Estimates only. Talk to a doctor or registered dietitian before acting on these numbers for medical reasons.
What is TDEE?
TDEE, total daily energy expenditure, is every calorie you burn in a day. It has three parts:
- At rest. Keeping you alive: heart, brain, organs. This is your BMR, and it is most of the total.
- Movement. Steps, chores, workouts. This part changes the most from person to person.
- Digestion. Breaking down food costs energy too, more for protein than for fat.
Eat at your TDEE and your weight holds. That is why people also call it maintenance calories.
How the calculator works
TDEE = (370 + 21.6 × lean kg) × activity × digestion
At rest comes from the Cunningham equation, which works from lean mass: your weight minus your fat. Muscle burns more at rest than fat does, so two people at the same weight but different body fat get different numbers. The lean body mass calculator shows yours.
An example: a 176 lb man at 20% body fat who walks 5,000 to 8,000 steps and lifts once or twice a week. His lean mass is about 141 lb, he burns about 1,750 calories at rest, and his maintenance is about 2,456 calories a day.
Activity comes from your steps and your workouts together:
| Steps a day | No workouts | 1–2 a week | 3–4 | 5+ |
|---|---|---|---|---|
| Under 5k | 1.20 | 1.30 | 1.30 | 1.45 |
| 5–8k | 1.30 | 1.30 | 1.45 | 1.45 |
| 8–12k | 1.30 | 1.45 | 1.45 | 1.55 |
| 12k+ | 1.45 | 1.45 | 1.55 | 1.55 |
Strength and sports workouts add up: two lifting sessions and two runs a week count as 3 to 4. Digestion is 1.08 for takeout and ready meals, 1.10 for home cooking with whole foods, and 1.15 for a very high protein, high fiber diet.
Sports workouts
The activity level stops at 1.55, so a lot of running or cycling on top of lifting would not show up there. Sports get their own line. The calculator counts a sports session as one hour at a moderate effort: about 7.5 times your resting rate, the average of running at 6 mph, cycling at 12 to 14 mph, slow lap swimming and tennis in the 2024 Compendium of Physical Activities. It counts only the calories above what you would burn at rest in that hour. For 176 lb that is about 520 calories a session.
The headline number spreads those calories over all seven days. In the app you eat them on the day you train instead: Fuel adds them to that day's budget.
Why do TDEE calculators give different numbers?
They use different formulas for resting burn and different activity levels. Many calculators go up to 1.9 for "extremely active". This one tops out at 1.55, and with digestion the total multiplier runs from 1.30 to 1.78. That is on purpose. People tend to report more exercise than they do, and a plan that starts a little low is easier to correct than one that starts high.
TDEE and maintenance calories questions
What is the difference between TDEE and BMR?
BMR is what you burn at complete rest. TDEE adds everything else: walking, workouts, and digesting food. In this calculator TDEE is 1.30 to 1.78 times BMR. Eat at your TDEE and your weight holds; eat below it and you lose.
Do TDEE and maintenance calories include exercise?
Yes. Steps and workouts set your activity level. Sports sessions like runs, rides, swims and tennis also get their own line, because a long session burns more than the activity level can hold. The calculator spreads those calories over the week, and also shows what you burn on a sports day.
Is maintenance calories the same as TDEE?
Yes. Both mean the calories you burn in a day, so eating that many holds your weight.
Why doesn't it ask for my height and age?
Because it works from lean mass, which comes from your weight and body fat. A 1991 review of resting metabolism studies found that lean mass explains 65 to 90% of the difference in resting burn between adults. Formulas like Mifflin-St Jeor use height and age because they do not know your lean mass.
Does my TDEE change as I lose weight?
Yes, it goes down. A smaller body costs less to move, and the body also adapts. In studies, people who held a weight loss of 10% or more burned 20 to 25% less a day, 10 to 15% less than their new size explains. Recalculate every few pounds, or let the Deficit app measure it from your weekly trend.
Can I calculate TDEE without knowing my body fat?
Yes. Pick the body type that looks most like you and the calculator uses the middle of its range. A few points off on body fat changes the result by less than you might expect: 5 points at 176 lb moves maintenance by about 120 calories.
Is this the same as the Katch-McArdle formula?
Yes. The Cunningham 1991 equation, 370 + 21.6 × lean mass in kg, gives the same numbers as the Katch-McArdle formula that many calculators use.
How accurate is a TDEE calculator?
Any formula is a starting estimate, and your own burn can be higher or lower. The way to get your real number is to eat a steady amount, weigh yourself daily, and watch the trend for two to three weeks. The Deficit app does this for you each week.
Sources
- Body composition as a determinant of energy expenditure: a synthetic review and a proposed general prediction equation. Cunningham JJ. Am J Clin Nutr. 1991. (PubMed)
- 2024 Adult Compendium of Physical Activities: a third update of the energy costs of human activities. Herrmann SD, Willis EA, Ainsworth BE, et al. J Sport Health Sci. 2024. (PubMed)
- Adaptive thermogenesis in humans. Rosenbaum M, Leibel RL. Int J Obes. 2010. (free full text, PMC)
- Non-exercise activity thermogenesis (NEAT). Levine JA. Best Pract Res Clin Endocrinol Metab. 2002. (PubMed)
- Discrepancy between self-reported and actual caloric intake and exercise in obese subjects. Lichtman SW, Pisarska K, Berman ER, et al. N Engl J Med. 1992. (PubMed)