Variable width error correction is described. A memory controller can determine, from a memory address, what type of error correction is to be applied for the address region of that memory address and can generate commands for the memory device. An amount of error correction metadata associated with that address region may vary depending on the spatial location of the address region. In some cases, two translations may be performed: one by a processor using information set up by an operating system and another by the memory controller (or the memory device). In other cases, a single translation may be performed, for example by a processor using information set up by the operating system, which can determine the variable error correction during translation of a virtual address region to a real physical address region.