, and only go lower once weight stopped moving.

• Picking the lowest possible number. Hunger and fatigue are not a measure of progress. A deficit you cannot hold for a few months is worse than a smaller one you can.
• Overrating your activity level. Three sessions a week is moderate, not high. A desk job plus the gym three times a week is still a sedentary life for most of the day.
• Forgetting liquid calories. Coffee with milk and syrup, juice, beer and “just a splash” of oil in the pan can quietly add 300-500 kcal a day.
• Judging by a single weigh-in. Body weight swings 1-2 kg day to day from water, salt, your cycle and gut contents. Look at the weekly average.
• Not recalculating after losing weight. Once you are 5-6 kg lighter, your needs are lower. Come back and run the numbers again.
• Counting calories without strength training. A deficit on its own takes both fat and muscle. Lifting is the signal that tells your body to keep the muscle.

If you live in Kraków and prefer training in person, I coach complete beginners, people who want to lose weight and people coming back to activity after a break. The studio is small and private, at Zawiła 61A where Ruczaj meets Kliny, so nobody trains in a crowd or under anyone's gaze.

During a free consultation we go through your result from this calculator, your weight history and a realistic plan. Have a look at 1:1 personal training or online coaching.