How to work out your TDEE by hand in two minutes
TDEE is the calories your body burns in a whole day. You can work out your own number on paper in two minutes with one trusted rule, then check it against Burnie.
You typed your details into an online TDEE calculator. A number popped up. But you do not know where it came from. Good news: the maths is short. You can do it yourself on paper in two minutes. Once you know the rule, the number feels less like magic and more like yours.
The one rule: Mifflin-St Jeor
There is one trusted rule for resting calories. It is called the Mifflin-St Jeor equation. It guesses the calories your body burns lying completely still. This number is your BMR, or basal metabolic rate (the energy to keep you alive at rest). The rule works for healthy adults. Women: (10 x weight in kg) + (6.25 x height in cm) - (5 x age in years) - 161 Men: (10 x weight in kg) + (6.25 x height in cm) - (5 x age in years) + 5 It looks scary, but it is just four small sums.
Work it out in five steps (example: Priya)
Pick your activity factor (Priya's TDEE)
A TDEE calculator gives you your exact daily burn.
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No rule is perfect. Even the best resting-calorie rule can miss by about 10%. So Priya's 1667 could really sit anywhere from about 1500 to 1830. That is why a TDEE number is a smart starting guess, not a perfect measurement. After two weeks of logging your food and weight, your own body fine-tunes the guess. Burnie is FREE and carries this daily maths for you, but doing it once by hand shows you why the number is what it is.
The bottom line
Doing your TDEE by hand once turns a mystery number into your number. You also see something juicy: moving from a desk day to a daily-walk day adds about 240 kcal for Priya, roughly two extra rotis of headroom. Burnie is FREE and does this maths for you every day. But now you know the rule behind the number. Work it out once on paper. Then let Burnie carry the daily maths, and let your own two-week log tell you the truth.