EndLBA

EndLBA is the last logical block address allocated to a partition or storage region on a device that uses logical block addressing (LBA. It, together with the StartLBA, defines the extent of the partition along the disk.

In most partitioning schemes, EndLBA is stored as part of the partition entry. In the traditional MBR scheme, each primary partition entry includes a 32-bit Ending LBA value, which limits partitions to addressing up to about 2 TB with 512-byte sectors. In the GPT scheme, the Ending LBA is a 64-bit field in the partition entry, allowing much larger disks.

Block size considerations are important when interpreting EndLBA. The number of blocks in a partition is EndLBA - StartLBA + 1. The partition size in bytes equals that difference multiplied by the logical block size, typically 512 or 4096 bytes, depending on the device.

EndLBA is used by partitioning tools, disk imaging software, and boot managers to determine partition boundaries and to calculate sizes or copy ranges. Many tools display both StartLBA and EndLBA when presenting partition layouts. It is also relevant when resizing or cloning partitions; correct handling of EndLBA helps prevent overlaps and data loss.

Limitations and caveats include sensitivity to disk sector size, alignment, and the use of protective MBR or dynamic disk structures. On drives with 4K sectors, 512-byte emulation can affect the reported EndLBA values, so accurate interpretation may require awareness of the device’s physical and logical sector sizes.