Activity level is one of five details the calorie calculator asks for, alongside your age, assigned sex, height and weight. Together they produce an estimate of how many calories your body uses in a day.
Why activity level changes the number
- Movement is the part that varies. Your body uses energy just to keep running. Everything you do on top of that adds to the total, and activity level is how the calculator accounts for the second part.
- It is not only workouts. Standing at work, walking the dog, carrying shopping and doing the housework all count. For a lot of people that everyday movement adds up to more than their training does.
- It usually moves the estimate most. Of the five inputs, this is the one that shifts the daily figure most. The gap between a quiet week and an active one is large.
In practice, your age, assigned sex, height and weight are used together to estimate the calories your body uses at rest. That figure is then scaled by your activity level to give the daily number you see.
Choosing a level
Pick the level that describes your whole week, not just your best day. The calculator offers five:
- Sedentary. Little or no exercise, and mostly sitting.
- Lightly active. Light daily activity, or light exercise 1 to 3 days a week.
- Moderately active. Moderate exercise 3 to 5 days a week.
- Very active. Hard exercise 6 to 7 days a week, or a physical job.
- Extra active. Intense daily training, or a very physically demanding job.
If you sit between two levels, pick one and then run the calculator again with the other. Comparing the two numbers shows you how much the choice is worth.
What the number is, and what it is not
The result is an estimate, not a measurement. It is a starting point to track against and adjust from, rather than a figure to hit exactly.
A level far from your real routine is the most common reason an estimate looks wrong. If you leave the field at whatever it opens on, the number may describe someone else's week rather than yours.
When your routine changes
Activity level is the input most likely to move. A new job, an injury, a busy month or a quieter one all change it. Run the calculator again once your routine has settled into something different, and the estimate moves with it.
What else changes the estimate
Age, assigned sex, height and weight each move the number too. Each one has its own article in the Academy if you want to know what it is doing.