Weight-based vs lean-mass estimates
Weight-based equations treat two 195 lb men the same even if one is lean and muscular and the other is not. For the example above (moderately active), Mifflin-St Jeor gives about 2,807 calories a day. Using Katch-McArdle instead, the estimate is about 3,179 at 12% body fat and 2,646 at 30% body fat.
If your body-fat % is known and noticeably different from average, the lean-mass figure may fit you better. If not, stick with Mifflin-St Jeor.
What moves the estimate most
Starting from a 38-year-old man, 5′10″, 195 lb, at the selected activity level (TDEE about 2,807 calories):
| Change | Calories/day |
|---|---|
| 10 lb more body weight | +70 |
| 2 inches taller | +49 |
| 10 years older | −78 |
| One activity level higher | +317 |
Picking an honest activity level
The activity factor is where most estimates go wrong. A desk job plus three gym sessions a week is usually “lightly” or “moderately” active, not “very active”. “Very” and “extra active” fit people who train hard almost every day or whose job is physically demanding. When in doubt, choose the lower level and let your weight trend tell you if it’s too low. Reference tables for men from 140 lb to 250 lb show how much the level matters.
Frequently asked questions
How many calories does an average man burn a day?
It depends heavily on size and activity, so a single “average” is not very useful. As one example, a 38-year-old man who is 5′10″, 195 lb and moderately active comes out around 2,807 calories a day by Mifflin-St Jeor. Enter your own numbers above for a personal estimate.
Which formula is best for men who lift weights?
If you carry more muscle than average and know your body-fat %, Katch-McArdle is worth comparing, because weight-based equations can underestimate needs for very muscular people. Your weight trend over a few weeks is the final check.
Do I count my workouts in the activity level or add them separately?
The activity level already includes typical exercise, so don’t add workout calories on top unless you choose “sedentary” and track exercise separately. Doing both counts the same activity twice.
Why does TDEE go down with age?
All the equations subtract a little for each year of age, reflecting an average decline in resting energy use that is partly linked to changes in muscle mass. Staying active and strength training can help maintain muscle.