NAND / SSD Capacity Calculator
Calculate raw and usable NAND capacity from die density, dies, channels, planes, and over-provisioning.
Live
Input
Usable Capacity
230.64 GB
Raw Capacity
256.00 GB
Example input:
256 Gb × 8 dies → 256 GB raw, ~219 GB usable (7% OP, 3.125% spare)Results
Engineering Notes
GB vs GiB
NAND manufacturers specify density in Gb (gigabits) using decimal units (1 Gb = 10^9 bits). When converting to GB, use 8 bits per byte: 256 Gb = 32 GB. In binary units, this is ~29.8 GiB.
OP and Endurance
Higher over-provisioning improves write endurance and sustained write performance because the controller has more spare blocks for garbage collection. Enterprise SSDs often have 28%+ OP.
This tool is intended for engineering analysis and educational purposes. Values and interpretations should be validated against the applicable JEDEC, PCI-SIG, NVM Express, MIPI, vendor datasheet or other authoritative specification.