Calorie calculations can be confusing at first. Here are the most asked questions answered clearly — so you can use your Horizons Health calculator with confidence.
What is the difference between BMR and TDEE?
BMR (Basal Metabolic Rate) is the calories your body burns at rest (just to stay alive). TDEE (Total Daily Energy Expenditure) is BMR + calories burned from activity. TDEE is what you should eat to maintain weight.
Why does my calorie goal change with activity level?
Higher activity burns more calories, so your body needs more fuel to maintain energy balance. The calculator multiplies BMR by an activity factor (1.2 to 1.9) to give you accurate TDEE.
Is Body Fat % necessary for accurate calories?
Not required — Mifflin-St Jeor works well for most people. But if you enter body fat %, the calculator switches to Katch-McArdle formula (more accurate for lean athletes or people with high muscle mass).
How many calories should I cut/add for weight loss/gain?
A safe deficit is 300–750 kcal/day (0.3–0.75 kg/week loss). Surplus of 300–500 kcal/day is good for muscle gain without too much fat. Extreme cuts (>1000 kcal) can slow metabolism.
Do macros matter if I hit my calorie goal?
Yes — calories control weight, but macros control how you feel and look. Protein preserves muscle, carbs fuel workouts, fats support hormones. Use the suggested split as a starting point.
