How does the Calorie Calculator work?
The basal rate uses Mifflin-St Jeor: 10·kg + 6.25·cm − 5·age + s (s = +5 for men, −161 for women). Daily needs (TDEE) = basal rate × activity factor (1.2 to 1.9).
Background & details
How to read the four values
The calculator shows you four numbers. The basal rate (BMR) is what your body burns lying still – the absolute floor you should not sit below long-term. Daily needs (TDEE) is your maintenance level including movement. The lose weight line is maintenance minus 500 kcal, the gain weight line plus 500 kcal. Eat at maintenance and your weight holds steady.
What values are realistic?
- A moderate deficit of 300–500 kcal/day suits most people: noticeable progress without constant hunger.
- A surplus of 250–500 kcal/day is enough for clean muscle gain – more tends to end up as fat.
- Aggressive diets with a 1,000+ kcal deficit cost muscle and energy and usually end in yo-yo regain.
Common mistakes
The most common mistake is setting the activity factor too high. Three easy workouts a week is "lightly active" (1.375), not "very active". Overstate it and you get an inflated TDEE and fail to lose despite a supposed deficit. The second classic: drinks, cooking oil and small snacks go uncounted – a single tablespoon of oil is already about 90 kcal. And remember the TDEE is an estimate with roughly ±10 % margin, not an exact measurement.
Practical tips
Treat the number as a starting point, not a law. Eat at the calculated deficit for two to three weeks and weigh yourself in the morning. If nothing moves, cut another 150–200 kcal. If you lose more than 1 kg a week, eat a little more – losing too fast eats into muscle. While cutting, keep protein high (around 1.6–2 g per kg of body weight); it protects muscle and keeps you fuller for longer.
When to update the number
Your needs are not fixed. With every kilo lost the TDEE drops slightly, because a lighter body burns less. So recalculate every four to six weeks. Also update it when you train more, fall ill, or take a diet break, rather than running on the old figure for months.