TDEE / Fat Loss / Diet Calculator Full Calculator
Adjust your profile, goal, diet and calculation inputs on one page.
Select this if you follow a reduced-carbohydrate diet for personal wellbeing or on professional advice. Each diet decides whether and how to use this preference. About reduced carbohydrates (opens in a new tab)
How this calculator estimates your calorie needs
Your starting point is basal metabolic rate (BMR): an estimate of the energy your body uses at rest. The default Mifflin-St Jeor formula uses your age, sex, height, and weight. You can choose another supported formula in Settings. Each formula is an estimate based on population data, so its result may differ from your own measured energy use.
The calculator multiplies BMR by your activity level to estimate total daily energy expenditure (TDEE). Your usual movement, work, and exercise affect this estimate. The steps setting can add walking above the amount already expected at your selected activity level. If you log a separate exercise session, the calculator accounts for the resting energy you would have used during that time to avoid counting it twice.
Your goal changes the calorie target. A weight loss goal calls for a deficit; maintenance aims near estimated TDEE; weight gain calls for a surplus. The due date and target weight affect the pace shown in the projection. Calorie floors and other limits can prevent the requested pace from being used exactly. The projected weight line shows a possible path, with a range to make the uncertainty visible.
The macro plan divides the daily calorie target among protein, fat, and carbohydrate. Diet presets change that split, while protein and fat minimums limit how far it can shift. Some combinations cannot satisfy every target; the calculator shows a warning when that happens. Compare the plan with your actual weight trend over several weeks and adjust it as needed. Medical conditions, medication, pregnancy, and a history of disordered eating can change what is appropriate for you; ask a qualified professional before using an aggressive diet.
Read the full methodology and review the research references.