Basal rate, daily need, deficit — what the numbers mean
Your basal metabolic rate (BMR) is what your body burns at complete rest — just breathing, your heartbeat, your organs. We calculate it with the Mifflin-St Jeor equation, today's best-validated formula for resting metabolic rate.
Your daily need (TDEE, Total Daily Energy Expenditure) is your basal rate times an activity factor. We use 1.55 — a desk job plus two strength sessions and one easy cardio session per week. Exactly the Dad Strong rhythm.
The deficit is how much you eat below your daily need. No deficit, no fat loss — it's that simple. But it can't be too big either, or you lose muscle instead of fat.
How many calories to lose weight as a man?
The honest answer: it depends on your daily need — that's what the calculator is for. For most men with a desk job and two strength sessions, the need sits between 2,400 and 2,900 kcal. To lose fat, subtract 200 to 600 kcal.
A moderate deficit of 300–500 kcal per day is the best compromise for most: visible results without constant hunger or crashing in your workouts. More isn't better — it's just faster and riskier.
Lose fat and keep muscle — at the same time
The reason this calculator recommends a moderate deficit instead of a crash diet: strength training plus enough protein plus a small deficit is the combination that lets you lose fat and still stay strong — or even build muscle if you were untrained before.
That's why the calculator is tuned to Dad Strong training: two fixed strength workouts per week are the engine, the deficit is the direction. Without the training, a deficit would just make you smaller — not stronger.