Aspects of the present disclosure relate to storage policy change usage estimation. In examples, a base storage utilization is generated for a storage object according to a current storage policy. The current storage policy may comprise a RAID (“redundant array of independent disks”) level and/or a fault tolerance level with which the storage object is stored. An estimated storage utilization may then be generated for the storage object based on the base storage utilization and a new storage policy accordingly. Thus, the base storage utilization may omit or otherwise account for overhead associated with the RAID level and/or fault tolerance level indicated by the current storage policy, while the resulting estimated storage utilization may indicate an estimated physical storage utilization for the storage object if the new storage policy is implemented in place of the current storage policy.