BMR, TDEE, and Activity Level: How the Numbers Connect
Basal metabolism is not an eating target, and activity is the least certain input.
What it does and when to use it
BMR estimates energy for basic functions at rest. TDEE adds activity, digestion, and daily movement, making it more useful for planning.
What information to enter
Enter current data and choose activity based on a normal week, not the most active day.
How to understand the result
The gap between BMR and TDEE is estimated. A desk job with three workouts is not automatically “very active.”
Recommended step-by-step workflow
- Check the assumptionsBMR estimates energy for basic functions at rest. TDEE adds activity, digestion, and daily movement, making it more useful for planning.
- Use matching unitsEnter current data and choose activity based on a normal week, not the most active day.
- Compare with another scenarioThe gap between BMR and TDEE is estimated. A desk job with three workouts is not automatically “very active.”
Short example
A BMR of 1,600 multiplied by 1.45 gives an estimated TDEE of 2,320 calories.
Common mistakes
- Eating at BMR indefinitely as though it were maintenance.
- Double-counting activity already included by a tracker or calculator.
Frequently Asked Questions
Which formula is best?
No formula is perfect; Mifflin-St Jeor is common, but real trends should calibrate it.
Why does a watch differ?
Wearables also use models and can over- or underestimate activity.
Are my personal inputs saved?
No. The calculators and guides are designed for quick browser use without storing your personal input values.