Calorie calculator (TDEE)
Estimate your daily calorie target — to maintain, lose or gain weight — with the NASEM 2023 equations and a weekly pace sized to your body. A free, evidence-based starting point, not medical advice.
Target = expenditure (NASEM 2023) ± a step for your pace
Your details
years
kg
cm
Calculating…
Results are for reference only and are not medical advice. For individual guidance, consult a doctor or dietitian.
Next step
Turn the number into a result
This calculation is a guide. In the RESET app it becomes a personal plan that counts calories and macros for you, and opens the transformation programs.
How this calculator works
Briefly and honestly: the science behind it, how far you can trust it, and its limits.
How it works
First the calculator estimates how much energy you spend in a day — with the NASEM 2023 equations, which take sex, age, height, weight and activity level into account. To lose or gain, a step for the pace you pick is taken off (or added to) that expenditure: the pace is a share of your body weight per week, and the energy in each kilogram is costed for your body composition. Resting energy is shown separately, from the Mifflin–St Jeor equation. The calculation is the same one the RESET app runs.
Target = expenditure (NASEM 2023) ± a step for your pace
What it’s based on
Expenditure comes from the NASEM 2023 equations (Dietary Reference Intakes for Energy). They were derived from doubly labelled water measurements — the most accurate way to learn how much energy a person really spends in a day — rather than from a resting rate times a multiplier. Resting energy uses Mifflin–St Jeor (1990); in the app, if you give a body-fat estimate, it uses Katch–McArdle, from fat-free mass. How much energy a kilogram of weight change holds depends on body composition: the more fat tissue, the bigger the share of each kilogram that is fat (the Forbes relation, the Chow and Hall model, 2008). The pace is a share of body weight per week: 0.5–1% (Helms et al., 2014), and 30% gentler below a BMI of 25. Fibre: at least 25 g a day (EFSA).
✓
Is it validated?
The NASEM 2023 equations are built on a large database of doubly labelled water measurements and are recommended for adults across every BMI category. In comparison studies Mifflin–St Jeor is among the most accurate resting-energy equations for healthy adults. The pace limits: to lose, no more than 1 kg a week (NICE) and a deficit no larger than 1,000 kcal a day (NHLBI, 1998); to gain, no more than 0.5 kg a week and 500 kcal above expenditure. The 0.5 kg and the 500 kcal are our own cautious conventions, as are the BMI-25 edge and the 30% slower pace: there is no primary source for those exact numbers, and the reason behind the last two is the Forbes relation.
Can you rely on it?
It is a sound estimate, not a measurement: real expenditure depends on genetics, body composition and daily movement. The most reliable approach is to start from this number and check it against your weight trend over 2–3 weeks. The calculator shows a weekly pace, not a date: the road to a goal is the app’s job, where the plan updates with every weigh-in. The target never goes below a safe calorie minimum; if the chosen pace goes past safe limits, we ease it and say so on screen. The equations were derived in adults and are not meant for pregnancy, breastfeeding or clinical conditions.
Results are for reference only and are not medical advice. For individual guidance, consult a doctor or dietitian.
For the curious
Deeper: why it works this way, what it does for your body, and what happens if you get it wrong.
Most of the body’s energy goes simply to staying alive — breathing, the heart and brain, body temperature. The rest goes to movement: training, and everything else you do in a day. The NASEM 2023 equations estimate all of it together, because they were derived from measurements of real daily expenditure rather than assembled from factors.
A kilogram of weight is not always the same amount of energy. In a body with more fat to spare, a bigger share of each kilogram lost is fat; in a leaner one, more of it is muscle and water. So the calculator sets the pace as a share of body weight per week and costs each kilogram for your body, instead of using the “7,700 kcal per kilogram” rule.
Too sharp a deficit raises hunger and fatigue, takes muscle with it and often stalls progress. The sustainable way is a moderate pace, adjusted to your actual weight trend. That is why the calculator caps the pace and never takes the target below a safe minimum.
Worked examples
Concrete numbers for common situations — so you can see at a glance how to read the result.
Woman, 30, 65 kg, 165 cm
- Inputs
- moderate activity · maintain weight
- Result
- ≈ 2,312 kcal/day
This is the whole day’s expenditure; ≈ 1,370 kcal of it the body uses even at rest.
Man, 35, 90 kg, 180 cm
- Inputs
- sedentary · lose weight, steady pace
- Result
- ≈ 2,134 kcal/day · ≈ 0.67 kg a week
Expenditure is ≈ 2,813 kcal; the pace is about 0.75% of body weight a week, inside the 0.5–1% band.
Woman, 28, 58 kg, 168 cm
- Inputs
- light activity · lose weight, steady pace
- Result
- ≈ 1,918 kcal/day · ≈ 0.3 kg a week
The BMI here is under 25, so the pace is 30% gentler: with less fat to spare, a fast loss takes more muscle with it.
FAQ
Frequently asked questions
How many calories do I need a day?
It depends on sex, age, height, weight and activity level, so there is no universal number. The calculator estimates your own daily expenditure with the NASEM 2023 equations; a few typical cases are in the worked examples.
What is the difference between resting energy and TDEE?
Resting energy is what the body uses at complete rest: breathing, heart, brain. TDEE is the whole day’s expenditure, movement and training included. The calculator shows both: TDEE from the NASEM 2023 equations, resting energy from Mifflin–St Jeor.
What pace of weight loss is safe?
The usual advice is 0.5–1% of body weight a week and no more than 1 kg. The calculator keeps the pace inside those limits, makes it gentler below a BMI of 25, and never takes the target below a safe calorie minimum. This is general information, not medical advice.
Why doesn’t the calculator say when I’ll reach my goal?
Because the honest answer depends on how your body changes: expenditure shifts with every kilogram. The calculator shows the weekly pace; the road to a goal is the app’s job, where the plan updates after every weigh-in.
Which activity level should I choose?
The levels are defined by steps a day (the Tudor-Locke classification): under 5,000 is sedentary, 5,000–7,500 light, 7,500–10,000 moderate, 10,000–12,500 high, over 12,500 very high. Training counts too. If unsure, pick the lower level and check the target against your weight trend over 2–3 weeks.
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