Turn Your Plex Library into Terabytes
Turn your library into terabytes, a RAID array, and the live cost to build it
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This calculator turns your library (4K movies, 1080p movies and TV episodes) into the terabytes you need, a sensible RAID array to hold it, and the live cost to buy the drives, with a shucking saving on top. As a rule of thumb, a 4K movie is 15 to 30 GB encoded or 50 to 90 GB as a remux, a 1080p movie is 4 to 10 GB, and a TV episode is 1 to 3 GB, so a 500-movie 4K encode library plus some TV lands around 12 to 18 TB before growth. Enter your counts above to get your number and today's cheapest way to buy it.
The sizing anchors, honestly
There is no single average file size, so this tool uses honest ranges and lets you pick the 4K quality. A 4K remux keeps the untouched disc bitrate and runs 50 to 90 GB per movie; a 4K encode (re-compressed with HEVC) is 15 to 30 GB for near-identical quality on most screens. 1080p movies land at 4 to 10 GB, and TV episodes at 1 to 3 GB each. The calculator uses a midpoint of each range for the estimate, which is close enough to plan a build.
The quality mix is the biggest lever. A library of 4K remuxes needs several times the space of the same films encoded, so the remux-versus-encode toggle changes the answer more than the movie count does. Be honest about which you actually keep, because sizing for remux when you encode wastes money, and the reverse leaves you short.
From terabytes to an array, to a price
Once the calculator has your total, it sizes a real array using the same RAID math as the site's calculators: usable capacity is the data drives times their size, minus parity, times about 0.91 for binary and filesystem overhead. Pick your drive size and redundancy and it shows how many drives to buy and the usable result, for example four 16 TB drives in RAID-Z1 giving roughly 43 TiB usable.
Then it prices it live. The drive cost multiplies the raw terabytes by today's cheapest NAS-rated CMR price per terabyte, and the shucking line shows what the same capacity costs from the cheapest current shuckable external, so you can see the saving before you buy. The matching-drive BuyBlock lists the actual cheapest drives at your chosen size, and the links route you to the drives calculator and the four builds by fit.
Do not forget transcode scratch space
The calculator sizes your library, but Plex also needs a little temporary space when it transcodes. Each active transcode writes segments to a scratch directory (by default in the Plex data folder), which can grow to a few gigabytes to tens of gigabytes under several concurrent streams. It is temporary, not part of your library, so keep it on the boot SSD or point it at a RAM-disk, and do not count it in the storage figure above.
A 100-movie 4K (encode) + 300-movie 1080p + 500-episode library needs about 6.9 TB usable with 30% growth headroom. That is about 3 drives of 16 TB in RAID-Z2 / RAID 6 (~15 TiB usable after parity and overhead), costing about $1,040 at today's cheapest $21.67/TB.
Cut this with shucking: the same 48 TB is about $77 shucked today, roughly $963 less. Check the shucking tracker for the live delta.
Sizes use honest per-title ranges: 4K remux 50-90 GB, 4K encode 15-30 GB, 1080p movie 4-10 GB, TV episode 1-3 GB. Add a few GB to tens of GB of transcode scratch space separately (or point it at a RAM-disk). This estimates real usable capacity; parity is not a backup.
Frequently asked questions
How much storage space do I need for a Plex server?
It depends on your library and quality mix. As a guide, a 4K movie is 15 to 30 GB encoded or 50 to 90 GB as a remux, a 1080p movie 4 to 10 GB, and a TV episode 1 to 3 GB. A typical 500-movie mixed library lands around 20 to 40 TB. Enter your counts in the calculator for your exact number plus growth headroom.
How many 4K movies can 1 TB hold?
Roughly 11 to 65, depending on quality. At 15 to 30 GB for a 4K encode you fit about 33 to 65 movies per terabyte; at 50 to 90 GB for a 4K remux only about 11 to 20. Encoded 4K stores several times more per terabyte than remux, which is why the quality mix drives your total.
How much space does Plex need for transcoding?
Only temporary scratch space, not permanent storage. Each active transcode writes segments to a scratch directory, totalling a few gigabytes to tens of gigabytes under several concurrent streams. Keep it on the boot SSD or a RAM-disk; it clears when the stream ends and is separate from your library size.
How many GB of RAM for Plex?
8 to 16 GB covers almost every Plex server, because Plex itself is light on memory. You only need 32 GB or more for a ZFS pool's ARC cache, for containers and virtual machines, or for RAM-disk transcoding. RAM does not affect storage size or transcoding capacity; size storage with this calculator and RAM to the platform.
How do I calculate storage for a growing library?
Estimate your current library, then add growth headroom, which this calculator does with a slider. Media libraries grow steadily, so sizing for today leaves you rebuilding soon; adding 20 to 40 percent headroom, and buying fewer larger drives, gives room to expand without wasting money now.