Calorie Calculator

This tool uses the Mifflin-St Jeor equation, which most dietitians and researchers consider the most reliable formula for estimating calorie needs in the general population. That said, it's still an estimate — actual metabolism varies based on muscle mass, genetics, hormone levels, and other individual factors that a simple formula can't capture. Treat the result as a solid starting point, then adjust based on how your weight actually changes over a few weeks.

BMR (Basal Metabolic Rate) is the energy your body burns at complete rest just to keep your organs running — breathing, circulating blood, maintaining body temperature. TDEE (Total Daily Energy Expenditure) takes that number and multiplies it by an activity factor to estimate how much you burn across a full day, including exercise, walking, fidgeting, and digestion. TDEE is the number that matters for setting a calorie target, since it reflects your actual day-to-day burn.

Not necessarily. These numbers work best as weekly averages rather than a strict daily rule. Your calorie needs naturally fluctuate with sleep, stress, and activity, so eating a bit above or below the target on any given day is normal and expected. What matters more is the trend over two to three weeks.

As you lose or gain weight, your BMR shifts because a lighter or heavier body needs more or less energy to maintain itself. Age, muscle mass, and activity level also change over months and years. It's worth recalculating every few weeks if you're actively trying to lose or gain weight, rather than using one number indefinitely.

Conditions like thyroid disorders, PCOS, or certain medications can meaningfully shift calorie needs above or below what a standard formula predicts. If you have a diagnosed condition affecting metabolism, or you're on medication that affects weight, it's worth working with a doctor or registered dietitian to set a target rather than relying solely on this calculator.