Calorie & BMR Calculator
Find your basal metabolic rate (BMR), the calories you burn at rest, and how many calories you need each day to maintain, lose or gain weight.
How to calculate your daily calories
- Choose metric or imperial units and your sex, then enter your age, height and weight.
- Pick the activity level that best matches a typical week.
- Read your BMR, your maintenance calories and the daily calorie targets for losing or gaining weight.
Features
Mifflin-St Jeor equation
A widely used and well-tested BMR formula.
Goals for loss and gain
Daily calories and expected weekly change for six goals.
Metric and imperial
Switch units and your numbers are converted for you.
Private
Everything runs in your browser; nothing is sent anywhere.
Understanding BMR and daily calorie needs
Your basal metabolic rate (BMR) is the energy your body uses just to stay alive at complete rest: breathing, circulation, temperature control and cell repair. It usually makes up 60 to 70 percent of the calories you burn in a day. This calculator estimates it with the Mifflin-St Jeor equation, which research has found to be one of the most accurate for most adults: 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5 for men or − 161 for women.
To estimate your total daily energy expenditure (TDEE), the BMR is multiplied by an activity factor from 1.2 for a desk job with no exercise up to 1.9 for very hard daily training. Eating about this many calories should keep your weight steady. A deficit of around 500 calories a day, which is roughly 0.45 kg or 1 lb of weight loss per week, is a common and sustainable target; a surplus of 250 to 500 calories supports gradual weight gain.
Use the result as a starting point, not a rule. Real needs vary with muscle mass, genetics, sleep, stress and health conditions, so watch your weight over two to three weeks and adjust. If you are pregnant, under 18, or have a medical condition, speak with a doctor or dietitian first.
Frequently asked questions
What is BMR?
BMR is basal metabolic rate: the number of calories your body burns at complete rest in 24 hours. It does not include walking, exercise or digesting food.
Which formula does this calculator use?
The Mifflin-St Jeor equation: BMR = 10 × kg + 6.25 × cm − 5 × age + 5 (men) or − 161 (women). Total daily calories are BMR × an activity factor.
How many calories should I eat to lose weight?
Eating about 500 calories below your maintenance level usually leads to losing about 0.45 kg (1 lb) a week. Avoid going below 1,200 kcal (women) or 1,500 kcal (men) without medical advice.
How accurate is it?
It is an estimate, typically within 10 percent for healthy adults. Muscle mass, age, medication and health conditions change your real needs, so adjust after tracking your weight for a few weeks.
Is my information stored?
No. All calculations happen in your browser and nothing is sent or saved.