Track your body weight daily for 2 to 4 weeks
Keep your food intake consistent during the tracking period
Calculate your average daily calorie intake over the period
Compare your average weight at the start and end of the period
If weight stays stable, your average intake is your maintenance calories
If weight increases, reduce calories slightly and retest
If weight decreases, increase calories slightly and retest
Adjust by 100 to 200 calories at a time
Repeat the tracking process until weight remains stable
Use activity level, age, sex, height, and weight as a starting estimate if needed
Reassess maintenance calories after changes in activity, body weight, or training volume