"Moderately active" is where most calorie estimates go wrong. Instead of picking a vague label, lay out your actual 24 hours — sleep, desk work, walking, training — and get a TDEE built from your real schedule. It has to add up to a full day, which is itself harder to fudge than a dropdown.
One MET is roughly the energy you burn at rest — about 1 calorie per kilogram of body weight per hour. Every activity has a MET value: sleeping is about 0.95, desk work around 1.5, brisk walking around 3.3, hard cardio 8 or more. Your day's calories are simply each block's MET value times your weight times its hours, added up.
Because sleep and rest sit near 1 MET — close to your basal rate — a full 24-hour timeline naturally rebuilds your total daily expenditure as "resting plus everything you did," without double-counting. The tool also shows the equivalent activity multiplier (your day ÷ your BMR) so you can see where your real schedule lands against the usual labels — and flags it if the result is implausibly high, which usually means an activity's intensity or hours were overestimated.
It pairs with the rest of the site: take the calorie figure into the planner to build a goal schedule, or read how to choose an activity level for why the dropdown trips so many people up.