Your home screen has the Calories burned tile: what you actively burned today.
Two sources. Your watch, through Apple Health or Health Connect, and the workouts you logged in the app that your watch didn’t measure. A run from the app has a calculated burn. A logged activity gets an estimate based on its type and intensity, and a strength workout without an activity gets a general estimate; it says so when that’s the case.
Not counted twice. A workout in the app that coincides with a workout on your watch counts once.
Active, not total. What you burn at rest is already included in your nutrition goal. That’s why only the active burn is shown on the tile.
Counting it in your nutrition. Under Count activity towards your nutrition you choose whether a hard day gives you extra room in your nutrition goal: not at all, half, or fully. Half is the usual compromise. If you have a coach, their goal already assumes an ordinary day.
A better number. Without your weight, the estimate uses 70 kilos. Enter your weight for a better number.