The right answer is not "as big as I can afford." The right answer is "enough for one full project plus thirty percent." That math gives you a drive that performs well, holds the entire job without juggling, and is replaceable when you outgrow it instead of being a forever commitment.
Sizing a drive for video editing is more like loading a grip truck than packing a suitcase. You do not pack everything you own. You pack everything for the current job, plus the gear you might pull from for the next one, plus enough room to actually move around inside the truck. Pack any tighter and the gear gets damaged.
The Math: Shoot Ratio Times Project Length Times Codec
Your storage need is three numbers multiplied together.
Codec rate is how much storage the camera generates per minute. ProRes 422 HQ at 4K is about 38 GB per hour, or 600 MB per minute. R3D 8K is about 90 GB per hour. H.265 4K from a mirrorless camera is around 7 GB per hour.
Shoot ratio is how much footage you generate for every minute of finished video. A documentary might shoot 50:1. A YouTube vlog might shoot 5:1. A wedding is typically 8-10:1.
Project length is the duration of the finished piece.
Multiply those together and you get the camera-original storage for the project. Then add another 50-100 percent for proxies, cache, exports, graphics, music, and the seventeen versions of the cut. The full project rarely fits in just the camera originals.
Here is what that looks like for some typical jobs.
| Job type | Codec | Shoot ratio | Camera originals | Full project |
|---|---|---|---|---|
| Wedding (8 hr, RED Komodo) | R3D HQ 6K | 8:1 | ~1.4 TB | ~2-3 TB |
| Wedding (8 hr, FX3) | XAVC-I 4K | 8:1 | ~700 GB | ~1.5 TB |
| YouTube vlog (12 min cut) | H.265 4K | 5:1 | ~7 GB | ~30 GB |
| Doc episode (45 min cut) | ProRes 422 HQ | 30:1 | ~850 GB | ~1.5 TB |
| Commercial (60 sec cut) | ARRIRAW 4.5K | 100:1 | ~1.2 TB | ~2.5 TB |
| Reality season (10 episodes) | XAVC-I 4K, multicam | 200:1 | ~30 TB | ~60 TB |
Your numbers will vary, but this is the order of magnitude.
The 30 Percent Rule
Drives degrade past 80 percent full. SSDs especially. When an SSD crosses about 80 percent capacity, the controller has fewer free blocks to work with for garbage collection and write amplification, and write speeds drop noticeably. On many consumer SSDs you lose 30 percent of your write speed in the last 20 percent of capacity.
That is exactly the moment you do not want to be slower: you are usually deep into a project, doing the heaviest writes (renders, exports, cache rebuilds), and the drive is fighting you.
So the rule is: size your drive so the full project fits in 70 percent of the capacity. If a project fits in 1 TB of files, buy a 1.4 to 1.5 TB drive. Realistically, 2 TB, since drives come in standard sizes.
This is not optional. Editors who run drives at 95 percent for months wonder why their export times doubled. The drive did not fail. It is just being throttled by its own firmware to stay alive.
Right Size by Job Type
If you do not want to do the multiplication every time, here is the working drive size for common editor profiles. These assume one project at a time on the drive, with the 30 percent headroom built in.
| Editor type | Recommended working drive |
|---|---|
| Wedding videographer (single shooter) | 4 TB |
| Wedding videographer (RED or multi-cam) | 8 TB |
| YouTube creator (mostly H.265) | 2-4 TB |
| Documentary editor (long-form) | 8-12 TB |
| Commercial editor (short-form, raw) | 8 TB |
| Doc series or multi-episode | 16-20 TB |
| Reality season | 60+ TB (this is NAS territory) |
| Hobbyist / one-off | 2 TB |
Notice how fast the numbers escalate once you cross into multicam or long-form. A wedding videographer can live on a single 4 TB SSD. A reality editor cannot live on anything portable.
Active Drive vs Archive Drive
A common mistake is buying one giant drive and trying to keep everything on it. Three years in, you have a 16 TB drive holding eight years of projects, and you cannot tell what is current, what is archive, and what is abandoned.
Better approach: separate your active drive from your archive. The active drive holds whatever you are working on right now plus the last few months. The archive drive holds delivered projects you might revisit. The active drive can be small and fast (NVMe, Thunderbolt). The archive drive can be large and slow (spinning disk, USB).
Rotating projects between active and archive is also when you can audit. Before a project moves to archive, that is the natural moment to delete unused footage, flatten renders, and trim the project to just what was actually used.
When to Scale Up vs Spin Off
At some point a single external drive stops being the right answer. The break-even is roughly when you are buying your fourth or fifth drive in two years.
Stick with single drives if you do one project at a time, work alone, and like the simplicity. The whole project on one drive that you can throw in a bag is genuinely useful.
Move to a NAS or DAS when you cross about 30 TB of active storage need, when you are sharing files with another editor or producer, or when you are doing project archiving at any meaningful volume. A Synology or QNAP NAS at 8-bay capacity gets you 60-80 TB usable for less than the per-TB cost of buying that many external SSDs separately.
Move to LucidLink, Frame.io Drive, or similar cloud streaming when team collaboration matters more than local speed, or when you have multiple editors in different cities working on the same job.
The math is mostly about how many drives you would otherwise be buying and shuffling. If you are buying one 4 TB SSD every quarter, a NAS pays back inside a year.
How to Avoid Buying More Than You Need
Most "I need a bigger drive" moments are actually "I never cleaned the last drive" moments. Cache files, abandoned projects, and unused footage often account for 40-50 percent of any working drive over a year old.
Before you size up, the storage calculator can give you an honest read on what your real working set should be based on your shoot volume. Compare that to what is actually on your current drive. If the gap is large, the cleanup buys you the same outcome as the new drive without spending the money.
Before You Click Buy
It is worth knowing what kind of files are eating your current drive before you order the next one. Clip Sweeper scans your Premiere projects and tells you which media files are actually used on a timeline versus which are just sitting in bins. On a typical drive, that single scan reclaims more space than upgrading from a 4 TB to an 8 TB. The new drive is fun. Not needing the new drive is better.