NAS vs. Cloud Storage: The Real 5-Year Cost Math
Run the numbers over 5 years instead of one, and the NAS-vs-cloud question stops being about opinion and becomes about capacity. At 2TB, five years of a consumer cloud subscription lands around $500–$600 — close enough to a budget NAS's amortized hardware-plus-electricity cost that it's a genuine toss-up. At 10TB and 30TB, consumer cloud tiers mostly stop existing, pushing you to per-GB object storage that keeps billing forever and scales linearly with capacity, while a NAS's cost is front-loaded once, then nearly flat. The crossover isn't really about time horizon — it's about how many terabytes you actually store.
Methodology and assumptions, dated 2026-07-30: cloud prices below are published consumer-tier subscription rates as of July 2026 — check each provider's current pricing before deciding, since these change with promotions and repositioning. NAS hardware is described in qualitative price bands, never exact prices (Amazon's Operating Agreement restricts price display, and street prices shift constantly) — see how we evaluate. Drive cost-per-TB and electricity are general cost estimates, not product prices, and vary by brand, capacity, and your local electricity rate. Drive-failure odds use Backblaze's published annualized-failure-rate data, applied as a rough probability model, not a guarantee about any specific drive.
What do consumer cloud tiers actually cost right now?
Published consumer subscription rates, snapshot as of July 2026 — always verify current pricing before buying, since providers adjust these often:
| Service | Tier | Published rate | ≈ 5-year total |
|---|---|---|---|
| Google One (now bundled as "Google AI Pro") | 2TB | ~$9.99/mo or ~$99.99/yr at standard renewal (promo pricing has run as low as ~$4.17/mo) | ~$500/5yr at standard renewal |
| Dropbox Plus | 2TB | ~$9.99/mo billed annually (~$119.88/yr), ~$11.99/mo month-to-month | ~$600/5yr |
| iCloud+ | 2TB | ~$9.99/mo, monthly billing only | ~$600/5yr |
| Backblaze B2 (object storage, not a sync app) | per-GB | ~$6/TB/month (~$72/TB/year) | ~$360/TB over 5yr — scales linearly, no flat tier |
Notice the structural difference already visible in that table: the three consumer sync services cluster around $500–$600 for 2TB over 5 years regardless of provider, because they're all pricing a bundled convenience product. Backblaze B2 is a different category — genuine per-GB object storage with no flat consumer tier — and its cost simply multiplies with capacity: 10TB runs roughly $3,600 over 5 years, 30TB roughly $10,800, before any egress fees for getting data back out. There is no consumer-priced way to store 10–30TB in the cloud; you either pay object-storage rates or you don't do it at all.
What does the NAS side of the ledger look like?
NAS cost has three components, and only one of them (electricity) is a genuine recurring bill:
- Enclosure — a one-time cost, described in bands, not prices. Budget 2-bay units, mainstream 2–4 bay units, and prosumer 4-bay units occupy successively higher price bands; see best 2-bay NAS and best 4-bay NAS for current picks and live pricing links. Amortized over a realistic 5–8 year hardware life, the enclosure's annual cost is small regardless of which band you buy into.
- Drives — the real capacity cost, roughly $15–25 per TB. NAS-rated CMR drives (never SMR — see CMR vs SMR) commonly run in this approximate range per terabyte as of mid-2026; it's a general market band, not a specific product price, and shifts with capacity tier and brand. A 2TB mirror needs roughly 4TB of raw drive capacity; a 10TB usable array in RAID 5/SHR-1 needs roughly 12–14TB raw; a 30TB array needs roughly 35–40TB raw, before redundancy overhead gets worse at larger drive counts.
- Electricity — the one true recurring cost, ~$25–60 per year. A 2-bay unit runs about $25–45/yr; a 4-bay with more drives spinning runs about $35–60/yr (full breakdown: power consumption truth). Over 5 years that's roughly $125–300 total — real, but small next to either the hardware or a multi-TB cloud bill.
- Drive-replacement probability — budget for one. Backblaze's published fleet data puts annualized CMR drive failure rates in the low single digits (commonly ~1–2%/drive-year). Across a 4-drive array over 5 years, that compounds to roughly a one-in-four to one-in-three chance that at least one drive needs replacing — a real cost the "buy once, done" framing skips. Honest 5-year NAS math includes one replacement drive's worth of the per-TB band above.
The honest crossover: which wins, by capacity and time horizon?
| Capacity | 1 year | 3 years | 5 years |
|---|---|---|---|
| ~2TB (casual files, photos) | Cloud — no upfront hardware cost to recover yet | Close — NAS hardware is largely paid off in amortized terms | Toss-up — cloud ~$500–600 total vs. NAS's front-loaded cost plus ~$125–225 electricity; other factors (maintenance appetite, offsite-by-default) should decide |
| ~10TB (media library, growing archive) | NAS — object-storage cloud (~$720/yr) already exceeds a NAS's first-year cost | NAS clearly — ~$2,160 in cumulative cloud object-storage fees vs. a mostly-paid-off NAS | NAS decisively — ~$3,600 cumulative cloud vs. a NAS whose recurring cost is only electricity plus an occasional drive |
| ~30TB (large media/homelab archive) | NAS — consumer cloud tiers don't reach this size at all; object storage runs ~$2,160/yr | NAS decisively — ~$6,480 cumulative object-storage cost | NAS overwhelmingly — ~$10,800 cumulative cloud cost vs. a NAS's flat electricity-plus-drives bill |
Two caveats the table can't carry on its own. First, cloud still wins outright below ~1–2TB — zero maintenance and offsite-by-default are worth real money to a casual user, and this page isn't arguing otherwise (see the fuller philosophy in our NAS vs. cloud honest-math piece). Second, and more important: a NAS alone is not a backup. RAID is not a backup — it protects against a drive dying, not deletion, ransomware, or a fire in your house. Any honest 5-year NAS total should include a modest offsite tier (a curated subset on B2/S3-class object storage, per the 3-2-1 rule), which narrows — but doesn't erase — the NAS's cost advantage at multi-TB scale.
Related reading
Frequently Asked Questions
It depends almost entirely on how many terabytes you store. At a 2TB scale, five years of a consumer cloud subscription (Google One, Dropbox, iCloud+) runs roughly $500–$600 total, in the same ballpark as a budget 2-bay NAS's amortized hardware share plus its electricity over the same period — a genuine toss-up. At 10TB and 30TB the picture flips hard: consumer cloud tiers barely exist at that size, so you're pushed into per-GB object storage (Backblaze B2-class) billed monthly forever, while a NAS's cost is front-loaded once and then nearly flat. The crossover point is capacity, not time.
Roughly above the 4–8TB range for most households, and unambiguously above 10TB. Below ~2TB, cloud wins outright — the subscription plus zero maintenance beats owning hardware you'd need to tend. Between roughly 2–8TB it's close enough that other factors (do you want a hobby, do you need local speed, is your data still growing) should decide. Above 10TB, consumer cloud pricing either steps up sharply or stops being offered at all, and the 5-year math tilts firmly toward a NAS plus a small offsite backup tier.
Modestly. A typical always-on 2-bay NAS runs about $25–$45 per year in electricity; a 4-bay with more drives runs about $35–$60 per year (see our full power-consumption breakdown). Over 5 years that's roughly $125–$300 total — a real cost, but small next to the hardware itself, and far smaller than 5 years of a cloud subscription once you're storing more than a couple of terabytes.
Published large-fleet drive data (Backblaze's annual reports) puts NAS-rated CMR drive annualized failure rates in the low single digits — commonly cited around 1–2% per drive-year, though it varies by model and age. Across a 4-drive array over 5 years, that works out to roughly a one-in-four to one-in-three chance that at least one drive fails and needs replacing. Budget one replacement drive into any honest 5-year NAS estimate — it rarely changes which side wins, but it's a real line item most marketing skips.
Not indefinitely — subscription pricing changes with promotions, currency, and product repositioning (Google folding storage into "Google One AI Pro" bundles is a recent example). The figures on this page are a snapshot as of July 2026, useful for the shape of the comparison and the order of magnitude, not as a live price quote. Always check each provider's current pricing page before deciding.
No. A NAS is one copy in one building, and RAID inside it only protects against a drive failing — it isn't a backup (see why RAID is not a backup). Consumer cloud sync tools like Dropbox and Google Drive replicate accidental deletions and ransomware just as fast as RAID does. Whichever side of this cost comparison you land on, the honest 3-2-1 answer still applies: NAS or cloud as your primary, plus a separate versioned, ideally offline/offsite copy.
How we work
We're a research-based site: this comparison uses published subscription rates (snapshot, July 2026), general cost bands for electricity and drive-cost-per-TB, and formula-based arithmetic — never exact hardware prices, per Amazon's Operating Agreement. Figures are estimates for understanding the shape and scale of the tradeoff, not a live quote for your specific setup. Read our full methodology →