What formula does this use?

Mifflin-St Jeor for resting metabolic rate, which performs best in validation studies on adults, multiplied by a standard activity factor from 1.2 for sedentary to 1.9 for extremely active.

What's the difference between BMR and TDEE?

BMR is what you'd burn lying still all day. TDEE adds everyday movement and exercise. You eat against TDEE, not BMR.

Within about 10 to 15 percent for most adults. It's a starting point. If your weight doesn't move after three weeks at the calories it suggests, adjust by 100 to 200 a day.

Does metabolism really slow after 40?

Less than most people think. Large studies show resting metabolism holds steady until about 60. What changes earlier is muscle mass, activity, sleep and hormones, which all shift how much you eat and move.

Free tools

TDEE calculator

Total daily energy expenditure is the number of calories you burn in a typical day: what your body uses at rest, plus activity. It's the starting line for any weight goal, because a deficit or a surplus only means something against this number.

Sex

Age

years

Height

Weight

Activity

Calories you burn a day

1,948kcal

At rest (BMR)

1,417 kcal

To lose 1 lb a week

1,448 kcal

To gain 0.5 lb a week

2,198 kcal

Mifflin-St Jeor formula times the activity multiplier you picked. Real-world burn varies by 10 to 15 percent either way, so treat this as a starting point and adjust after two or three weeks on the scale. Turn it into a plan.

Eating under this number and still stuck?

Appetite, sleep and hormones all change what the number does in practice. If a deficit hasn't worked, a doctor can look at why.

See GLP-1 weight loss

Free doctor review, usually within 24 hours. You're not charged unless they write the prescription.

Common questions

What formula does this use?: Mifflin-St Jeor for resting metabolic rate, which performs best in validation studies on adults, multiplied by a standard activity factor from 1.2 for sedentary to 1.9 for extremely active.
What's the difference between BMR and TDEE?: BMR is what you'd burn lying still all day. TDEE adds everyday movement and exercise. You eat against TDEE, not BMR.
How accurate is it?: Within about 10 to 15 percent for most adults. It's a starting point. If your weight doesn't move after three weeks at the calories it suggests, adjust by 100 to 200 a day.
Does metabolism really slow after 40?: Less than most people think. Large studies show resting metabolism holds steady until about 60. What changes earlier is muscle mass, activity, sleep and hormones, which all shift how much you eat and move.

More tools

BMI calculatorYour body mass index and the healthy weight range for your height Calorie deficit calculatorDaily calories for a weight goal, and how long it takes Protein calculatorGrams of protein a day for your weight and goal Water intake calculatorHow much to drink a day for your weight, exercise and climate

These calculators give estimates from standard formulas for healthy adults. They are not medical advice and don't account for pregnancy, medical conditions or medications. Decisions about treatment are made by the licensed providers in our network.