Western Digital · NAS
WD181KFGX
WD Red Pro 18TB
SATA 6Gb/s · 3.5-inch · CMR
Exact Amazon US product
$544.00
View on Amazon US ↗Used / renewed listing · ASIN B09CN2CBH8
Price as of Sep 12, 2026 10:56 UTC
The Western Digital WD181KFGX is a 18TB WD Red Pro hard drive for NAS storage, using SATA 6Gb/s in a 3.5-inch form factor.
Manufacturer specifications
| Model number | WD181KFGX |
|---|---|
| Nominal capacity | 18 TB · 18000 GB |
| RPM | 7200 |
| Interface | SATA 6Gb/s |
| Recording | CMR |
| Cache (MB) | 512 |
| Form factor | 3.5-inch |
| Workload rating (TB/year) | 550 |
| Physical sector size (bytes) | 4096 |
| Manufacturer limited warranty | 5 years (eligible new drives) |
| Sustained transfer (up to MB/s) | 272 |
Source: Western Digital WD Red Pro manufacturer datasheet. Reviewed 2026-08-21. Published specifications, not our benchmark results.
What the specifications mean
- CMR recording is specified for this exact model. Check enclosure support and workload limits before installing it in an array.
- Up to 272 MB/s sustained transfer, as specified by the manufacturer. This is not a measured game-loading or random-I/O result.
- 550 TB/year workload rating. This is a workload limit, not a promise of drive lifespan or a backup guarantee.
Before ordering
Match WD181KFGX, 18TB and SATA 6Gb/s against the selected offer. Check your system’s exact-model compatibility list and the seller’s warranty and return terms.
Amazon US listings
Exact model matches on Amazon.com. A verified ASIN identifies the product; it does not guarantee current stock. Check the selected variant, condition and seller.
Amazon US · ASIN B09CN2CBH8
$544.00 · as of Sep 12, 2026 10:56 UTC
Amazon US · ASIN B08QVFKGQR
$697.00 · as of Sep 12, 2026 10:56 UTC
Same-capacity alternatives with Amazon US links
These models share the drive type, interface class and capacity. Compare their specifications and your system requirements before choosing a replacement.
Seagate · IronWolf Pro
ST18000NE000
18TB · SATA 6 Gb/s · CMR
Compare with WD181KFGX →View on Amazon US ↗ASIN B0CZM957F3 · Check price and conditionToshiba · MG09
MG09ACA18TE
18TB · SATA 6 Gb/s
Compare with WD181KFGX →View on Amazon US ↗ASIN B093Z5LFWD · Check price and conditionSeagate · Exos X18
ST18000NM000J
18TB · SATA 6 Gb/s
Compare with WD181KFGX →View on Amazon US ↗ASIN B08JV6PP9B · Check price and conditionWD181KFGX questions answered
Is WD181KFGX CMR or SMR?
The manufacturer lists CMR recording for WD181KFGX. Other models and capacities in the same family can differ.
What connection does WD181KFGX need?
WD181KFGX uses SATA 6Gb/s and a 3.5-inch form factor. Match both with the computer, controller or enclosure. An M.2 slot, 2.5-inch bay and 3.5-inch bay are not interchangeable.
How much usable space does WD181KFGX provide?
Its nominal capacity is 18000 GB, approximately 16763.8 GiB before formatting. The filesystem, reserved space and any RAID redundancy reduce usable capacity further.
What warranty is listed for WD181KFGX?
Manufacturer specification: 5 years (eligible new drives). A renewed, used, OEM or imported offer can have different coverage. Check the serial number and seller terms before buying.