Introduction
Total Daily Energy Expenditure, usually shortened to TDEE, is an estimate of how many calories your body uses over the course of a normal day. People often reach for this number when they want to answer a very practical question: How much should I eat if I want my body weight to stay about the same, go down slowly, or go up slowly? A TDEE estimate is useful because it turns abstract ideas about metabolism and activity into a number you can actually test in daily life. It is not a promise, and it is not a diagnosis. Instead, it is a starting point that becomes more valuable when you compare it with what happens to your body weight and training performance over a few weeks.
Behind the scenes, TDEE is built from two broad pieces. The first is your Basal Metabolic Rate, or BMR, which is the energy your body would use even if you rested all day. That covers the work your body does just to keep you alive: breathing, circulation, temperature regulation, organ function, and the constant cellular work that never fully stops. The second piece is everything you do on top of rest: formal exercise, walking, standing, household tasks, work activity, fidgeting, and even some of the energy needed to digest food. Because the second piece changes a lot from person to person, the biggest challenge in TDEE estimation is often not the BMR formula itself but choosing an activity level that matches your real week instead of your most ambitious day.
This calculator uses the widely used Mifflin-St Jeor equation to estimate BMR, then multiplies that value by a standard activity factor to estimate TDEE. The result is shown in kcal/day. That unit matters because it gives you a daily average to work from. If you are planning nutrition, think of the output as a reasonable first draft. From there, your job is to observe what happens in real life, then adjust carefully if the trend does not line up with your goal.
How the calculation works
The inputs are straightforward, but they have to be in the right units. Enter your age in years, your weight in kilograms, and your height in centimeters. The calculator also asks for sex because the Mifflin-St Jeor equation uses a different constant for male and female formulas. After BMR is estimated, the calculator applies an activity multiplier to turn a resting-energy estimate into an all-day estimate. That multiplier is meant to stand in for your usual movement pattern across the whole week, not just your workouts.
Here are the formulas used on this page. In the equations below, W is weight in kilograms, H is height in centimeters, and A is age in years.
Mifflin-St Jeor BMR equations:
Total daily energy expenditure:
In plain language, the formula first asks, “How much energy does this body likely use at rest?” and then asks, “How much higher is daily expenditure once normal living and exercise are added?” The result is rounded for readability, but you should still think in ranges rather than single-calorie precision. If your output is 2,430 kcal/day, that does not mean 2,431 is suddenly too much. It means your maintenance calories may plausibly live somewhere around that neighborhood, and your real data will help you narrow it down.
The reason this simple approach is so popular is that it is practical. More advanced measurements exist, but most people do not have easy access to laboratory methods. A well-chosen estimate is often enough to make good nutrition decisions, especially when you are willing to review your progress after two to four weeks and make small, measured changes.
Choosing an activity level
The activity factor is where many people accidentally overshoot or undershoot. A common mistake is to pick a multiplier based on the hardest workout day of the week rather than the average week as a whole. Another common mistake is to ignore non-exercise activity, sometimes called NEAT, which includes walking, standing, chores, commuting, and all the movement that is not formal training. Two people can have the same age, height, and weight, yet end up with different real-world maintenance calories because one person sits most of the day while the other spends hours on their feet.
If you are torn between two categories, a conservative choice is usually smarter at the start. It is easier to raise calories after you notice weight drifting down than it is to begin too high and wonder why maintenance feels suspiciously like a surplus. The table below gives the standard multipliers used by this calculator.
| Activity level | Multiplier | Typical description |
|---|---|---|
| Sedentary | 1.2 | Little or no exercise, mostly sitting, low daily step count |
| Lightly active | 1.375 | Light exercise 1 to 3 days per week, some walking or standing |
| Moderately active | 1.55 | Moderate exercise 3 to 5 days per week, generally active lifestyle |
| Very active | 1.725 | Hard exercise 6 to 7 days per week or consistently high daily movement |
| Extremely active | 1.9 | Very high training volume plus physically demanding work or unusually large daily energy output |
A few judgment calls can help. If you lift three or four times per week but spend most of your day seated, moderately active may still be too high for some people. If you work on your feet all day, regularly walk a lot, and also train, lightly active may be too low even if you are not doing marathon sessions. In other words, the multiplier should represent the whole picture. That is why the optional mini-game later on this page focuses on activity-factor decisions: this is the part of TDEE estimation that often creates the biggest gap between theory and reality.
Worked example
Suppose a 30-year-old male weighs 80 kg, is 180 cm tall, and chooses moderately active with a multiplier of 1.55. The BMR estimate is:
Then TDEE is calculated by multiplying BMR by the activity factor:
Rounded to the nearest calorie, that person would get a TDEE of about 2,759 kcal/day. If their goal were maintenance, they might begin close to that number and watch their weekly average body weight. If their goal were fat loss, they might start with a modest deficit such as 10 to 20 percent below maintenance. If their goal were weight gain or muscle gain, they might start with a smaller surplus, often around 5 to 15 percent above maintenance. The important lesson is that the calculator gives you a usable starting point, not a guarantee that your body will behave exactly as the estimate predicts.
Using your result in real life
Once you have a TDEE estimate, the next step is turning it into an eating plan you can actually follow. For maintenance, many people begin near their estimated TDEE and keep intake fairly consistent for two weeks. If scale weight stays roughly stable when you look at weekly averages, your estimate is probably close. If it trends upward, your real maintenance may be lower. If it trends downward, your real maintenance may be higher. This simple calibration phase is one of the most useful things you can do, because it turns a generic equation into a more personal number.
For fat loss, a moderate calorie deficit is usually easier to sustain than an aggressive one. A common starting point is about 10 to 20 percent below estimated TDEE, or roughly 250 to 500 kcal/day below maintenance for many adults. Smaller deficits often preserve training performance and make hunger easier to manage. Larger deficits can work in some situations, but they also increase the chance that fatigue, cravings, and reduced daily movement will make adherence harder than expected.
For weight gain or muscle gain, the idea is the same in reverse. Start with a small surplus, train productively, and check the trend instead of chasing the biggest possible calorie increase. A surplus that is too large may accelerate weight gain, but not all of that gain will be muscle. In practice, a steady, conservative surplus tends to be easier to control and easier to evaluate.
- Maintenance: begin around your TDEE and watch weekly averages.
- Fat loss: try a 10 to 20 percent deficit, then adjust if the trend is too slow or too fast.
- Weight gain: try a 5 to 15 percent surplus, especially if your priority is leaner progress.
Remember that scale weight is noisy. Glycogen changes, sodium intake, menstrual-cycle effects, soreness from training, and ordinary water retention can all move the scale temporarily without representing a true change in body fat. That is why daily weigh-ins are often most useful when you average them across the week instead of reacting to a single high or low day. You can also use waist measurements, photos, gym performance, and how your clothes fit as additional feedback.
Food quality still matters. TDEE tells you roughly how much energy you need, but it does not tell you which foods will keep you satisfied, support recovery, or fit your routine. Many people find it easier to hit their calorie target when they prioritize enough protein, include fiber-rich foods, and build a repeatable meal pattern around training and work. Those habits do not replace calorie awareness, but they make the calorie target much easier to live with week after week.
Assumptions and limitations
This calculator uses a predictive equation, which means it is built on population data rather than a direct measurement of your metabolism. That matters because individuals can sit meaningfully above or below the prediction while still being perfectly normal. Body composition, genetics, medication use, illness, recovery state, climate, sleep quality, and the amount you unconsciously move during the day can all shift real energy expenditure.
The activity multiplier is also a shortcut. It does not measure your thermic effect of food, your exact exercise calorie burn, or your exact non-exercise activity. It simply bundles them into a practical estimate. That is why the best way to use this tool is to treat it as a hypothesis: start near the result, collect two to four weeks of consistent data, and then make small changes of perhaps 100 to 200 kcal/day if needed. Recalculate after meaningful changes in body weight, training volume, or job activity. If you are dealing with pregnancy, rapid growth, a medical condition, recovery from disordered eating, or a situation requiring clinical nutrition support, it is wise to use individualized professional guidance rather than relying only on a general-purpose calculator.
Common questions
Is TDEE exact? No. It is an estimate of average daily expenditure, not a fixed biological constant. Your true daily burn changes with movement, training volume, sleep, stress, and even the normal tendency to move more when you are well fed or less when you are dieting.
Should you eat exactly your TDEE every day? Not necessarily. Some people prefer the simplicity of the same calories each day, while others eat a little more on training days and a little less on rest days. What usually matters most is the average across the week, because your body does not reset its entire energy balance at midnight.
What if the real-world result does not match the estimate? First, double-check units and measurement accuracy. Weight should be in kilograms and height in centimeters. Then review consistency: cooking oils, snacks, drinks, restaurant meals, and weekend differences can quietly change intake. If you still are not seeing the trend you expect after at least two weeks, adjust calories modestly and reassess. The goal is not to worship the formula; the goal is to use the formula to converge on a number that fits your body.
Does the result stay the same forever? No. As body weight changes, training load changes, or your daily routine changes, your maintenance calories can move too. A new job, a cut in step count, a heavy sports season, or even a long dieting phase can alter the number that works best in practice.
Privacy note: this calculator runs in your browser. The values you enter are used to compute the result shown on the page, and the mini-game stores only a local best score in your own browser using localStorage.
Result: Enter your details and select an activity level, then choose “Calculate TDEE.”
Use the result as a starting estimate, then validate it with two to four weeks of consistent intake and body-weight trends.
Mini-game: Activity Multiplier Rush
This optional canvas mini-game turns the trickiest part of TDEE estimation into a fast, replayable challenge. Instead of changing the calculator math, it trains your eye for one of the biggest judgment calls on the page: picking the right activity factor for a realistic week rather than an idealized one.
Why this matters: the BMR formula is fixed, but the activity multiplier is a judgment call. A realistic weekly average usually beats choosing the lane that matches only your hardest day.