Find the Cheapest 4TB NAS Drive Today
4TB NAS-rated CMR drives by price per TB
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The best 4TB NAS drives are NAS-rated CMR models. 4TB is an entry size, best for a 2-bay starter NAS doing backups, documents and a phone photo cloud rather than a large media library. Choose a CMR drive (WD Red Plus, Seagate IronWolf or Toshiba N300) and avoid SMR for a safe RAID rebuild. The live table ranks current 4TB drives by price per terabyte.
Who a 4TB NAS drive suits
4TB is an entry size, best for a 2-bay starter NAS doing backups, documents and a phone photo cloud rather than a large media library. It is the sensible first step if you are leaving Google Photos or iCloud and do not yet have terabytes of data.
4TB is light for Plex: a 4K film can be 40GB or more, so a 4TB pool fills quickly. It is fine for a modest library or as a starting point you grow later.
Where 4TB sits on the value curve
Small drives sit at the expensive end of the price-per-terabyte curve: a 4TB drive almost always costs more per terabyte than an 8TB to 12TB one. If your budget stretches, a single larger drive is usually better value, but 4TB keeps the upfront cost low for a first NAS.
At 4TB the value picks are WD Red Plus, Seagate IronWolf and Toshiba N300, which trade the lead on price per terabyte. The live table is sorted so the cheapest per terabyte is at the top.
Usable capacity from 4TB drives
| Use case | Best choice | Why |
|---|---|---|
| 2x 4TB, RAID 1 / SHR | ~4TB usable | A mirror: survives one drive failure, half the raw capacity. |
| 4x 4TB, RAID 5 / SHR | ~11TB usable | Single parity: survives one failure, about 75% of raw. |
| 4x 4TB, RAID 6 / SHR-2 | ~7TB usable | Dual parity: survives two failures, the safer choice at high capacity. |
The 4TB buying note
The main trap at 4TB is buying an SMR drive by mistake. This is exactly the capacity band where the old WD Red (EFAX) shingled models live, and cheap desktop drives are often SMR too. Stick to WD Red Plus, IronWolf or N300, which are all CMR, so a RAID rebuild stays fast and safe.
Available NAS-rated families at 4TB: At 4TB you have WD Red Plus, Seagate IronWolf and Toshiba N300, the mainstream NAS-rated CMR drives. Enterprise Exos and the Pro ranges exist at this size but rarely make sense here, as their value only shows at higher capacities.
4TB NAS drives, by price per TB
Renewed, refurbished and used listings
Shown for reference. These are not counted in the best price per TB above, and warranty terms differ from new drives.
Frequently asked questions
How many 4TB drives do I need for around 11TB usable?
Four 4TB drives in RAID 5 or Synology SHR give about 11TB usable after parity and overhead, with single-drive fault tolerance. Two 4TB drives in a mirror give about 4TB. For two-drive protection, four in RAID 6 or SHR-2 give about 7TB.
Is 4TB enough for a home NAS?
For backups, documents and a phone photo cloud, 4TB in a 2-bay NAS is enough to start. For a growing Plex or RAW photo library, step up to the 8TB to 12TB value tier so you are not upgrading again within a year.
What is the cheapest 4TB NAS drive?
At 4TB the value picks are WD Red Plus, Seagate IronWolf and Toshiba N300, which trade the lead on price per terabyte. The live table is sorted so the cheapest per terabyte is at the top.
Does a 4TB drive need RAID 6 instead of RAID 5?
Not necessarily at 4TB. RAID 5 or SHR rebuilds quickly enough at this size for most home use. RAID 6 or SHR-2 adds a safety margin if the data is irreplaceable, at the cost of one more drive of capacity.