Two sizes cover almost every shed
A shed comes down in a weekend: big enough to justify a dumpster, small enough to be done by Sunday night. The one real decision comes before the first swing: the size of the box.
Small shed: the 10 yard. The tool shed, the single-door garden shed: 3 to 4 pickup truck loads of debris, no more. The box is 14 ft by 8 on the ground and 2.5 ft high — a low wall you load at arm's height, nothing thrown over a shoulder.
Regular shed: the 20 yard. Same rectangle on the ground — 14 ft by 8 — but 5 ft high, for 6 to 8 pickup truck loads: about the size of a Dodge Caravan. It is the size the size guide recommends for tearing down a shed, and its margin absorbs the part everyone forgets: whatever is still stored inside comes down too. A large shed packed to the rafters, though, can tip into the 40 yard — the pickup-load count decides.
Between the two, one useful rule: dropping to the 10 yard frees no room in the driveway — the footprint is the same. You pick the 10 for the volume, never for the space.