NAS, RAID and Backup Storage
Cloud backup vs NAS break-even.
A NAS has a one-off cost plus small running costs; cloud backup is billed every month on the TB you store. Break-even is the first month when your cumulative NAS cost is no higher than your cumulative cloud cost. For 10 TB growing 0.2 TB a month at $6 per TB-month against a $1,200 NAS that costs $5 a month to run, that is month 19. Runs in your browser; nothing is sent or stored.
Your costs
Break-even
Fill the form and press Calculate.
Worked example
10 TB today growing 0.2 TB a month, cloud at $6 per TB per month, a $1,200 NAS with drives costing $5 a month to run. After 12 months cloud has cost $799.20 against $1,260.00 for the NAS; after 24 months it is $1,771.20 against $1,320.00. The NAS total first drops below the cloud total in month 19. After 60 months the cloud has cost $5,724.00 and the NAS $1,500.00, a gap of $4,224.00.
How it works
Cloud cost in month m = price per TB-month x (data today + growth x (m - 1)). The NAS costs one-off cost + monthly running cost x months. The tool adds each month up and reports the first month where the NAS total is no higher than the cloud total.
It uses only your inputs, so check your provider's current price, egress and minimum-term fees yourself. It leaves out drive replacement, a second NAS, your time and any bandwidth limits, and it assumes the NAS holds all your data. See the space you need with the 3-2-1 backup storage calculator and the real purchase-plus-power cost of drives with the hard drive cost per TB calculator. This is a cost comparison, not financial advice.
Estimates only. RAID is not a backup: it keeps an array running through a drive failure but does not protect against deletion, malware, fire or theft. Real arrays and drives vary, so use this for planning and check your own drive datasheets.
Sources and basis (opened 2026-10-08):
- Data Backup Options (CISA, Ruggiero and Heckathorn): The 3-2-1 rule needs one copy offsite, which is why a home NAS does not replace an offsite or cloud copy. Prices and costs on this page are entirely your own inputs.
FAQ
Is a NAS cheaper than cloud storage?
It depends on how much data you store and for how long. A NAS has a large one-off cost and small running costs, while cloud is billed every month, so the NAS usually wins on large data over several years. Enter your own numbers to see.
How do I calculate NAS break-even?
Add the NAS price and its running costs month by month, add the cloud bill month by month, and find the first month the NAS total is not above the cloud total. In the example that is month 19.
Does this include the cost of replacing drives?
No. Add a share of future drive purchases to the one-off cost if you expect to replace them within the period.
Do I still need cloud backup if I buy a NAS?
Usually yes for an offsite copy. The 3-2-1 rule asks for three copies, two media types and one copy offsite, and a NAS at home is on-site.
What cloud price should I enter?
Use the current per TB per month price from the provider you would actually use, including any extra fees you expect to pay. The 6 in the example is only a placeholder.