TDEE Calculator

Which BMR equation does the TDEE calculator use?

Mifflin-St Jeor: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5 for men, and the same expression with −161 instead of +5 for women. It is one of several predictive equations, and it is an estimate for an average person of your size, not a measurement of your own metabolism.

What are the activity multipliers?

TDEE is BMR multiplied by 1.2 (sedentary), 1.375 (lightly active), 1.55 (moderately active), 1.725 (very active) or 1.9 (extra active). The choice is a self-assessment, and picking one level too high is the most common reason a calculated target overshoots real maintenance.

How is the calorie target for my goal set?

The goal is a fixed offset added to TDEE: −500 or −250 kcal for the two loss options, 0 for maintenance, and +250 or +500 kcal for the two gain options. It is not scaled to your body size, so the same −500 is a bigger share of the budget for a small person than for a large one.

How is the macro split calculated?

Protein is fixed at 2 g per kg of body weight, fat is 25% of target calories divided by 9 kcal per gram, and carbohydrates are whatever calories remain divided by 4 kcal per gram. Because protein is tied to weight rather than calories, a very low target can leave little or no room for carbohydrates, and the carb figure is floored at 0 g.

Where does the weekly weight change figure come from?

It is the daily offset times 7, divided by 7,700 kcal per kg of body weight change. A −500 kcal goal shows −0.45 kg per week and −250 shows −0.23 kg. This is a fixed-rule estimate; real weight change slows as you lose or shifts with water and adaptation, so use it as a rough expectation only.

What happens if my target is lower than my BMR?

The calculator still gives the numbers, and adds a note when the target falls below your estimated BMR. For example, a 50 kg, 155 cm, 50-year-old woman who is sedentary and picks −500 kcal gets 769 kcal against a BMR of 1,058 kcal. That is a prompt to choose a smaller deficit and speak with a doctor or dietitian, not a plan to follow.

What units and inputs does it accept?

Weight in kilograms, height in centimetres and age in years, with male or female selected for the equation. Empty or zero fields fall back to defaults of 70 kg, 175 cm and 30 years. It has no body-fat input, so it cannot adjust for very muscular or very lean builds, and it is not designed for children, pregnancy or medical conditions.