Quick Answer+
Quick Answer: The Seagate IronWolf 18TB is the maximum capacity available in the standard IronWolf lineup—for larger sizes (20TB+), you must step up to IronWolf Pro. Standard IronWolf 18TB (~$330, ~$18.33/TB) delivers massive storage for home NAS users wanting top-tier capacity. IronWolf Pro 18TB (~$400, ~$22.22/TB) adds 5-year warranty and business features. Both use CMR technology and are ideal for data hoarders, large Plex libraries, and 4-6 bay builds where maximizing storage per bay is critical.
The 18TB capacity represents the ceiling of Seagate’s standard IronWolf lineup. If you need more than 18TB per drive and want to stay in the IronWolf family, you’ll need to upgrade to IronWolf Pro (which goes up to 24TB). This makes the 18TB an important decision point: maximize standard IronWolf or step up to Pro?
This guide covers both the standard IronWolf 18TB and IronWolf Pro 18TB, helping you understand when each makes sense and how they compare to neighboring capacities like 16TB and the Pro-exclusive 20TB+.
IronWolf 18TB Quick Specs
| Specification | IronWolf 18TB | IronWolf Pro 18TB |
|---|---|---|
| Model Number | ST18000VN003 | ST18000NT001 |
| Capacity | 18TB | 18TB |
| Interface | SATA 6Gb/s | SATA 6Gb/s |
| RPM | 7,200 | 7,200 |
| Cache | 256MB | 256MB |
| Workload Rating | 180 TB/year | 300 TB/year |
| MTBF | 1,000,000 hours | 1,200,000 hours |
| Warranty | 3 years | 5 years |
| Rescue Service | Optional add-on | Included (3 years) |
| Max Bays | 1-8 | 1-24 |
| Recording | CMR | CMR |
| RV Sensors | Yes | Yes (enhanced) |
| IronWolf Health Mgmt | Yes | Yes |
| Power (Idle/Active) | 5.3W / 8.0W | 5.3W / 8.0W |
| Noise (Idle/Seek) | 20dB / 30dB | 20dB / 30dB |
| Price | ~$330 | ~$400 |
| $/TB | ~$18.33 | ~$22.22 |
Current IronWolf 18TB Pricing
Live pricing comparison for 18TB IronWolf variants:
| Product | Capacity | Price | $ / TB | Price Drop | Brand | Interface |
|---|
Why 18TB Matters: The Standard IronWolf Ceiling
The 18TB capacity is strategically important in the IronWolf lineup:
- Maximum standard capacity: Largest drive available without stepping up to Pro
- Decision point: Need more? Must upgrade to IronWolf Pro (20TB, 22TB, 24TB)
- Cost efficiency: ~$18.33/TB is competitive with 16TB (~$18.13/TB)
- Bay maximization: Get more storage before adding more drives
Key question: If you need 18TB per drive but think you might eventually need more, consider whether starting with IronWolf Pro makes sense for the upgrade path to 20TB+.
IronWolf 18TB vs IronWolf Pro 18TB
Choose Standard IronWolf 18TB If:
- Home NAS use: Plex, file storage, personal backups
- 1-8 bay systems: Standard home/prosumer NAS configurations
- Workload under 180TB/year: Typical home use is well under this
- Budget priority: Save ~$70 per drive ($280 on 4 drives)
- 18TB is your ceiling: You won’t need 20TB+ per drive
Seagate IronWolf 18TB
18TB | 7200 RPM | 256MB Cache | CMR | 180TB/yr | 3-Year Warranty
The largest capacity available in standard IronWolf. Maximum storage for home NAS builds without the Pro premium. Perfect for data hoarders, massive Plex libraries, and users who want every terabyte per bay.
Choose IronWolf Pro 18TB If:
- Business/professional use: Where 5-year warranty matters
- 8+ bay systems: Enhanced RV sensors for large arrays
- Heavy workloads: Video editing, databases, busy file servers
- Future upgrade path: May need 20TB+ drives later
- Want Rescue service: Included data recovery insurance
Seagate IronWolf Pro 18TB
18TB | 7200 RPM | 256MB Cache | CMR | 300TB/yr | 5-Year Warranty | Rescue Included
High-capacity Pro with all business-grade features. 5-year warranty and Rescue service included. Choose this if you need the upgrade path to 20TB+ or run demanding workloads. Best for 6+ bay business NAS.
For detailed comparison, see: IronWolf vs IronWolf Pro Complete Guide
18TB Capacity Calculations
What Can You Store on 18TB?
- 4K Movies: ~360 films (50GB average)
- 1080p Movies: ~1,800 films (10GB average)
- RAW Photos: ~720,000 images (25MB average)
- FLAC Music: ~360,000 songs (50MB average)
- PC Backups: ~36 complete system backups (500GB each)
- Video Projects: ~180 hours of 4K ProRes footage
RAID Usable Capacity with 18TB Drives
Using our RAID Calculator:
| Configuration | Raw Capacity | RAID Type | Usable Capacity | Protection |
|---|---|---|---|---|
| 2x 18TB | 36TB | RAID 1 / SHR | ~16.4TB | 1 drive |
| 4x 18TB | 72TB | RAID 5 / SHR | ~49TB | 1 drive |
| 4x 18TB | 72TB | RAID 6 / SHR-2 | ~32.7TB | 2 drives |
| 6x 18TB | 108TB | RAID 5 / SHR | ~81.8TB | 1 drive |
| 6x 18TB | 108TB | RAID 6 / SHR-2 | ~65.4TB | 2 drives |
| 8x 18TB | 144TB | RAID 6 / SHR-2 | ~98TB | 2 drives |
Notable: 4x 18TB in RAID 5 gives ~49TB usable—nearly 50TB of protected storage in just 4 bays.
For RAID planning: Synology RAID Guide | SHR Explained | SHR vs RAID 5
18TB vs Other Capacities
18TB vs 16TB
| Factor | 16TB IronWolf | 18TB IronWolf | Winner |
|---|---|---|---|
| Price | ~$290 | ~$330 | 16TB cheaper |
| $/TB | ~$18.13 | ~$18.33 | 16TB (marginal) |
| 4-drive raw capacity | 64TB | 72TB | 18TB (+12.5%) |
| 4-drive usable (RAID 5) | ~43.5TB | ~49TB | 18TB (+12.5%) |
| Availability | Excellent | Good | 16TB |
Verdict: Very close in $/TB. Choose 18TB if you want maximum capacity per bay and the extra ~$40/drive is acceptable. Choose 16TB for slightly better value and availability.
18TB vs 20TB (Pro Only)
| Factor | 18TB Standard | 18TB Pro | 20TB Pro |
|---|---|---|---|
| Price | ~$330 | ~$400 | ~$450 |
| $/TB | ~$18.33 | ~$22.22 | ~$22.50 |
| Warranty | 3 years | 5 years | 5 years |
| Workload | 180TB/yr | 300TB/yr | 300TB/yr |
| Rescue | No | Yes | Yes |
Verdict: If you’re considering Pro 18TB (~$400), the 20TB Pro (~$450) offers better $/TB at the same warranty/features. The standard 18TB remains the best value for home users not needing Pro features.
18TB vs 12TB
| Factor | 12TB IronWolf | 18TB IronWolf | Winner |
|---|---|---|---|
| Price | ~$210 | ~$330 | 12TB cheaper |
| $/TB | ~$17.50 | ~$18.33 | 12TB |
| 4-drive raw capacity | 48TB | 72TB | 18TB (+50%) |
| Total cost (4 drives) | ~$840 | ~$1,320 | 12TB (-$480) |
Verdict:12TB offers better $/TB but 18TB provides 50% more capacity per bay. If you have limited bays (2-4) and need maximum storage, 18TB is worth the premium. If you have more bays available, 12TB offers better economics.
Best NAS Systems for 18TB Drives
2-Bay NAS with 18TB Drives
Configuration: 2x 18TB = 36TB raw, ~16.4TB usable (RAID 1)
- Synology DS224+ — Best 2-bay with Intel transcoding
- QNAP TS-253E — 2.5GbE, Intel N5105
Note: For 2-bay, consider if 18TB is necessary—you might get better value with 12TB or 16TB drives.
4-Bay NAS with 18TB Drives
Configuration: 4x 18TB = 72TB raw, ~49TB usable (SHR/RAID 5)
- Synology DS423+ — Best value 4-bay
- Synology DS923+ — Business 4-bay, expandable to 9
- QNAP TS-464 — Intel, dual 2.5GbE
This is the sweet spot for 18TB drives—nearly 50TB usable in a compact 4-bay form factor.
6-8 Bay NAS with 18TB Drives
Configuration: 6x 18TB Pro = 108TB raw, ~82TB usable (SHR/RAID 5)
Note: For 6+ bays, consider IronWolf Pro for enhanced vibration handling
- Synology DS1621+ — 6-bay, expandable to 16
- Synology DS1821+ — 8-bay powerhouse
- QNAP TS-873A — AMD Ryzen, 8 bays
18TB IronWolf vs Competitors
| Drive | Price | $/TB | Workload | Warranty | Notes |
|---|---|---|---|---|---|
| IronWolf 18TB | ~$330 | $18.33 | 180TB/yr | 3 years | Max standard capacity |
| IronWolf Pro 18TB | ~$400 | $22.22 | 300TB/yr | 5 years | Rescue included |
| WD Red Plus 18TB | ~$350 | $19.44 | 180TB/yr | 3 years | No 18TB in Plus |
| WD Red Pro 18TB | ~$420 | $23.33 | 300TB/yr | 5 years | No Rescue |
| Exos X18 18TB | ~$300 | $16.67 | 550TB/yr | 5 years | Best value, louder |
| Toshiba N300 18TB | ~$340 | $18.89 | 180TB/yr | 3 years | Solid alternative |
Key insights:
- Best overall value:Exos X18 18TB at ~$16.67/TB if noise isn’t a concern
- Best NAS-specific: IronWolf 18TB for IHM and quieter operation
- WD alternative: Red Pro 18TB exists but is pricier without Rescue
Detailed comparisons: IronWolf vs WD Red | IronWolf vs Exos
Use Case Recommendations
🎬 Large Plex Library
Recommended: Standard IronWolf 18TB
For massive 4K movie collections where capacity is the priority:
- 4x 18TB in DS923+ = ~49TB usable
- Enough for ~1,000 4K movies with room to grow
📦 Serious Data Hoarding
Recommended: IronWolf 18TB or Exos 18TB
For Linux ISOs, archives, and collections:
- Consider Exos 18TB for better $/TB if noise is acceptable
- IronWolf 18TB if you want quieter operation and IHM
💼 Business File Server
Recommended: IronWolf Pro 18TB or 20TB
If you’re going Pro for business, consider:
- Pro 18TB at ~$400 vs Pro 20TB at ~$450
- 20TB offers better $/TB with same features
- Or Pro 16TB at ~$350 for best Pro value
🎬 Video Production Archive
Recommended: IronWolf Pro 18TB or 20TB
Video archives need capacity and reliability:
- Pro for 300TB/year workload during active projects
- 5-year warranty protects valuable footage
Compatibility
Synology Compatibility
IronWolf 18TB is on Synology’s official compatibility list with full IronWolf Health Management support. Compatible with all current DiskStation and RackStation models.
See: IronWolf Synology Compatibility | All Synology Compatible Drives
QNAP Compatibility
Full compatibility with all QNAP NAS models. IHM supported in QTS.
See: IronWolf QNAP Compatibility
Other NAS Brands
Works with ASUSTOR, TerraMaster, Drobo, and other brands. IHM support varies.
Frequently Asked Questions
Yes, 18TB is the maximum capacity in the standard IronWolf lineup. For larger capacities (20TB, 22TB, 24TB), you must upgrade to IronWolf Pro. This makes 18TB an important decision point—if you might need more per drive later, consider starting with Pro.
Very close decision. 18TB costs ~$40 more but provides 12.5% more capacity. If you have limited bays and want maximum storage, 18TB is worth it. If budget is priority and you have room for more drives later, 16TB offers marginally better $/TB. Both are excellent choices.
Yes, the IronWolf 18TB is a reliable NAS drive. It uses CMR recording (not SMR), includes rotational vibration sensors, and supports IronWolf Health Management. Rated for 1 million hours MTBF and 180TB/year workload. Backed by 3-year warranty (5-year for Pro).
Exos 18TB offers better value: lower price (~$300 vs $330), higher workload (550TB/yr), and 5-year warranty. IronWolf 18TB is quieter and includes IronWolf Health Management. Choose Exos for closet/basement NAS; IronWolf for living space or if you want IHM features.
If you’ve decided on Pro, the 20TB offers better $/TB (~$22.50 vs ~$22.22) at only $50 more. You get 2TB extra capacity with the same 5-year warranty and Rescue service. Unless 18TB is exactly what you need, 20TB Pro is the better Pro choice at this tier.
Depends on your capacity needs and RAID level. For reference: 2x 18TB (RAID 1) = ~16TB usable, 4x 18TB (RAID 5) = ~49TB usable, 6x 18TB (RAID 5) = ~82TB usable. Use our RAID Calculator to plan your specific configuration.
Conclusion
The Seagate IronWolf 18TB is the maximum capacity available in the standard IronWolf lineup—perfect for users who want top-tier storage without stepping up to Pro pricing. The standard 18TB offers excellent value for home NAS users with massive storage needs.
Quick recommendations:
- Home users wanting max capacity: Standard IronWolf 18TB
- Business/may need 20TB+ later: IronWolf Pro 18TB or 20TB
- Maximum value (noise OK):Exos X18 18TB
- Slightly better $/TB:IronWolf 16TB
Related Resources
- Seagate IronWolf Complete Guide
- Seagate IronWolf Pro Guide
- IronWolf vs IronWolf Pro
- IronWolf 16TB Guide
- IronWolf 12TB Guide
- IronWolf vs Exos
- Synology Compatible Drives
- RAID Calculator
Last Updated: February 2026