Guide
BMR vs TDEE: Which Calorie Number Should You Use?
BMR estimates energy needed for basic functions at rest. TDEE, or total daily energy expenditure, includes the rest of your day: movement, exercise and processing food. For understanding maintenance calories, the daily total is the relevant starting estimate—not the resting number alone. Neither figure is an exact measurement of your individual needs.
Why is maintenance higher than BMR?
Your body uses energy for breathing, circulation and maintaining body temperature even while resting. It also spends energy walking around, doing chores, exercising and digesting food. That is why the daily total is higher than the resting estimate.
The Calorie Calculator uses the Mifflin–St Jeor equation for its displayed BMR estimate, then multiplies the unrounded result by an activity factor to estimate maintenance. It does not measure metabolism or track actual activity.
A worked example you can check
Select Male, enter age 30, weight 70 kg and height 175 cm, and choose “Little or no exercise”. The equation is 10 × 70 + 6.25 × 175 − 5 × 30 + 5 = 1,648.75. The tool rounds its displayed BMR to 1,649 kcal/day.
Multiplying 1,648.75 by 1.2 gives 1,978.5, displayed as 1,979 maintenance calories. With moderate exercise, the 1.55 factor gives about 2,556. The higher figure reflects a different activity assumption, not a change in the resting equation.
Should you eat exactly your BMR?
BMR is not a personalized eating target or a universal safe minimum intake. It leaves out much of everyday energy use. Choosing it simply because it is the smaller number can lead to an unsuitable plan.
The tool also shows rough loss and gain estimates by subtracting or adding 500 calories to maintenance. Those are simplified comparisons, not a prescription or a promise of a specific weekly weight change.
How should you choose activity level?
Consider your whole routine, including a physical job and everyday movement, rather than your hardest workout. Activity descriptions are broad estimates. If exercise is already represented in the chosen factor, adding all workout calories again can double-count activity.
Muscle mass, medical conditions, medications and changing routines can affect needs. Use the result as a planning estimate. Young people, pregnant or breastfeeding people, and anyone managing a medical condition or eating disorder should seek individualized professional advice rather than relying on this calculator.
Sources and further reading
Try it yourself
Put this guide into practice with our free Calorie Calculator — no sign-up, no download.
Open the Calorie Calculator