homelab

Calculate usable ZFS pool capacity for any RAID level including stripe, mirror, raidz1, raidz2, and raidz3. Computes raw capacity, parity overhead, data disk count, usable terabytes after ZFS metadata overhead (checksums, block pointers, uberblocks), and storage efficiency percentage. Essential for planning NAS builds, TrueNAS/ZFS server storage, and estimating how much usable space a given disk configuration will provide. Supports variable disk sizes and configurable metadata overhead.

post/api/zfs_capacity

Request

  • Base URL: https://calc.engineer
  • URL: https://calc.engineer/api/zfs_capacity
  • Auth: none declared

Request body

disk_countnumber required

Total number of physical disks in the pool

disk_size_tbnumber required

Size of each individual disk in terabytes

raid_type'stripe' | 'mirror' | 'raidz1' | 'raidz2' | 'raidz3'

ZFS RAID level: stripe (no redundancy), mirror (2-way), raidz1/2/3 (single/double/triple parity)

record_size_kbnumber

ZFS record size in kilobytes, affects compression and performance

metadata_overhead_pctnumber

Percentage of raw capacity consumed by ZFS metadata, checksums, and internal structures

Response

Computed result for zfs_capacity

toolstring required
versionstring required
computed_atstring date-time required

Changes

No recorded changes to this operation across all 1 revision of this API.