Estimate how many calories you need each day to maintain, lose, or gain weight, based on your body and activity level.
This calculator uses the Mifflin-St Jeor equation to estimate your Basal Metabolic Rate (BMR), then multiplies it by an activity factor to estimate total daily energy expenditure.
A deficit of roughly 500 calories a day tends to produce about 0.5 kg of weight loss per week, since one kilogram of body fat corresponds to roughly 7,700 calories. The same logic in reverse applies to weight gain.
It's a well-validated estimate for most people, but individual metabolism varies. Use it as a starting point and adjust based on your actual weight trend over a few weeks.
Activity level scales your baseline metabolic rate to reflect real daily energy use — the difference between sedentary and very active can be 500+ calories a day.