Calorie Calculator

Subtract 500 from your TDEE and you'll get a reasonable weight-loss target — this creates a deficit that should produce around 0.5 kg (1 lb) of fat loss per week. A more conservative deficit of 250 calories per day gives about half that rate but is generally easier to stick to and causes less muscle loss. The key thing to know is that your TDEE isn't fixed: as you lose weight, your BMR drops because you're carrying less mass, so you'll likely need to recalculate every 4 to 6 weeks rather than sticking with your original number forever.

BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest — think of it as the energy cost of staying alive. TDEE (Total Daily Energy Expenditure) adds everything on top of that: the energy you burn digesting food, walking to your car, exercising, fidgeting, working. For most people TDEE runs about 1.2 to 1.9 times their BMR depending on how active they are. When people talk about "how many calories should I eat," they mean their TDEE — that's the number that matters for day-to-day eating decisions.

Different calculators use different underlying equations (Mifflin-St Jeor, Harris-Benedict, Katch-McArdle, etc.), and they may define activity levels slightly differently. You'll commonly see a range of 100 to 200 calories between calculators for the same inputs — that's normal. All these formulas are estimates based on population averages, not precise measurements of your individual metabolism. The only way to know your true TDEE is to track calories carefully for a few weeks and see whether your weight is stable, rising, or falling.

In the short term it will, but it tends to backfire. Very low calorie intakes — especially below 1200 calories for women or 1500 for men — are hard to sustain, often lack the protein and nutrients needed to preserve muscle, and can trigger metabolic adaptation where your body deliberately slows down energy expenditure. The result is usually rapid initial loss followed by a stubborn plateau and, often, weight regain once normal eating resumes. A moderate deficit is slower but produces better long-term outcomes for most people.

The Mifflin-St Jeor equation is accurate within about 10% for most people, which in practice means your actual TDEE might be 150 to 200 calories higher or lower than the calculator says. The activity multiplier introduces more uncertainty than the BMR formula itself — people tend to overestimate how active they are. Use the result as a reasonable starting point, track your actual weight change over two to three weeks, and adjust from there. That feedback loop will get you to your true maintenance calories faster than any formula.

Not necessarily, but understanding your approximate calorie needs is genuinely useful even if you don't track every meal. Many people find success with approaches that don't require logging — eating mostly whole foods, reducing portion sizes, cutting out liquid calories, and building in consistent exercise. But if you've tried those approaches and aren't getting results, a few weeks of accurate calorie tracking tends to be illuminating. Most people are surprised by how much they've been underestimating their intake.