How your calories are worked out
First your BMR, the energy you burn at rest. The default Mifflin-St Jeor equation is:
women: 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161
Your maintenance calories (TDEE) are BMR times an activity factor from 1.2 (sedentary) to 1.9 (very active). About 3,500 kcal is a pound of fat, so eating 500 kcal under maintenance loses roughly 1 lb a week.
Cut, maintain or bulk?
With your body fat %, men over 25% or women over 32% are pointed to a cut, and men under 12% or women under 20% to a lean bulk. Without it, BMI is used: under 22 lean bulk, 22 to 25 maintain, 25 and over cut. Macros follow the plan: protein 2.2 g per kg on a cut and 1.8 otherwise, fat 25% of calories, carbs the rest.
This is general guidance, not medical advice. Eating under 1,500 kcal (men) or 1,200 kcal (women) a day isn't recommended without a doctor.
Questions
How many calories should I eat to lose weight?
Eat about 500 kcal a day under your maintenance calories to lose about 1 lb (0.5 kg) a week. The table shows mild, normal and fast options.
What are maintenance calories?
The calories you burn in a day, also called TDEE. It's your BMR (calories at rest) times how active you are. Eating this much keeps your weight steady.
Should I cut or bulk?
If your body fat or BMI is high, cut first. If you're lean, a slow lean bulk adds muscle with little fat. In between, eating at maintenance while you train (a recomp) works well.
Which formula is most accurate?
Mifflin-St Jeor is accurate for most people. If you know your body fat percentage, Katch-McArdle accounts for muscle and is often closer.