ubnas

The classic NAS mistake is buying six 8 TB drives and discovering how much less than 48 TB you actually get to use. ubnas starts there. Its capacity calculator takes the number of drives and their sizes, mixed sizes included, and a layout such as RAID 5, RAID 6, RAID 10, RAIDZ1 to RAIDZ3, ZFS mirrors, Synology's SHR or Unraid. It returns usable space in TB and in TiB, which is the smaller number your NAS will show, along with how many drives can fail, the efficiency and the space lost to parity. Six 8 TB drives in RAID 6 come out at 32 TB usable, about 29.1 TiB, surviving two failures.

Two other calculators answer the next questions. The power cost calculator turns idle watts, drive count and your electricity price into a yearly figure. The SSD endurance calculator uses a drive's TBW rating and your daily writes, including cache write amplification, to estimate years of life. Every result shows the formula, and you can change any assumption you disagree with. All three run in the browser with no sign-up.

The site also has 54 guides across NAS buying advice, storage, self-hosting, backup and homelab topics. They range from CMR versus SMR drives and RAID 5 versus RAID 6 versus SHR to Docker PUID and PGID permissions, Tailscale access rules for a NAS and replacing a failed drive without losing the array. The about page sets a clear boundary. ubnas doesn't run a hardware lab, takes specifications from manufacturer datasheets and reliability figures from public data such as Backblaze Drive Stats, and links its sources so you can check them. The homepage counts 262 cited sources.

Anyone pricing up a first NAS or a homelab upgrade who wants to know usable space, running cost and drive life before ordering parts. It is also handy for settling the SHR versus RAID or TrueNAS versus Unraid questions that come up once the box arrives.

The site is free and reader supported. Some links are affiliate links, and the about page says commissions don't decide recommendations. The privacy policy covers Google Analytics, possible third-party ads with personalised ad cookies, and affiliate cookies. It names the operator only as the ubnas team.