TDEE and calorie targets
Mifflin-St Jeor, then an activity multiplier. The result is on the page before you type anything, with the guide's own worked example in the boxes, and the arithmetic is shown so you can check it.
Maintenance calories
Example1,910kcal a day
What you burn in a day at lightly active. It is an estimate with real error in it, not a measurement.
10x65 + 6.25x168 - 5x30 - 161 = 1389 BMR, x1.375 = 1910
Cross-check: the calories-per-kg table in the guide puts a 65 kg lightly active person at 1,950 to 2,145. A spread of 300 to 400 calories between calculators for the same person is entirely normal. The activity multiplier accounts for more of that than the equation does.
Calorie targets
- Fat loss, moderate-20%1,530 kcal
- Fat loss, conservative-12%1,680 kcal
- Maintenance1,910 kcal
- Muscle gain, lean+8%2,065 kcal
- Muscle gain, faster+15%2,195 kcal
No target below 1,200 kcal is printed. NHS guidance is that intakes under that want medical supervision, so the honest answer is a smaller deficit or a longer timeline rather than a smaller number.
Equation constant
Mifflin-St Jeor was derived with two constants, plus 5 and minus 161. There is no third, and this site is not going to invent one and put a number behind it.
Multiplier 1.375. This is where estimates go wrong. Most people select a level above their actual one, because training three times a week feels active even when the other 165 hours of the week are spent sitting.
Signed in, the weight box opens in your unit and the activity level starts from the training days on your profile.
Your height, age and the constant the equation uses are not on your profile, so they are not filled in. Nothing you type here is stored.