NAS Drive Sizing Calculator
Calculate how much NAS storage you need based on users and growth.
Results
Planning a NAS purchase requires estimating not just current storage needs but future growth. Data volumes typically grow 20-40% per year for active users. Adding RAID overhead for redundancy means you need more raw capacity than your usable data. This calculator projects your storage needs and recommends drive configurations.
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Frequently asked questions
A typical household of 3 needs about 1.5 TB currently (500 GB each for photos, videos and documents). With 20% annual growth over 3 years, plan for about 2.6 TB usable - a 4-bay NAS with 4 TB drives in RAID 5 (12 TB usable) gives plenty of room.
Most households see 20-30% annual growth driven by higher resolution photos and videos. A family that uses 1 TB today will likely need 1.7 TB in 3 years and 3 TB in 5 years at 20% growth.
A minimum of 2 drives for RAID 1 (mirroring) or 3 drives for RAID 5. Most home NAS units have 2-4 bays. A 4-bay NAS with RAID 5 gives a good balance of capacity, redundancy and cost.
Fewer larger drives are usually better for home use. 4 x 8 TB drives give 24 TB raw (18 TB usable in RAID 5) with room to grow, are quieter and use less power than 8 x 4 TB drives for the same capacity.
RAID 5 for 3+ drive NAS units - it provides single drive failure protection with good capacity. RAID 1 for 2-drive NAS. Synology SHR (Synology Hybrid RAID) is a good choice for mixed drive sizes.