How this calorie calculator works
First it estimates your basal metabolic rate (BMR), the energy your body uses at complete rest, with the Mifflin–St Jeor equation:
| Men | 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5 |
| Women | 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161 |
It then multiplies BMR by an activity factor to estimate your total daily energy expenditure (TDEE), the calories you would eat to keep your weight roughly stable:
| Activity level | Typical week | Factor |
|---|---|---|
| Sedentary | Little or no exercise | × 1.2 |
| Lightly active | Exercise 1–3 days a week | × 1.375 |
| Moderately active | Exercise 3–5 days a week | × 1.55 |
| Very active | Hard exercise 6–7 days a week | × 1.725 |
| Extra active | Physical job plus training | × 1.9 |
Choosing a calorie target
To maintain your weight, start near your TDEE. To lose weight, eat a little less: a deficit of 250 to 500 kcal a day is a common, moderate starting point. To gain weight, eat a little more. As a rough rule of thumb, a 500 kcal daily deficit adds up to around 0.5 kg (about 1 lb) a week, though real-world change varies.
Our guide to the calorie deficit explains how to choose and follow a target, and the macro calculator turns it into grams of protein, carbs and fat.
Why your result is an estimate
Equations describe averages across many people. Muscle mass, health conditions, medication and how active you really are can all move your needs up or down. The most reliable way to refine the number is to log your food consistently for a few weeks and compare it with your weight trend.
Track against your target with CutWise
In the CutWise app, a Programme estimates a daily calorie target from your profile, activity level and goal. Log meals by photo, voice, text or barcode, review each estimate, and follow your weight trend alongside your intake.
