Maintenance Calories: How to Find the Number Your Body Actually Runs On

What Are Maintenance Calories?

Maintenance calories are what you'd need to eat, averaged over a week or two, for your weight to stay where it is. The technical name is total daily energy expenditure, or TDEE. Eat above it and you gain weight. Eat below it and you lose.

That number is built from three things. Your resting metabolic rate, the energy your body uses just keeping you alive, is the biggest share for most people. Digesting food costs a little more. Movement makes up the rest, and it varies the most between people because it covers both workouts and all the walking, standing, and fidgeting you do without thinking.

Every weight goal is measured against maintenance. If your estimate is 300 calories too high, the 500-calorie deficit you planned is really 200 calories, and you'll lose weight at less than half the rate you expected.

How Do You Calculate Maintenance Calories?

Most calculators, including the Forkd calorie calculator, use a two-step method.

Step 1: Estimate resting energy with the Mifflin-St Jeor equation.

• Men: (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
• Women: (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161

The equation comes from a 1990 study that measured resting energy expenditure in 498 healthy adults aged 19 to 78, including both normal-weight and obese participants. In that same study, the older Harris-Benedict equations overestimated measured values by about 5 percent.

Step 2: Multiply by an activity factor.

Activity level	Description	Multiplier
Sedentary	Little or no exercise	1.2
Lightly active	Exercise 1 to 3 days a week	1.375
Moderately active	Exercise 3 to 5 days a week	1.55
Very active	Exercise 6 to 7 days a week	1.725

Take a 35-year-old woman who is 165 cm (5'5") and 68 kg (150 lb). Her resting estimate is 680 + 1,031 − 175 − 161, or about 1,375 calories. If she's lightly active, her estimated maintenance is 1,375 × 1.375, which comes to about 1,890 calories.

Now a 35-year-old man who is 178 cm (5'10") and 82 kg (181 lb). His resting estimate is 820 + 1,112.5 − 175 + 5, or about 1,763 calories. At moderately active, that becomes 1,763 × 1.55, or about 2,730 calories.

How Accurate Are Maintenance Calorie Calculators?

They're a reasonable starting point, but the error for any one person can be large.

A 2005 systematic review for the American Dietetic Association compared the four most widely used equations and found Mifflin-St Jeor to be the most reliable. It predicted resting metabolic rate within 10 percent of the measured value in more people than any of the others, and it had the narrowest error range. The same review still flagged "noteworthy errors" when the equation is applied to individuals, and pointed out that older adults and US ethnic minorities were underrepresented in the studies used to build and validate these equations.

Ten percent sounds small until you run the numbers. For someone whose true maintenance is 2,200 calories, a 10 percent miss is 220 calories a day in either direction, before the activity multiplier adds its own guesswork.

That multiplier is the shakier of the two steps. An office worker who lifts three times a week and a nurse who spends 12-hour shifts on her feet might both tick "moderately active," and they can burn very different amounts of energy.

Does Exercise Raise Your Maintenance Calories as Much as You'd Think?

Often less than a calculator assumes, at least at the high end.

In a 2016 study, Herman Pontzer and colleagues measured total energy expenditure with doubly labeled water, the gold-standard method for people going about normal life, in 332 adults from five populations. They compared it with physical activity recorded by accelerometers. Energy expenditure rose with activity at the lower end of the range. At higher activity levels it plateaued, as though the body were saving energy elsewhere to keep the daily total within a narrow band. The researchers called this a constrained energy expenditure model.

Going from sedentary to moderately active probably raises your maintenance in a meaningful way. Going from moderately active to training twice a day may raise it by less than the multiplier table suggests. That's no reason to skip exercise, which does a great deal for health and body composition. It is a good reason not to eat back every calorie your treadmill says you burned.

A related finding surprised a lot of people. A 2021 study in Science pooled doubly labeled water measurements from people aged 8 days to 95 years and found that, once adjusted for fat-free mass, daily energy expenditure stayed stable from about age 20 to 60 and only began to decline after 60. The weight many people gain in their 30s and 40s probably has more to do with how they move and eat than with a metabolism that quietly slowed down.

Why Do Maintenance Calories Drop After Weight Loss?

The first reason is simple. A smaller body needs less energy to run and to carry around, so maintenance falls along with your weight. Any decent calculator accounts for this as long as you update your weight.

The second reason is adaptive thermogenesis, which means energy expenditure falling further than the change in body size would explain. The most striking data on it comes from a National Institutes of Health follow-up of contestants from the TV show The Biggest Loser. Fourteen of the original 16 contestants were measured again six years after the competition.

During the 30-week show they had lost an average of 58.3 kg, and their resting metabolic rate had dropped by 610 calories a day. Six years later they had regained an average of 41 kg, yet their resting metabolic rate was still 704 calories a day below where it started. After adjusting for body composition and age, it ran about 499 calories a day lower than expected.

That's an extreme case of extreme weight loss. The authors described the slowdown as a proportional response to the ongoing effort to keep weight off, which suggests a moderate diet should cause a much smaller effect than losing 58 kg in 30 weeks on television. Either way, re-check your maintenance whenever your weight has moved by a few kilos, and trust recent data over a number you calculated months ago.

How Do You Find Your Real Maintenance Calories From Tracking Data?

Use a calculator for the first guess, then let your own numbers correct it. It takes two to three weeks.

1. Log everything you eat and drink for 14 to 21 days. Include weekends, since intake tends to run higher then, as we covered in why you overeat on weekends.
2. Weigh yourself every morning after using the bathroom and before eating or drinking.
3. Compare weekly averages instead of single days. Daily weight can swing by a kilo or more from water, salt, and digestion. The difference between your first week's average and your last week's average is the signal you want.
4. Do the arithmetic. Estimated maintenance = average daily intake + (average weekly weight loss in kg × 7,700 ÷ 7). If you gained weight, subtract instead. If you weigh in pounds, use 3,500 in place of 7,700.

Say you averaged 2,100 calories a day and your weekly average dropped by 0.4 kg per week. That's 0.4 × 7,700 ÷ 7, or 440 calories a day of deficit, which puts your maintenance at roughly 2,540 calories.

A few things can throw the result off:

• The first week of a new diet. Cutting carbs or calories releases water stored alongside glycogen, so early losses exaggerate fat loss. If you've just started dieting, leave the first week out of the calculation.
• The menstrual cycle. Water retention can hide a real trend for several days. Comparing weeks at the same point in your cycle, or using a full three to four weeks of data, gives a cleaner read.
• Gaps in your log. Missing cooking oil, sauces, and bites taken while cooking makes your calculated maintenance come out too low. Our piece on why your food log is lying to you covers the usual blind spots.

The 7,700 figure is a rough energy value for a kilogram of body weight, and it works well over a few weeks. Over months, weight loss slows for the reasons in the previous section, which is why our guide on how many calories to eat to lose weight explains where the old 3,500-calorie rule breaks down.

Should You Ever Eat at Maintenance on Purpose?

Maintenance phases are underused. They give you a break from hunger and diet fatigue, and they let you practise the eating habits you'll rely on once the diet is over.

Jeff Nippard, the evidence-focused fitness coach, made the case for diet breaks on X:

Although it may seem counterintuitive, diet breaks can actually help with increasing the effectiveness of your diet. If you are experiencing diet fatigue, taking ~2 weeks to eat at maintenance calories can go a long way in keeping motivation and adherence high.

— Jeff Nippard (@JeffNippard) October 17, 2022

The best-known trial behind this idea is the MATADOR study, published in 2018. Fifty-one men with obesity were randomly assigned to either 16 weeks of continuous dieting or the same 16 weeks of dieting broken into two-week blocks, alternating with two-week blocks at maintenance, for 30 weeks in total. During the diet phases, both groups ate 67 percent of their maintenance calories.

Among the men who completed the program as planned, the intermittent group lost 14.1 kg against 9.1 kg for the continuous group, including 12.3 kg of fat against 8.0 kg. Weight barely moved during the maintenance blocks. After adjusting for changes in body composition, resting energy expenditure also fell less in the intermittent group.

It was a small trial in men only, and the intermittent group spent nearly twice as long on the calendar, so it's encouraging rather than conclusive. It does suggest that two planned weeks at maintenance don't have to cost you progress.

How Does Forkd Help You Find Your Maintenance Calories?

The free Forkd calorie calculator uses Mifflin-St Jeor with the four activity levels in the table above, then adjusts your target for weight loss, maintenance, or muscle gain. That gives you the starting estimate.

The correction step depends on a food log you can keep up for three weeks. In the Forkd app you log a meal from a photo, a voice note, or a line of text, and hidden calorie detection accounts for the cooking oil, dressings, and sauces that make logged intake come out lower than what you really ate. More accurate intake data gives you a more accurate maintenance number. Search the App Store for "AI Calorie Tracker: Forkd".

Frequently Asked Questions

Are maintenance calories the same as TDEE?

For practical purposes, yes. TDEE (total daily energy expenditure) is how many calories you burn in a day, and maintenance calories are how many you need to eat to match it. Eating at your TDEE over several weeks keeps your weight stable.

Is BMR the same as maintenance calories?

No. BMR, and the closely related resting metabolic rate, only covers the energy you burn at complete rest. Maintenance adds the cost of digesting food and all your daily movement on top. Eating at your BMR puts almost everyone in a calorie deficit, often a large one.

How often should I recalculate my maintenance calories?

Recalculate whenever your weight changes by around 5 percent, your activity level changes substantially, or your weight stops responding the way you'd expect for two to three weeks. For someone losing weight steadily, that often works out to every couple of months.

Why am I not losing weight eating below my calculated maintenance?

Usually it's one of two things. The calculator may have overestimated your maintenance, which is common given the error range of the equations and activity multipliers. Or your log may be missing calories, often from cooking fats, drinks, and small bites. Two to three weeks of careful logging and daily weigh-ins will show which one it is.

Do maintenance calories go down with age?

Less than most people assume, at least until around 60. A 2021 study in Science found that energy expenditure adjusted for fat-free mass holds steady between about 20 and 60, then declines. What often changes with age is muscle mass and daily activity, and strength training and staying active can offset both.

Can you lose fat while eating at maintenance?

Some people can, particularly those new to strength training, people returning after a long break, and those with more body fat. Eating enough protein and training with progressive overload makes body recomposition possible at maintenance, though the scale moves slowly because muscle gain offsets the fat loss. See how much protein you need per day for targets.

Key Takeaways

• Maintenance calories (TDEE) are the intake that keeps your weight stable over time.
• Estimate them with the Mifflin-St Jeor equation multiplied by an activity factor from 1.2 (sedentary) to 1.725 (very active).
• Mifflin-St Jeor is the most reliable of the common equations, but it still misses by more than 10 percent for some people.
• At high activity levels, energy expenditure rises less than simple multipliers assume.
• To find your real number, log intake and weigh daily for two to three weeks, then adjust using about 7,700 calories per kilogram of trend change.

References

1. Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. (1990). A new predictive equation for resting energy expenditure in healthy individuals. American Journal of Clinical Nutrition, 51(2), 241-247. doi.org
2. Frankenfield D, Roth-Yousey L, Compher C. (2005). Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: a systematic review. Journal of the American Dietetic Association, 105(5), 775-789. doi.org
3. Pontzer H, Durazo-Arvizu R, Dugas LR, et al. (2016). Constrained total energy expenditure and metabolic adaptation to physical activity in adult humans. Current Biology, 26(3), 410-417. doi.org
4. Pontzer H, Yamada Y, et al. (2021). Daily energy expenditure through the human life course. Science. doi.org
5. Fothergill E, Guo J, Howard L, et al. (2016). Persistent metabolic adaptation 6 years after "The Biggest Loser" competition. Obesity, 24(8), 1612-1619. doi.org
6. Byrne NM, Sainsbury A, King NA, Hills AP, Wood RE. (2018). Intermittent energy restriction improves weight loss efficiency in obese men: the MATADOR study. International Journal of Obesity, 42(2), 129-138. doi.org