Methods, apparatus, systems and articles of manufacture are disclosed to manage memory allocation. An example apparatus includes a memory detector to scan a platform for available memory. The example apparatus also includes a memory size checker to retrieve a virtual memory layout associated with the available memory devices associated with the platform and to determine whether virtual address boundaries of respective ones of a available memory device generate a virtual address gap therebetween. The example apparatus also includes a address assigner to reassign virtual addresses of at least one of the respective ones of the available memory devices to remove the virtual address gap.