FitCalculation- Activity multiplier
The factor applied to your BMR to estimate TDEE, from 1.2 for sedentary up to 1.9 for very hard training or a physically demanding job. It describes your average week, not your hardest day.
Used inTDEE CalculatorCalorie CalculatorCalorie Deficit CalculatorBulking Calculator
- BMI — Body Mass Index
A screening ratio of weight to height, calculated as weight in kilograms divided by height in metres squared, and placed against standard adult categories. BMI is a population screening measure, not a diagnosis: it cannot tell muscle from fat, so a muscular person can score high while carrying very little body fat.
Used inBMI CalculatorBody Fat CalculatorLean Body Mass Calculator
- BMR — Basal Metabolic Rate
The calories your body burns at complete rest, measured while awake but totally inactive. TDEE is built on top of BMR by multiplying it by an activity factor.
- Body fat percentage
The share of your total body weight that is fat, as a percentage. This site estimates it from tape measurements using the U.S. Navy circumference equation, which needs no scale and is useful for tracking change over time — but it is an estimate, and clinical methods such as DEXA measure fat directly.
Used inBody Fat CalculatorLean Body Mass CalculatorBody Recomposition Calculator
- Body recomposition
Losing fat while keeping or adding lean mass, usually at a modest deficit with higher protein and progressive resistance training. It is slower than a straight cut, and the fat loss cannot be predicted from a calorie formula alone — so this site returns a calorie and protein target rather than a promised result.
Used inBody Recomposition CalculatorProtein CalculatorCalorie Deficit Calculator
- Bulking
A deliberate phase of eating at a surplus to gain weight, usually aiming to add muscle with as little extra fat as possible. Bulking also raises the protein target, since muscle is built from protein over time rather than stored directly.
Used inBulking CalculatorCalorie Surplus CalculatorProtein Calculator
- Calorie deficit
Eating fewer calories than you burn, which is what makes body fat decline. This site plans a deficit from a target rate of loss — using roughly 7,700 kcal as the energy equivalent of 1 kg of body fat — and caps the result at a safe minimum rather than recommending extreme intake.
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- Calorie surplus
Eating more calories than you burn, so the surplus can be stored as new tissue. Surpluses are planned from a target rate of gain and capped at a maximum daily target on this site.
- Lean body mass
Everything that is not body fat: bone, muscle, organ, and skin mass, expressed in kilograms or pounds. Once you know your body fat percentage, lean mass is your body weight multiplied by one minus that percentage.
Used inLean Body Mass CalculatorBody Fat CalculatorBody Recomposition Calculator
- Macros — Macronutrients
Protein, carbohydrate, and fat — the three nutrients that supply nearly all dietary energy. A macro split divides a calorie target into grams of each: 4 kcal per gram of protein and carbohydrate, 9 kcal per gram of fat.
- Maintenance calories
The daily intake that would hold your weight roughly steady — your TDEE. It is a moving estimate: it shifts as you get lighter, as your activity changes, and as your body adapts, so a real maintenance number is found by watching your weight trend over several weeks.
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- Mifflin-St Jeor equation
The equation this site uses to estimate BMR from age, sex, height, and weight. It was published in 1990 and replaced the earlier Harris-Benedict formula, which overestimated resting burn in most people.
Used inTDEE CalculatorCalorie CalculatorCalorie Deficit CalculatorCalorie Surplus Calculator
- Protein
The macronutrient that supports muscle repair and maintenance, worth 4 kcal per gram. This site sets a daily target from your body weight in kilograms — a range that rises on cutting and bulking goals, and falls back to a general range for maintenance.
Used inProtein CalculatorMacro CalculatorBulking CalculatorBody Recomposition Calculator
- TDEE — Total Daily Energy Expenditure
The total number of calories your body uses in an average day: your resting burn plus the energy spent moving, exercising, and digesting food. Eating around your TDEE is what holds your weight steady.
Used inTDEE CalculatorCalorie CalculatorBody Recomposition Calculator