What is the minimum floor clearance for a bookcase that will be moved frequently?

Bookcases on casters need at least 3–4 in. of total frame-to-floor clearance for the caster wheel plus housing. Fixed-leg bookcases intended for frequent relocation should have leveling glides with at least 1/2 in. clearance to prevent the base panel from dragging. OfficeFurniture2go.com can specify the right casters or glides — call 1-800-460-0858.