What is TDEE, and how is it different from BMR?
- Think of your body as a car. BMR is the fuel it burns idling. TDEE is the fuel for the whole day's driving.
- BMR is mostly fixed by your body. TDEE changes with how you live.
- Two people of the same height and weight can need very different amounts of food.
| Activity level | Factor | BMR as a share of TDEE |
|---|---|---|
| Sedentary | 1.2 | ≈ 83% (1 ÷ 1.2) |
| Extra active | 1.9 | ≈ 53% (1 ÷ 1.9) |
How to calculate TDEE and BMR, step by step
Step 1. Calculate BMR with Mifflin-St Jeor.
Women: BMR = 10 × weight (kg) + 6.25 × height (cm), 5 × age, 161
Men: BMR = 10 × weight (kg) + 6.25 × height (cm), 5 × age + 5
Woman, 30, 160 cm (5 ft 3 in), 60 kg (132 lb): 600 + 1,000 to 150 to 161 = 1,289 kcal
Step 2. Multiply by your activity factor.
| Activity level | Meaning | Factor |
|---|---|---|
| Sedentary | Desk job, little or no exercise | 1.2 |
| Lightly active | Walks or light exercise 1 to 3 days a week | 1.375 |
| Moderately active | Exercise 3 to 5 days a week | 1.55 |
| Very active | Hard exercise 6 to 7 days a week | 1.725 |
| Extra active | Physical job, or training twice a day | 1.9 |
TDEE = BMR × activity factor
Lightly active: 1,289 × 1.375 = 1,772 kcal a day
Source: Mifflin et al., American Journal of Clinical Nutrition, 1990. Measured 498 adults aged 19 to 78. The older Harris-Benedict equation (1919) ran about 5% high. The tool above also offers Harris-Benedict (1984 revision) and Katch-McArdle (needs body fat %) for comparison.
Is TDEE calculated differently for women?
- Same equation, different final constant: women subtract 161, men add 5.
- Same height, weight and age: a woman's BMR is exactly 166 kcal lower. The example above as a man: 1,455 kcal instead of 1,289.
- Those two constants came from 247 women and 251 men in the 1990 study.
How many calories do I need a day?
There is no single number. Your answer is your TDEE: eat at it and your weight holds. The table below gives a feel for the range.
| Activity level | Woman, 30, 5 ft 3 in, 132 lb | Man, 30, 5 ft 7 in, 154 lb |
|---|---|---|
| Sedentary | 1,547 kcal | 1,941 kcal |
| Lightly active | 1,772 kcal | 2,224 kcal |
| Moderately active | 1,998 kcal | 2,507 kcal |
| Very active | 2,224 kcal | 2,790 kcal |
| Extra active | 2,449 kcal | 3,073 kcal |
- "How many calories should I burn a day?" You already burn your TDEE. Workouts are inside the factor.
- Do not add exercise calories on top of TDEE. You would count them twice.
How many calories should I eat to lose weight?
- As arithmetic: below TDEE loses, above it gains.
- Mayo Clinic (updated September 2024): cutting about 500 calories a day may lose about half a pound to one pound a week, varying with your body, sex and activity level (source).
- The tool shows two marks, TDEE minus 10% and minus 20%, so you see the gap as a number.
- The macro ranges (protein, carbs, fat) in the tool follow the Institute of Medicine's adult distribution ranges, not a formula of our own.
From coaching experience: people who cut below their BMR tend to feel tired, sleep badly and quit within weeks. The ones who lose and keep it off usually start moderate and adjust to how their body responds.
Why does the scale not move even when I eat below TDEE?
The formula gives an average. Your body is not an average. The three situations I see most often:
- Real portions higher than estimated. A bowl of phở or an iced milk coffee can be off by a few hundred calories.
- An activity level chosen one step too high.
- Water retention hiding fat that has already gone.
A few weeks below TDEE and nothing moved? Cutting further is rarely the answer. That is the moment to find your own reason, the first step of how Young Group works.
Your TDEE is the starting point, not the final answer
Knowing your TDEE means you are no longer eating blind. But the number cannot tell you why your body responds the way it does, or which plan you can actually keep.
