TDEE calculator with the math shown

A TDEE calculator estimates the calories you burn in a day from your resting rate times an activity level. A 30-year-old man, 80 kg and 180 cm, has a resting rate of 1,780 kcal a day. With about an hour of walking a day he burns about 2,850 kcal.

Enter your sex, age, weight and height, then pick the activity level that matches a normal week. Add your body fat percent only if you have measured it. The result shows your TDEE with the arithmetic behind it and a likely range of 10% either way. The rule under it also marks a second estimate from the NASEM 2023 equations.

Quick answer: what does a TDEE calculator show?

TDEE is the calories you burn in a day: your resting rate times an activity level. A 30-year-old man, 80 kg and 180 cm, has a resting rate of 1,780 kcal. With about an hour of walking a day, 1,780 x 1.6 comes to about 2,850 kcal. Eating about that much holds his weight steady.

Key takeaways

• TDEE = resting rate (BMR) x physical activity level (PAL).
• Mifflin-St Jeor is the default equation; use Cunningham (Katch-McArdle) only with a measured body fat percent.
• Treat the result as an estimate with a likely range of 10% either way.
• Weigh yourself daily for a few weeks, average each week, and compare the trend with the estimate.

TDEE calculator worked example

Take the man above: 80 kg, 180 cm, 30 years old. The Mifflin-St Jeor equation for men is 10 x weight in kg + 6.25 x height in cm minus 5 x age, plus 5. That gives 800 + 1,125 minus 150 + 5, or 1,780 kcal a day at rest.

Now multiply by a physical activity level, or PAL. If he mostly sits, PAL 1.2, his TDEE is 2,136 kcal. If he walks about an hour a day, PAL 1.6, it is 2,848 kcal. If he trains hard every day, PAL 2.05, it is 3,649 kcal. The calculator rounds these to the nearest 10 and shows a likely range of plus or minus 10%. The middle case reads as about 2,850, likely 2,560 to 3,130.

A 22-year-old woman, 63 kg and 165 cm, works out at 630 + 1,031.25 minus 110 minus 161, or 1,390 kcal at rest. At PAL 1.6 her TDEE is about 2,220 kcal. The NASEM 2023 equation for a low active woman gives her 2,275 kcal, about 50 kcal higher. That gap is normal, and the section on why calculators disagree explains it.

You can also type a custom PAL if you know yours from a tracker study or a dietitian.

BMR versus TDEE

BMR, or resting energy expenditure, is what your body burns lying still: breathing, circulation, keeping warm, repairing tissue. TDEE adds everything else: exercise, the movement of daily life, and the energy spent digesting food. For the man in the example, BMR is 1,780 kcal and TDEE at PAL 1.6 is 2,848 kcal, so rest is 62.5% of his day's burn.

The PAL method folds all of the non-resting parts into one multiplier. PAL is defined as total energy expenditure divided by BMR, measured in real people over whole days. So the multiplier already contains daily movement and the thermic effect of food. The calculator does not add a separate allowance for digestion on top, because that would count it twice.

How to choose your activity level

Pick the level whose example day looks like your average week, and when you are torn, pick the lower one. The NASEM report calls choosing a category "the most challenging part" of the estimate and notes that step counts and questionnaires correlate only weakly with measured PAL.

The labels mislead when they describe gym sessions alone. The FAO report gives a useful scale: one hour a day of jogging, cycling or sport raises a sedentary person's PAL from about 1.55 to about 1.75. Three workouts a week is less than that, so a desk job plus three hard workouts may still sit below the Active level. For the 1,780 kcal man that hour a day is worth 356 kcal, the gap between 2,759 kcal at PAL 1.55 and 3,115 kcal at 1.75.

If your job keeps you on your feet all day, start at Active even if you never exercise. Black et al. 1996 put standing work with substantial movement at PAL 1.8 to 1.9.

Why TDEE calculators disagree

Two choices drive the spread: the resting equation and the activity multiplier. The multiplier matters more. Our man at the common 1.55 multiplier gets 2,759 kcal; at the NASEM active value of 1.75 he gets 3,115 kcal, 356 kcal more from the same equation.

The NASEM 2023 EER equations skip the two-step method and predict total expenditure directly from age, height, weight and category. For the same man they give 2,726 kcal if inactive and 3,126 kcal if active. Against Mifflin-St Jeor times PAL, that is 234 kcal higher at the inactive level and 11 kcal higher at the active level. The calculator shows both so you can see the spread before you pick a target.

Resting equations differ less. The same man at 20% body fat has a fat-free mass of 64 kg, and Cunningham gives 1,752 kcal against 1,780 from Mifflin-St Jeor, about 28 kcal apart. The 1919 Harris-Benedict equation overestimated measured resting rate by 5% in the Mifflin study. A 1984 reevaluation put it at about plus or minus 14%, so the tool does not offer it.

How accurate is a TDEE calculator

Treat the number as the middle of a range. Frankenfield 2005 found that Mifflin-St Jeor landed within 10% of measured resting rate in more people than Harris-Benedict, Owen or the WHO/FAO/UNU equations, and that notable individual errors remain. That supports a plus or minus 10% band, which is what the tool shows. It does not support a claim that the calculator is accurate to 10% for you.

The NASEM equations report their own error. For women, the standard error of a predicted value is 241 kcal a day, and about 68% of people with the same inputs fall within that of the prediction. The root mean square error is 339 kcal a day for men and 246 for women. Two people who type the same numbers can burn several hundred calories apart, so check the estimate against the scale (below) before you trust it.

How to use the number

To hold your weight, eat near your TDEE. To lose, the tool offers cuts of 250, 500 or 750 kcal a day below it. To gain, it offers the same amounts above. A 500 kcal cut from 2,850 gives a target of 2,350 kcal.

The tool never shows a target under 1,000 kcal a day, which is the NIH Body Weight Planner's warning level. It flags any target under 1,200 kcal for a woman or 1,500 for a man with a note to check with a clinician. Those two floors are common clinical guidance; we could not trace them to a study. If a cut would push you under them, choose a smaller cut and a longer timeline.

Protein has its own target that does not scale with calories; our protein calculator works it out from body weight and goal.

What a calorie cut does over time

The 3,500 kcal per pound rule is fine for the first few weeks. A 500 kcal daily cut over 28 days is 14,000 kcal, or about 4 lb. The tool uses this rule for the short term only and says so.

Over months the rule overstates loss, because your expenditure falls as your weight falls. Hall 2011 gives a better long-run rule. Each permanent change of about 10 kcal a day leads to an eventual change of about 1 lb (about 24 kcal a day per kg). A permanent 500 kcal cut therefore ends at about 50 lb lighter, about half of it within a year and about 95% within three years. People with more body fat lose more for the same cut and take longer to level off.

This is also why your TDEE changes as you lose. Each new weight has a lower resting rate, so recalculate after any sizable change, and expect each later pound to come slower than the last.

Check the estimate against the scale

Weigh yourself daily under the same conditions for a few weeks and average each week. Then compare the trend with what the estimate predicted.

Take the man above. He estimates 2,850 kcal and eats 2,350, a planned 500 kcal cut. Over 28 days he expects about 4 lb off. He loses 2 lb. Two pounds is about 7,000 kcal over 28 days, so his real deficit was about 250 kcal a day. His real TDEE is about 2,350 + 250 = 2,600 kcal. To get back to a 500 kcal cut he drops intake to about 2,100.

This measured number beats any equation, because it is your own expenditure at your own weight. Repeat the check after any sizable change in weight, since the answer drifts as you change.

Who the equations fit

Mifflin and colleagues built their equation on healthy adults aged 19 to 78, at normal weight and with obesity. The NASEM equations cover adults 19 and older, and the tool also accepts age 18, with a note in the method box. Outside that group the estimate is less reliable. Pregnancy and breastfeeding use separate terms the tool does not include, and growing teenagers need different equations. Someone with very high muscle mass will have a higher resting rate than a weight and height equation predicts. If you have measured body fat, the Cunningham option handles the muscle case better because it works from fat-free mass.

Frequently asked questions

Should I eat at TDEE or BMR? Eat relative to TDEE. BMR is what you burn lying still, so eating at BMR is a cut equal to your whole activity level. For the example man that is a 1,068 kcal cut, far past the 750 kcal preset.

Is a maintenance of 1,400 to 1,500 kcal realistic for a small woman? It can be. A 70-year-old woman, 70 kg and 157 cm, has a resting rate of about 1,170 kcal. If she mostly sits (PAL 1.2) her TDEE is about 1,400 kcal, and at the inactive level (1.4) about 1,640.

What is a good TDEE? There is no good or bad value. TDEE describes how much you burn, and it rises with body size, youth, male sex and movement. A higher number only means a higher intake holds your weight.

How do I increase my TDEE? Move more hours of the day. The FAO figure of an extra hour of jogging, cycling or sport moving PAL from about 1.55 to 1.75 is the clearest sourced example. Our steps to calories page turns a step count into a calorie figure.

Does the calculator include the thermic effect of food? Yes, inside the PAL. The multiplier is measured total expenditure divided by resting rate, so digestion and daily movement are already in it.

Which formula is best: Mifflin-St Jeor, Harris-Benedict or Katch-McArdle? Mifflin-St Jeor by default, on the Frankenfield 2005 comparison. Use the Cunningham (Katch-McArdle) option only when you have a measured body fat percent, because a guessed percent adds more error than it removes.

Conclusion

Your TDEE is a starting estimate for maintenance calories. Plan around it, then check it against your weekly weight average and adjust. This is general information, not medical advice; a doctor or registered dietitian can set targets for a medical condition.

From our cookbooks: once you have a calorie target, our chicken cookbook gives you meals to build it from. See Chicken Recipes Cookbook.