An hour of mowing the lawn doesn't come with a summary screen. No reps, no pace, no little graph at the end. It's just an hour of pushing, turning, and emptying a bag.
It's also one of the more substantial chunks of physical work in a lot of weeks, and it tends to vanish completely when people describe their activity level.
What the multiplier is actually adding up
TDEE is your basal metabolism times an activity factor. Basal metabolism covers roughly 60–70% of daily burn; the multiplier accounts for everything on top: walking, standing, stairs, chores, fidgeting, and yes, yard work.
Two people with the same desk job can differ by hundreds of calories a day in this category. The difference is rarely the gym. It's the unlogged part of the week.
Seasonal swings are real
In April and May there's mowing, planting, and bags of mulch. In January there's a shovel and a driveway, or nothing at all. A single activity label has to cover all of it, which is exactly why it's the least precise field in the calculator.
Don't change the setting after one big Saturday. If the pattern holds for a few weeks, that's a reasonable time to revisit it. Formulas already carry about 10–20% individual error, so a seasonal shift within that band isn't a mystery to solve.
Don't double count it
If you already picked an activity level that describes an active week, you don't get to add the mower's estimated burn back on top as extra food. That counts the same hour twice.
Treat the number on a tracker as a rough marker, not a refund. Two or three weeks of stable intake and a weekly weight average will tell you far more.
Give the ordinary work its due
Raking leaves, carrying grocery bags, wiping down the car, shoveling a walk — none of it looks like a workout, and all of it is part of the week you're trying to describe.
The estimate gets better when the description gets more honest. That's it.