Best 18 TB Hard Drives
18 TB is a popular capacity sweet spot for NAS builders, homelab enthusiasts, and small-business storage. It offers strong density per bay slot without the price premium of cutting-edge 20-24 TB models. At this capacity point, you will find mature, well-proven models from both Seagate and Western Digital across enterprise, NAS, and general-purpose lines.
Why 18 TB?
18 TB drives hit a practical balance: enough capacity to meaningfully reduce the number of bays needed, but typically priced lower per TB than 20 TB+ models because they use established platter technology. For a 4-bay NAS, four 18 TB drives give you 72 TB raw, or ~54 TB usable in RAID 5.
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Best Value 18 TB Drives
All new 18 TB hard drives ranked by price per terabyte. The best deals across enterprise, NAS, and standard lines.
Seagate Enterprise ST18000NM004J Internal Hard Drive 3.5" 18TB SAS
Western Digital 18TB WD Red Pro NAS Internal Hard Drive HDD - 7200 RPM, SATA 6 Gb/s, CMR, 512 MB Cache, 3.5" - WD181KFGX
Western Digital 18TB WD Gold Enterprise Class Internal Hard Drive - 7200 RPM Class, SATA 6 Gb/s, 512 MB Cache, 3.5" - WD181KRYZ
Western Digital Ultrastar DC HC550 18 TB Hard Drive - 3.5" Internal - SAS (12Gb/s SAS)
Western Digital DC HC550 18TB 512MB SATA Ultra SE NP3
Seagate EXOS X20 18TB SAS 3.5IN 7200RPM 6GB/S 512E/4K
Toshiba MG09ACA18TE 18 TB Hard Drive - 3.5 Internal - SATA [SATA/600]
Toshiba MG09 MG09SCA18TE 18 TB Hard Drive - Internal - SAS [3Gb/s SAS]
Enterprise 18 TB Drives
Seagate Exos and WD Ultrastar 18 TB models for server and datacenter use. 24/7 rated with 5-year warranties and high workload endurance.
Western Digital Ultrastar DC HC550 18 TB Hard Drive - 3.5" Internal - SAS (12Gb/s SAS)
Seagate EXOS X20 18TB SAS 3.5IN 7200RPM 6GB/S 512E/4K
Seagate ST18000NM003D 18TB Exos X20 SATA Hard Drive, 3.5" HDD, SATA 6Gb/s, 7200rpm, 256MB Cache, 512E, 4.16ms, NCQ
Seagate Exos X18 ST18000NM005J 18 TB Hard Drive - Internal - SAS (12Gb/s SAS) - 7200rpm - 5 Year Warranty
Western Digital Ultrastar DC HC550 18 TB Hard Drive - 3.5 Internal - SATA
Seagate Exos X18 ST18000NM001J 18 TB Hard Drive - Internal - SATA (SATA/600)
NAS 18 TB Drives
IronWolf and WD Red 18 TB models designed for always-on NAS enclosures. NAS firmware optimisations for RAID and multi-bay vibration.
Refurbished 18 TB Drives
Used and recertified 18 TB drives at reduced prices. Enterprise datacenter pulls that offer strong value for non-critical storage and homelab use.
Avolusion M5 Series 18TB USB 3.0 External Hard Drive for WindowsOS Desktop PC/Laptop (Renewed)
Avolusion PRO-5X Series 18TB USB 3.0 External Hard Drive for WindowsOS Desktop PC/Laptop (White) (Renewed)
Avolusion PRO-Z Series 18TB USB 3.0 External Hard Drive for WindowsOS Desktop PC/Laptop (White) (Renewed)
MDD MAXDIGITALDATA MDD 18TB 7200 RPM 256MB Cache SATA 6.0Gb/s 3.5-inch Internal NAS Hard Drive (Renewed)
Avolusion PRO-H1 18TB 7200RPM USB 3.2 Gen2 (10Gbps) External Hard Drive (for Windows or MacOS Desktop PC/Laptop) (Renewed)
Avolusion PRO-T5 Series USB 3.0 External Hard Drive for WindowsOS Desktop PC/Laptop (White) - 2 Year Warranty (18TB) (Renewed)
MDD MAXDIGITALDATA MDD (MDD18TS25672NAS) 18TB 7200 RPM 256MB Cache SATA 6.0Gb/s 3.5'' Internal NAS Hard Drive (Renewed)
Avolusion PRO-X Series USB 3.0 External Hard Drive for WindowsOS Desktop PC/Laptop (White) - 2 Year Warranty (18TB) (Renewed)
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Best HDD Deals Right Now
Live hard drive deals ranked by price per terabyte. New and refurbished HDDs on Amazon.com. Prices checked daily so you never overpay.