The floor is the most expensive storage in a garage, and the ceiling is the cheapest. A 4x8 overhead rack recovers about 32 square feet you already paid for. The only question that matters before you buy one is what the ceiling can carry.
Find the structure first, not the drywall
An overhead rack is only as strong as what it is bolted into. Lag bolts must land in ceiling joists or roof trusses — never drywall anchors, and never the sheathing alone. Run a stud finder across the ceiling and mark the centers; in most homes they sit 16 or 24 inches apart. If your marks do not line up at a consistent spacing, stop and check again. Guessing here is how racks come down.
Trusses are engineered as a system. Bolting into the bottom chord of a truss near a joint is generally fine for storage loads; hanging heavy weight in the middle of a long unsupported span is not. If your garage has a finished room above it, you are dealing with floor joists rather than trusses, and those have more capacity to spare.
Read the load rating the way the manufacturer meant it
A rack advertised at 600 lbs means 600 lbs evenly distributed across the whole deck when it is installed exactly as specified — correct bolts, correct joist spacing, all four uprights carrying weight. It does not mean you can stack 600 lbs in one corner. As a working habit, load the heavy things toward the uprights and keep the middle of the deck for light, bulky items: holiday bins, camping gear, empty coolers.
Then leave yourself margin. Loading to about half the rated capacity costs you nothing and covers the small sins every real installation has — a bolt that caught the edge of a joist, a span an inch longer than the instructions assumed.
Height is a safety feature
Most overhead racks adjust between roughly 22 and 45 inches of drop. People tend to hang them as high as possible and then find they cannot reach the load without a ladder and both hands. Measure your garage door in its open position before you commit — the door and its track are the real ceiling. Then set the rack so the bins clear the door by a few inches and no more.
What belongs up there, and what does not
Overhead is for things you touch once or twice a year, in containers that will not spill if they are bumped: seasonal decorations, luggage, sports gear, spare bedding. Keep anything liquid, anything you need weekly, and anything genuinely heavy — tools, paint, batteries — down at bench height where you can see it and lift it safely.
If you are working out where things go, start with what goes up: browse overhead racks and wall systems, then work down to shelving that carries weight.