A compact refrigerator can fit inside the measured opening and still be unsafe or frustrating to use. The real footprint includes manufacturer-required ventilation, the power connection, and enough room to open the door and remove shelves.
Use the model's clearance instructions
There is no single universal gap that works for every mini fridge. Read the exact manual for required space at the sides, rear, and top, then add those clearances to the listed exterior dimensions. Freestanding refrigerators should not be treated as built-in appliances unless the manufacturer specifically approves an enclosed installation.
Measure the door in its open position
Check which side the door hinges from, whether it is reversible, and how far it must open for bins, shelves, or drawers to come out. A door beside a wall may open enough to reach a drink but not enough to remove a crisper or clean the interior. Include any handle, hinge cap, and door edge that extends beyond the cabinet.
Plan the plug and delivery path
Measure the outlet position and plug depth without crushing the cord behind the refrigerator. Then check doors, stairs, elevators, hallway turns, counter edges, and the final opening. Use the packaged dimensions when available because protective material can make delivery wider than the bare appliance.
Account for heat and room conditions
A refrigerator moves heat from inside the cabinet into the surrounding room. Tight alcoves, direct sun, nearby cooking appliances, garages, and rooms outside the permitted ambient-temperature range can affect operation. Follow the manual's placement limits and keep ventilation openings clear rather than using the top or sides as packed storage.
Compare usable storage, not height alone
Very short models save vertical space but may sacrifice shelving, freezer room, or bottle storage. Taller compact refrigerators can hold more food while staying narrow. After eliminating models that fail the clearance and door tests, compare shelf layout, freezer configuration, defrost method, noise considerations, and the foods the household actually stores.