Free tool
Calorie calculator
Find out about how many calories your body uses each day, and what to aim for if you want to lose, keep, or gain weight.
How this calculator works
First, it estimates your resting burn (BMR). That's the energy your body uses just to keep you alive: breathing, pumping blood, and staying warm. We use the Mifflin-St Jeor equation, which is the formula the Academy of Nutrition and Dietetics recommends for many adults.
Then it multiplies your resting burn by your activity level. That gives your total daily burn, or the calories you'd eat to keep your weight the same.
How fast should I lose weight?
Slow and steady works best. The CDC says people who lose about 1 to 2 pounds a week are more likely to keep it off. Eating about 250 to 500 fewer calories a day is a common way to get there.
You don't have to count every calorie. Small swaps add up. Water instead of one soda saves about 150 calories. A 30-minute walk burns about 100 to 150.
Common questions
What's the difference between BMR and total daily burn?
BMR is what you'd burn resting all day. Total daily burn adds everything else: walking, working, chores, and exercise. You should eat based on total daily burn, not BMR.
Why does the calculator warn me about low numbers?
Eating very little makes it hard to get enough protein, vitamins, and minerals, and it's hard to keep up. Very low-calorie diets should only be done with a doctor's help.
Why am I not losing weight at this number?
Formulas are estimates and can be off by a few hundred calories. It's also easy to underestimate what we eat. Track your weight for 2 to 3 weeks, then adjust by 100 to 200 calories if needed.
Does this work if I take a GLP-1 medicine?
The math is the same, but your appetite may be much lower. Focus on getting enough protein and fluids, and follow your care team's advice.
A note on safetyThis tool gives general estimates for healthy adults. It isn't medical advice. If you're pregnant, under 18, have a health condition, or take medicine that affects your weight or fluids, ask your doctor what's right for you.
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