What your body uses in a day, and what intake a given rate of loss needs — with the equations shown, because every calculator that hides them is hiding the same two.
Sex at birth
Age
Weight
Height
Body fat % — optional
Enter one and it switches to Katch–McArdle, which works from lean mass and ignores sex. A scale’s reading is an estimate; a DXA figure is a measurement.
Activity
Total daily energy expenditure
—kcal/day
Resting (BMR)
—
Protein target
—
1.2–1.6 g per kg body weight
The link carries everything you entered, so what you send is the calculator set as you left it.
These are estimates, and the error bar is wide. Measured resting expenditure varies by roughly ±10% around what these equations predict, and the activity factors are convention, not a measurement of you. Test the output against the scales over a few weeks.
Protein is the one that matters on a GLP-1. Appetite falls faster than requirement, and lean mass is what goes when protein does not keep up. Resistance training alongside it is what the trials consistently show protects lean tissue.
Amber rows fall below the intakes usually considered a floor without supervision (about 1500 kcal for men, 1200 for women). That is a conversation with your prescriber or a dietitian, not a target to set yourself.
Mifflin–St Jeor (1990) — the default, because it only needs what everyone knows about themselves:
men: BMR = 10 × kg + 6.25 × cm − 5 × age + 5
women: BMR = 10 × kg + 6.25 × cm − 5 × age − 161
Katch–McArdle — used instead as soon as a body-fat percentage is entered, because once lean mass is known it is the better estimate and it does not need sex at all:
BMR = 370 + 21.6 × lean kg
TDEE is BMR × the activity factor shown beside each option (1.200 to 1.900, the conventional Harris–Benedict set).
The loss table uses 7700 kcal per kg of fat, so 0.5 kg a week is
0.5 × 7700 ÷ 7 = 550 kcal a day. That assumes the weight lost is
fat; early weeks lose water too, which is why the scales move faster than the arithmetic at
the start and slower later.
GLP Master is an information and record-keeping project. Nothing here is medical advice, or a recommendation to start, stop or change any treatment or diet.
If you are on a medicine that affects appetite, decisions about intake belong with you and your own prescriber.