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.
Prices updated hourly from Amazon US and UK. All links go directly to the retailer. Details.
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.
MDD MAXDIGITALDATA MDD 18TB 7200RPM 256MB Cache SAS 12.0Gb/s 3.5inch Internal Enterprise Hard Drive (MDD18TSAS25672E) - [Not a SATA HDD]
WD 18TB Elements Desktop External Hard Drive - USB 3.0, Black
Western Digital WD WUH721818AL5204 18TB SAS 12Gb/s 7.2K RPM 512M 0F38353 512e/4Kn SE HDD
Avolusion PRO-G2 18TB USB 3.2 Gen 2 (10Gbps) External Hard Drive for Windows/MacOS (Silver)
WD Elements 18TB Desktop USB 3.0 External Hard Drive with the SanDisk Ultra 256GB USB 3.0 Flash Drive
Western Digital DC HC550 18TB 512MB SATA Ultra SE NP3
MG09SCA18TE 18TB Toshiba SAS 12 Gb/s 512MB 3.5 Inch 7200 RPM Enterprise HDD for Dell HP Lenovo Supermicro Server Hard Drive
WD HGST - Single 18TB 3.5IN 26.1MM 512MB 7200RPM SAS Ultra 512
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 Enterprise Hard Drive 18TB (3.5" SATA 6Gbps, SAS 12Gbps, 7200RPM, 512MB Cache)
Seagate Exos X18 Enterprise Class, 18TB, Enterprise Internal Hard Drive, SATA, 3,5" 6Gbit/s, 128MB cache ((ST18000NM000J)
Western Digital Ultrastar DC HC550 18 TB Hard Drive - 3.5" Internal - SATA
Seagate Exos X18 ST18000NM005J 18 TB Hard Drive - Internal - SAS (12Gb/s SAS) - 7200rpm - 5 Year Warranty
Seagate ST18000NM003D 18TB Exos X20 SATA Hard Drive, 3.5" HDD, SATA 6Gb/s, 7200rpm, 256MB Cache, 512E, 4.16ms, NCQ
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.
Seagate IronWolf Pro 3.5-inch 18TB Internal Hard Disk HDD CMR 3.5 Inch Data Recovery ST18000NT001 6Gb/s 256MB 7200 rpm 24 Hour Operation PC
Seagate IronWolf Pro 18TB ST18000NE000 internal hard drive 3.5" 18000 GB Serial ATA III
WD Red Pro 18TB NAS 3.5" Internal Hard Drive - 7200 RPM Class, SATA 6 Gb/s, CMR Recording Technology, 512MB Cache
WD Red Pro 18TB NAS 3.5" Internal Hard Drive - 7200 RPM Class, SATA 6 Gb/s, CMR, 512MB Cache
WESTERN DI - WD Red PRO Nas Hard Drive WD181KFGX - HD - 6176921
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.
MDD MAXDIGITALDATA X18 MACH.2 (Dual Actuator) 18TB 7200RPM SAS 12Gb/s 512MB Cache 3.5-Inch Enterprise Hard Drive (MDD18TSAS51272E-2X18) - [Not a SATA HDD] (Renewed)
Western Digital HDD Gold 18 TB SATA 512 MB 3.5 Inch
WD 18TB Elements Desktop External Hard Drive - USB 3.0, Black
Western Digital WD WUH721818AL5204 18TB SAS 12Gb/s 7.2K RPM 512M 0F38353 512e/4Kn SE HDD
Water Panther 18TB SAS 12Gb/s 7.2K RPM 3.5-Inch Enterprise Hard Disk Drive in 14G 15G Tray Compatible with Dell PowerEdge Servers R240 R340 R740XD R550 R750 (Renewed)
Water Panther 18TB 7200 RPM SAS 12Gb/s 3.5-Inch Enterprise Hard Disk Drive in 13G Tray Compatible with Dell PowerEdge Servers R730XD R730 T340 T330 T640 T630 T440 (Renewed)
Water Panther WP Arsenal 18TB SAS 12Gb/s 7200RPM 3.5-Inch DAS Hard Drive for Storage Server, Enterprise JBOD, Business RAID Workstation, Internal SAS LFF HDD (Renewed)
MDD (MDD18TSATA25672DVR) 18TB 7200RPM 256MB Cache SATA 6.0Gb/s 3.5-inch Internal Surveillance Hard Drive - 3 Years Warranty (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 US & UK — prices checked every hour so you never overpay.