For the first time, CFD-DEM simulations of small-scale fluidized beds are quantitatively validated against large-scale experiments. Such validation is possible via the identification of a measurement independent of system size, namely defluidization. CFD-DEM inputs (particle properties and operating conditions) are measured directly. Sphericity is found to be critical, even for highly spherical particles. This size-independent method of validation is valuable since it allows for validation of CFD-DEM models without restrictions on system sizes or particle sizes. (c) 2015 American Institute of Chemical Engineers.