How it's calculated
Basal metabolic rate comes from the Mifflin-St Jeor equation, the most accurate of the usual formulas for adults. It is then multiplied by an activity factor to get total daily energy expenditure (TDEE).
The goal applies −20 % for a cut (about 0.5 to 0.75 % of bodyweight lost per week) and +10 % for a gain, enough to progress without putting on too much fat.
Macros built for strength
Protein is set at 2 g per kilo of bodyweight, 2.2 g on a cut to keep muscle. Fat is 0.9 g per kilo, never under 20 % of calories. Carbs fill the rest: they fuel heavy sessions.
These numbers are a starting point. Weigh yourself several times a week and adjust by 100 to 200 kcal if the two-week trend goes the wrong way.
Frequently asked questions
Which activity level should I pick?
Count your sessions and daily activity. 3 to 4 strength sessions a week with a desk job is usually "moderate". When in doubt, pick the lower level.
Should calories change on rest days?
Not necessary. A steady weekly average works for most athletes.
Can I use this to make weight for a meet?
It helps for gradual weight loss over several weeks. A fast cut before a weigh-in (water manipulation) is a different process, best done with a coach.
How many calories do I need to build muscle?
About 10 % above maintenance, with 2 g of protein per kilo. Aim to gain 0.25 to 0.5 % of bodyweight per week to limit fat gain.
How much protein per day for lifting?
1.6 to 2.2 g per kilo of bodyweight (0.7 to 1 g per pound). The calculator uses 2 g, 2.2 g on a cut to protect muscle.
How do I find my maintenance calories?
Basal metabolic rate (Mifflin-St Jeor) times your activity level. Then check over two weeks: if your weight is stable, you're at maintenance.