TDEE calculator
Estimate how many calories you use in a day from your age, height, weight, and activity. It’s a starting point for setting a goal, not a measurement or a personal prescription.
Within ±10%: 1,660–2,030
At least one reference point is below your estimated resting energy. Plan an intake that low with a clinician.
Rounded to the nearest 10 calories. Reference points are arithmetic, not targets.
How this calculator works
First it estimates your basal metabolic rate (BMR) with the Mifflin-St Jeor equation, published in 1990 from resting energy measurements in 498 healthy adults:
Men: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5
Then it multiplies BMR by an activity factor to estimate total daily energy expenditure:
US units are converted first: 1 lb = 0.4536 kg and 1 inch = 2.54 cm.
Activity factors
| Activity level | A typical week | Factor |
|---|---|---|
| Sedentary | Mostly sitting, with little or no exercise | × 1.2 |
| Lightly active | Light exercise or sports 1–3 days a week | × 1.375 |
| Moderately active | Moderate exercise or sports 3–5 days a week | × 1.55 |
| Very active | Hard exercise or sports 6–7 days a week | × 1.725 |
| Extra active | Very hard daily training or a physically demanding job | × 1.9 |
These multipliers are widely used conventions, not measurements. They are one of the biggest sources of uncertainty in any TDEE estimate.
A worked example
The starting example is a 35-year-old woman who is 165 cm tall, weighs 65 kg, and is lightly active.
TDEE = 1,345.3 × 1.375 = 1,849.7, or about 1,850 calories a day
How accurate is it?
A 2005 systematic review of the most common equations found Mifflin-St Jeor the most reliable: it estimated resting metabolic rate within 10% of the measured value in more people than the other equations did. The same review warned about noteworthy errors for some individuals, and noted that older adults and US ethnic minorities were underrepresented in the research. That’s why the result shows a ±10% range alongside the estimate.
From estimate to starting point
The most useful check is your own record. Log what you eat for two to three weeks, weigh yourself under similar conditions, and compare your average intake with your weight trend. Day-to-day weight moves with water, salt, and food in transit, so the trend matters more than any single day.
Weight change also isn’t linear. Research behind the NIH Body Weight Planner shows that the body adapts to a change in intake and weight responds slowly, so a fixed daily difference doesn’t produce the same weekly change forever. The Body Weight Planner models that for a goal and a timeline.
If you use Calorify, enter your number as the daily calorie target on the Goals screen, then review it once you have a few weeks of entries.
If you have a medical condition, are pregnant or breastfeeding, or have a history of disordered eating, talk with a registered dietitian or doctor before you set a calorie target.
Frequently asked questions
What is TDEE?
Total daily energy expenditure (TDEE) is an estimate of the calories you use in a day: your resting energy plus everything you do on top of it, from walking and working to exercise and digesting food. Eating about your TDEE is often called maintenance.
What is the difference between BMR and TDEE?
BMR, or basal metabolic rate, estimates the energy your body uses at rest. This calculator estimates it with the Mifflin-St Jeor equation, which was built from measured resting energy expenditure. TDEE multiplies that resting estimate by an activity factor.
Which activity level should I choose?
Pick the description that matches a typical week, not your most active one. If you’re between two levels, start with the lower one and adjust after a few weeks of logging.
Why does my fitness tracker show a different number?
Trackers and equations estimate energy use in different ways, and both can be off. Neither is a measurement. Pick one estimate, log your intake consistently, and compare it with your weight trend over several weeks.
Who should not rely on this calculator?
It is designed for adults. The equation was developed in adults aged 19 to 78, so it may fit children, teenagers, older adults, athletes, and people with some medical conditions less well. It does not account for pregnancy or breastfeeding. A registered dietitian or doctor can give you a personal estimate.
Sources
- Mifflin MD, St Jeor ST, et al. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990;51(2):241–247 ↗
- Frankenfield D, et al. Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: a systematic review. J Am Diet Assoc. 2005;105(5):775–789 ↗
- Hall KD, et al. Quantification of the effect of energy imbalance on bodyweight. Lancet. 2011;378(9793):826–837 ↗
- NIDDK Body Weight Planner ↗
General education, not individualized medical or nutrition advice. See also the macro calculator and our guide to macro ratios.
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