Calorie needs
Calculate your TDEE from weight and food
Your TDEE is your total daily energy expenditure, the calories you burn on an average day. Equations estimate it from height, weight, age and activity. Ownit starts with such an equation and then keeps estimating your expenditure from your weight trend and what you eat. Once a week Ownit adjusts your calorie target.
The adaptive TDEE is part of the free version of Ownit.
Updated 7 October 2026
How it works
How Ownit estimates your expenditure
- 01
Start from an equation
Without your own data, Ownit uses the Mifflin-St Jeor equation times an activity factor between 1.2 and 1.9. If you know your maintenance calories, you enter them instead.
- 02
Weigh in and log
You weigh yourself as often as you like and log your food. Ownit spots incomplete days and fills them with an estimate from similar days, weekdays and weekends kept apart.
- 03
Learn your expenditure
A Kalman filter compares your food with your weight trend and corrects the estimate with every weigh-in. After a 14-day learning phase the first adjustment is possible.
- 04
Adjust weekly
On your check day, Sunday by default, Ownit sets the new target. It needs at least one weigh-in and four logged days that week. The new target applies from the next day, or you choose to confirm it yourself.
The rules behind it
What your weekly target sticks to
The aim is a calorie target that follows your estimated expenditure without jumping around from week to week.
- 10 percent at most
- Your target changes by no more than 10 percent per week. If you change your goal or pace yourself, the limit doesn't apply.
- Floor
- Ownit sets no target below 1,200 kcal for women and 1,500 kcal for men.
- Outliers
- The filter drops a weigh-in that is more than 1.5 kg off and far outside the expected noise.
- Settling
- After the start, a goal change or a jump of more than 300 kcal in your intake, the filter takes 10 days before it reacts strongly.
- Cardio
- Ownit calculates cardio from the exercise's MET value, your weight and the duration, and adds 80 percent of it to your target that day.
- Pace
- Ownit plans fat loss at 0.25 to 1 percent of body weight per week, depending on body fat. The starting target stays at 75 percent of your expenditure or more.
- Protein
- 2.2 g of protein per kilo of body weight while dieting, 2.0 g at maintenance and while gaining. Fat and carbs share the rest.
Example
Eight weeks of fat loss with Lena
Lena, 29, starts at 72.6 kg and wants to lose about 0.3 kg a week. The equation puts her expenditure at 2,350 kcal and her first target at 2,000 kcal. She loses faster than planned, so her expenditure was higher.
| Week | Avg eaten | Weight trend | Estimated expenditure | New target |
|---|---|---|---|---|
| 1 | 1,990 kcal | 72.6 kg | 2,350 kcal | 2,000 kcal (learning) |
| 2 | 2,000 kcal | 72.1 kg | 2,410 kcal | 2,000 kcal (learning) |
| 3 | 2,010 kcal | 71.7 kg | 2,480 kcal | 2,130 kcal |
| 4 | 2,120 kcal | 71.4 kg | 2,540 kcal | 2,190 kcal |
| 6 | 2,180 kcal | 70.9 kg | 2,610 kcal | 2,260 kcal |
| 8 | 2,260 kcal | 70.6 kg | 2,640 kcal | 2,290 kcal |
Sample data, rounded. Every adjustment stays under 10 percent.
Backed by science
The research behind these rules
These research fields feed into the feature. Every source is linked with its DOI on the science page.
Resting and total energy expenditure
10 sourcesThe starting value comes from the Mifflin-St Jeor equation times an activity factor.
- Third update of MET values for human physical activitiesHerrmann et al. 2024 · J Sport Health Sci
- Mifflin recommended in obesity; no evidence for total-expenditure equationsMadden, Mulrooney & Shah 2016 · J Hum Nutr Diet
- Mifflin-St Jeor most often landed within 10% of measured RMRFrankenfield, Roth-Yousey & Compher 2005 · J Am Diet Assoc
Energy balance and adaptation
12 sourcesOwnit compares what you eat with what the scale shows over the weeks and keeps re-learning your expenditure from that. If it changes during a diet, your target follows.
- Metabolic adaptation persisted six years after the weight-loss competitionFothergill et al. 2016 · Obesity (Silver Spring)
- Early adaptation was linked to insulin secretion and fluid balanceMüller et al. 2015 · Am J Clin Nutr
- Metabolic adaptation to weight loss: implications for athletesTrexler, Smith-Ryan & Norton 2014 · J Int Soc Sports Nutr
Weight trend and noise
9 sourcesA Kalman filter separates your weight from the daily ups and downs of water and food and drops gross outliers.
- Weekly, seasonal and holiday body weight fluctuation patternsTuricchi et al. 2020 · PLoS One
- Muscle glycogen is stored with at least three times its weight in waterFernández-Elías et al. 2015 · Eur J Appl Physiol
- Weight rises on weekends and falls during weekdaysOrsama et al. 2014 · Obes Facts
Rate of loss and muscle retention
11 sourcesHow fast you lose depends on your body fat, between 0.25 and 1 percent of body weight per week. The starting target stays at 75 percent of your expenditure or more.
- Energy deficit blunted lean-mass gains but not strength gainsMurphy & Koehler 2022 · Scand J Med Sci Sports
- ACSM consensus on weight loss in weight-category sportsBurke et al. 2021 · Curr Sports Med Rep
- Calorie restriction, exercise and rate of loss influence lean mass lostChaston, Dixon & O'Brien 2007 · Int J Obes (Lond)
Limits
What the estimate can't do
- Your expenditure is an estimate from your data. The more completely you log and the more often you weigh in, the more precise it gets.
- Ownit doesn't connect to fitness watches. You log cardio in Ownit.
- Ownit doesn't calculate calorie targets for anyone under 18.
- If you have an eating disorder, are pregnant or have a medical condition, talk to a doctor first.
FAQ
Frequently asked questions
What is TDEE?
TDEE stands for total daily energy expenditure. It is made up of your resting metabolic rate, the energy for digestion, everyday movement and training. If you eat about your TDEE on average, your weight stays stable.
How accurate are TDEE calculators?
In comparison studies the Mifflin-St Jeor equation lands within 10 percent of measured resting metabolic rate for most people, and further off for some. The activity factor adds more uncertainty. That is why Ownit uses the equation only as a starting value.
Why am I not losing weight in a calorie deficit?
Water often hides fat loss for a week or two, for example after salty food, more carbs or a hard workout. Expenditure is also often lower than the equation assumes, or entries are missing. Ownit therefore looks at the trend over weeks and re-estimates your expenditure from your data.
How often should I weigh myself?
One weigh-in a week is enough for the weekly check. The more often you weigh in, the faster the filter separates the trend from the daily ups and downs.
Do I have to log every day?
Four logged days a week are enough for the weekly check. Ownit estimates missing or incomplete days from similar days.
Does cardio count?
Yes. Cardio you log in Ownit raises your calorie target that day. Ownit uses the exercise's MET value and adds 80 percent of the calculated calories.
Is the adaptive TDEE free?
Yes. The expenditure estimate, the weekly adjustment and your calorie target are part of the free version.
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