Find out how long your NAS storage will last based on your real data growth rate. Get a year-by-year projection, see when you'll need to upgrade, and find the cheapest expansion path.
This NAS storage capacity growth planner projects how long your current NAS will last based on total capacity, current usage, and your annual data growth rate. Outputs a year-by-year forecast showing when you'll hit capacity limits and compares drive expansion versus full NAS upgrade costs.
Most households that deploy a NAS for photos, video, and backups start with 4 to 8 TB and fill it within 3 to 5 years. The biggest growth drivers are 4K video (a single hour of HEVC footage runs 15 to 25 GB), RAW photo libraries from modern mirrorless cameras (35 to 80 MB per shot), and game libraries synced locally. Business NAS systems grow faster: financial records, scanned documents, and project archives compound year over year without natural cleanup cycles.
Annual growth rates vary widely by user type. Photo and video hobbyists typically see 500 GB to 1.5 TB growth per year. Households running automated phone backups across multiple family members often hit 1 to 2 TB annually. Small video production setups can exceed 4 TB per year. This planner lets you enter your real growth rate and projects exactly when your current setup will hit its ceiling.
The most common NAS mistake is choosing a 2-bay unit to save $200, then needing a full replacement within 2 to 3 years when it fills up. A 2-bay NAS running RAID 1 can only ever hold two drives. When you're full, the only option is to replace the entire unit. A 4-bay NAS running RAID 5 can expand one drive at a time, swapping each drive for a larger capacity across multiple upgrade cycles. The price difference between a 2-bay and 4-bay entry-level NAS is typically $200 to $300 AUD. If you replace your 2-bay after two years, you spend that $200 to $300 again on a new unit, plus the time cost of migrating your data.
This planner outputs a year-by-year capacity forecast and compares the cost of staying with your current NAS (adding drives) versus upgrading to a larger enclosure. It accounts for RAID efficiency loss so the usable storage figures are realistic, not marketing numbers.
| Year | Data | % Full | Capacity | Status |
|---|
| User type | Typical starting data | Annual growth | Suggested minimum (5-year) |
|---|---|---|---|
| Family photos + docs | 500 GB – 2 TB | 150–200 GB/yr | 4 TB usable (2-bay RAID 1) |
| Photo + video enthusiast | 2–5 TB | 500 GB – 1 TB/yr | 12 TB usable (4-bay RAID 5) |
| Media collector (movies, music) | 5–20 TB | 1–3 TB/yr | 24 TB+ usable (4–6 bay) |
| Small business (5–10 staff) | 1–5 TB | 200–500 GB/yr | 8 TB usable (4-bay RAID 5) |
| Surveillance (4 cameras, 24/7) | 0 TB (fresh) | 2–4 TB/yr | 16 TB+ usable (4+ bay) |
| Homelab (VMs, Docker, AI) | 1–3 TB | 500 GB – 1 TB/yr | 12 TB usable minimum |
The most common NAS buying mistake: choosing a 2-bay to save $200, then needing a full replacement within 2 years. Here's why a 4-bay is usually the smarter investment.
A 2-bay NAS running RAID 1 gives you exactly half your drive capacity as usable storage, two 8TB drives gives you 8TB usable. There's no way to add more drives. The only way to expand is to replace the entire NAS enclosure.
A 4-bay NAS running RAID 5 gives you 75% efficiency, four 8TB drives gives you 24TB usable. When you need more space, you replace one drive at a time with a larger drive. A 2-to-4-bay upgrade requires buying a new NAS; a 4-to-6-bay expansion requires a new enclosure but not new drives in most cases.
The maths: the price difference between a 2-bay and 4-bay entry-level NAS is typically $200–300 AUD. If you need to upgrade your 2-bay after 2 years, you're spending that same $200–300 again on a new unit, plus migrating your data. The 4-bay pays for its premium up front.
The exception: if your data genuinely won't grow beyond what a 2-bay can handle for 5+ years, and you value the smaller footprint, a 2-bay is a legitimate choice. This planner helps you check that assumption with real numbers.
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