US 4x 16TB RAID-Z1 NAS Calculator

Estimate usable TB, parity, and fault tolerance for US homelab buyers using 4x 16TB in RAID-Z1.

Capacity Snapshot

Raw Capacity

64.00 TB

Usable Capacity

43.20 TB

Fault Tolerance

1 drive

Efficiency

75.0%

ZFS single-parity equivalent of RAID 5; common for smaller homelab pools. This scenario applies a 10% filesystem reserve.

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Alternative Mode Comparison

Mode	Usable	Tolerance	Efficiency
RAID 5	43.20 TB	1 drive	75.0%
RAID 6	28.80 TB	2 drives	50.0%
RAID 10	28.80 TB	1 drive per mirror pair*	50.0%
RAID-Z1	43.20 TB	1 drive	75.0%
RAID-Z2	28.80 TB	2 drives	50.0%

US Buyer Context

US buyers often evaluate frequent pricing swings and promo cycles. Capacity planning should account for staged purchases instead of one-time all-disk upgrades.

• Use parity layouts that remain valid during phased expansions.
• Compare total usable-per-dollar across multiple disk sizes, not only one SKU.

Brand / Region Glossary

Cost-per-Usable-TB

Planning metric that compares real usable capacity after reserve and parity.

Promo Window

Seasonal pricing period used for phased drive purchasing strategies.

NAS Cluster Guides

NAS Hub RAID Level Compare RAID Capacity Matrix Planning Quick Sheet RAID Selector NAS FAQ

Related Long-Tail Calculators

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Sequential Long-Tail Navigation

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FAQ

How much real-world usable storage does 4x 16TB RAID-Z1 provide?

For US homelab buyers, this NAS planning scenario estimates 43.20 TB usable after a 10% reserve from 64.00 TB raw.

How many disk failures can RAID-Z1 tolerate in this setup?

This setup can tolerate 1 drive. Real-world survivability depends on mirror placement, rebuild stress, and drive health.

Why include a 10% reserve when planning NAS storage headroom?

Keeping free space improves filesystem behavior for snapshots, metadata, and write performance. Full arrays often perform worse and rebuild more slowly.

Can this calculator replace real-world benchmark and rebuild testing?

No. Use this page for pre-purchase sizing, then validate with workload benchmarks, SMART health policy, and a tested restore plan.