NAS vs Cloud Cost Calculator

Why the sticker price lies about storage

A 2 TB cloud plan looks cheap next to a NAS box that costs two or three hundred dollars — until you multiply the subscription by five years. The real question is never "what does it cost today", it is "what does it cost over the years I will actually use it". A NAS has a big upfront bill and then sips electricity; cloud storage has no upfront bill but charges you rent forever. This calculator puts both on the same timeline so you can see the true multi-year cost.

How the comparison works

You enter how many terabytes you need, how many years you plan to keep them, your NAS hardware price, the size and price of the drives, a RAID setup, and the NAS's monthly electricity cost. The calculator figures out how many drives you need — rounded up, with extra drives for mirroring or RAID 5 parity — adds the electricity over your horizon, and totals the NAS. On the cloud side it sizes each provider's plan to your storage need: a 4 TB need takes two 2 TB Google One or Dropbox plans but four 1 TB Microsoft 365 plans. Google One (2 TB at $9.99/month), Dropbox (2 TB at $11.99/month) and Microsoft 365 (1 TB at $6.99/month) are compared side by side against the NAS, and the cheapest cloud plan sets the breakeven point.

Worked example

Take a 4 TB photo and video library you plan to keep for 5 years. A $250 two-bay NAS with two mirrored 4 TB drives at $100 each costs $450 in hardware, plus $3 a month in electricity. The NAS total is $630. Cloud: Google One needs two 2 TB plans at $19.98 a month, which is $1,198.80 over five years; Dropbox comes to $1,438.80 and Microsoft 365 to $1,677.60. The NAS saves $568.80 and pays for itself in about 2.2 years — after that your storage is nearly free. Now flip it: 1 TB for 2 years, $270 of NAS hardware and the same electricity. The cheapest cloud plan (Microsoft 365 at $6.99 a month) costs $167.76 over two years, while the NAS costs $342. Here the NAS would need about 5.6 years to pay for itself — longer than you plan to keep it — so cloud wins.

Practical tips

First, storage needs only grow, so plan for the terabytes you will have in three years, not today. Second, RAID is not a backup — mirroring protects against one dead drive, not against theft, fire or accidental deletion, so budget an offsite copy if the data matters. Third, electricity is small but not zero: a NAS running 24/7 adds up over a decade. And finally, factor in convenience: cloud plans give you access from anywhere with no maintenance, while a NAS gives you privacy and no monthly rent. The math tells you which is cheaper; your habits decide which is better.