How this calorie calculator works
First it estimates your basal metabolic rate (BMR), the energy your body burns at rest, with the Mifflin-St Jeor equation. It is the formula most dietitians use today:
- Men: 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5
- Women: 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161
Then it multiplies your BMR by your activity level to get your total daily energy expenditure (TDEE). That is your maintenance: eat this much and your weight stays about the same.
Calories to lose weight
A deficit of about 500 calories a day leads to roughly 0.5 kg (1 lb) of fat loss per week. A smaller deficit of 250 calories is easier to keep up and protects muscle. We never suggest going below 1,200 kcal for women or 1,500 kcal for men without medical supervision.
Activity multipliers
| Activity level | Multiplier |
|---|---|
| Sedentary | 1.2 |
| Light (1-3 days) | 1.375 |
| Moderate (3-5 days) | 1.55 |
| Active (6-7 days) | 1.725 |
| Very active | 1.9 |
Frequently asked questions
How many calories should I eat to lose weight?
About 500 calories below your maintenance to lose around 0.5 kg (1 lb) per week. Use the "Lose" number above.
How accurate is a calorie calculator?
It is a starting estimate, usually within 10% for most people. Track your meals and weight for 2 to 3 weeks, then adjust by 100 to 200 calories.
How much protein do I need?
Most active people do well with 1.6 to 2.2 g per kg of body weight. Try our protein calculator for a personal number.
What is the easiest way to count calories?
Take a photo of each meal. Pic2Chef uses AI to estimate calories and macros from the picture, so you do not need to weigh or search every food.