Resting energy
What your body burns doing nothing, from the Mifflin–St Jeor equation: 10 × weight (kg) + 6.25 × height (cm) − 5 × age, then +5 for men or −161 for women.
TDEE
calculator.
Find your TDEE, the calories you burn in a day, from your age, height, weight and activity, and see roughly how much to eat to lose weight at a steady pace.
Your numbers
ExampleWhat is TDEE?
TDEE, or total daily energy expenditure, is how many calories you burn in a day. Most of it is the energy your body uses just to keep running, your resting energy. The rest is activity: walking, working, exercising, even fidgeting. Eat about your TDEE and your weight stays roughly where it is; eat less and you lose weight.
How do I calculate my TDEE?
In two steps: estimate your resting energy, then multiply it by your activity level. For a 30-year-old woman who is 165 cm (5′5″) and 68 kg (150 lb):
Resting energy = 10 × 68 + 6.25 × 165 − 5 × 30 − 161 ≈ 1,400 kcal a day
| Activity level | Multiplier | TDEE |
|---|---|---|
| Mostly sittingDesk job, little exercise | × 1.2 | 1,680 kcal |
| Lightly activeOn your feet some of the day, or 1–3 workouts a week | × 1.375 | 1,930 kcal |
| Active3–5 workouts a week | × 1.55 | 2,170 kcal |
| Very activeHard exercise most days, or a physical job | × 1.725 | 2,420 kcal |
The calculator above does the same for your numbers, and shows how much of your TDEE is resting energy and how much is activity.
How does the Mifflin–St Jeor TDEE calculator work?
It uses the Mifflin–St Jeor equation (1990) for resting energy, with weight in kilograms, height in centimetres and age in years:
Women: 10 × weight + 6.25 × height − 5 × age − 161
Men: 10 × weight + 6.25 × height − 5 × age + 5
Then it multiplies by your activity level: 1.2 if you mostly sit, 1.375 if you’re lightly active, 1.55 if you work out 3–5 times a week, and 1.725 if you do hard exercise most days or have a physical job. We round the result to the nearest 10 kcal, because the estimate isn’t precise enough to deserve more digits.
How accurate is a TDEE calculator?
Close enough to start, not close enough to trust blindly. A systematic review found Mifflin–St Jeor was more likely than the other common formulas to land within 10% of a measured resting rate, but it still found noteworthy errors for individuals, especially older adults and groups the studies underrepresented. Picking an activity level adds a second guess on top.
That’s why our app Forward treats the formula as a first estimate. After two or three weeks, your 7-day weight average shows whether you’re really losing at the pace you planned, and you adjust from there.
No magic
How the
numbers work.
Activity level
Resting energy times a multiplier for how active you are: 1.2 if you mostly sit, up to 1.725 if you do hard exercise most days.
For weight loss
About 7,700 kcal ≈ 1 kg of body weight, so losing 0.25–0.75 kg (0.5–1.5 lb) a week means eating about 280–830 kcal a day less than your TDEE.
Safety floors
We don’t suggest eating under 1,200 kcal a day (women) or 1,500 (men). If every pace would go under that, the gentle one eats at the floor with a smaller deficit; if you burn no more than that, we don’t suggest a deficit at all.
Sources: Mifflin et al., American Journal of Clinical Nutrition (1990) · Frankenfield et al., Journal of the American Dietetic Association (2005)
Questions,
answered.
What is TDEE?
TDEE stands for total daily energy expenditure: the calories you burn in a day, counting the energy your body uses at rest plus everything you do on top. Eat about that much and your weight stays roughly the same.
What’s the difference between BMR and TDEE?
BMR, or resting energy, is what your body burns doing nothing. TDEE adds your activity on top. This calculator estimates resting energy with the Mifflin–St Jeor equation, then multiplies it by your activity level.
How many calories should I eat to lose weight?
About 280 to 830 kcal a day less than your TDEE, for 0.25 to 0.75 kg (0.5 to 1.5 lb) a week. For a 30-year-old woman who is 165 cm and 68 kg and lightly active, that’s roughly 1,380 to 1,650 kcal a day; our fastest pace would take her under 1,200 kcal, so we wouldn’t suggest it. We don’t suggest going under 1,200 kcal a day for women or 1,500 for men.
Which activity level should I pick?
If you’re not sure, pick the lower one. Most people overestimate how active they are, and a desk job with a few workouts a week usually fits “Lightly active” better than “Active”.
Why is my TDEE different on other calculators?
Calculators use different formulas and activity multipliers, and all of them are estimates. Pick one, eat to it for two or three weeks, and adjust based on what your weight actually does.
Is this medical advice?
No. It’s a general estimate for healthy adults. If you’re under 18, pregnant or breastfeeding, have a medical condition, or have a history of disordered eating, talk to a doctor before changing how you eat.
Forward does this
every day.
Forward swaps the activity guess for your real steps and workouts from Apple Health, and turns it into one number: what’s left to eat today. It’s coming to iPhone.