TDEE Calculator

BMR only reflects the calories your body burns at complete rest, with zero movement or digestion factored in, while TDEE adds in everything else you actually do in a day — walking, exercise, even fidgeting and digesting food — to arrive at your true total energy burn. Eating based on BMR alone would systematically underestimate how much you actually need, since almost nobody spends their entire day lying perfectly still.

It's generally considered more accurate on average than the older Harris-Benedict equation across a wide range of body types and is the formula most commonly recommended by dietitians today, but no equation based only on weight, height, age, and sex can perfectly predict any one individual's actual metabolism. Real BMR varies with muscle mass, genetics, and hormonal factors that these formulas don't directly measure, so it's a solid estimate rather than an exact figure.

A 500-calorie daily deficit or surplus corresponds to roughly a pound of body weight change per week, based on the commonly cited approximation that about 3,500 calories equals one pound of fat — a moderate, sustainable pace that's easier to stick with and less likely to trigger the muscle loss or excessive water retention that more aggressive calorie swings can cause. Faster or slower rates are certainly possible by adjusting the deficit or surplus further, but 500 calories is a well-established, reasonable default.

Recalculating periodically is worthwhile, since TDEE changes as your weight changes — losing weight generally lowers both BMR and TDEE, meaning the same calorie intake that once caused a deficit can eventually become closer to maintenance as you get lighter. Because this is an estimate rather than a direct measurement, tracking your actual weight trend over two to three weeks and adjusting your target calories based on real results is more reliable than trusting a single calculation indefinitely.