What is the Calorie Calculator?
A calorie calculator works out the daily calories you should eat to lose, maintain or gain weight, plus a protein-fat-carb macro split based on your weight and goal.
We start from BMR (Mifflin–St Jeor), multiply by your activity factor to get TDEE, then add or subtract 500 kcal for a roughly 0.5 kg/week change.
Formula
Target = BMR × Activity − 500 (lose) / +0 (maintain) / +500 (gain)
- Activity factor — 1.2 sedentary · 1.375 light · 1.55 moderate · 1.725 active · 1.9 very active
- Protein target — 1.6 g/kg body weight (research-backed for active adults)
- Fat target — ~25% of total calories from fat (9 kcal/g)
Step-by-step example
Setup: Male, 28 yrs, 70 kg, 172 cm, moderately active, maintain.
- BMR ≈ 1,640
- TDEE = 1,640 × 1.55 ≈ 2,542
- Protein ≈ 112 g · Fat ≈ 71 g · Carbs ≈ 270 g
Answer: Target ≈ 2,542 kcal · 112 P / 71 F / 270 C
Frequently asked questions
Is 500 kcal deficit safe?
For most healthy adults, yes — it averages around 0.5 kg/week of fat loss. Larger deficits risk muscle loss and metabolic slowdown.
Do I need to track macros?
Not forever. Tracking for 2–4 weeks calibrates portion sizes; after that most people can eat intuitively while hitting targets.