PostMicroTools
Calculator
RAID & video storage calculator
Two calculators in one: size a RAID array — usable capacity, overhead and fault tolerance for RAID 0/1/5/6/10 — and work out how much storage you need for ProRes, DNxHR, camera RAW or image sequences.
RAID calculator
Visual · no setup neededPick a RAID level, number of disks and disk size — see usable capacity, fault tolerance and what each disk does in the array.
- RAID 0 — stripe: all capacity, no redundancy (fastest, riskiest).
- RAID 1 / 10 — mirror: half the capacity, survives a disk loss.
- RAID 5 — single parity: loses one disk of capacity, survives one failure.
- RAID 6 — dual parity: loses two disks, survives two simultaneous failures.
How to plan your storage
Rule of thumb: estimate the raw footage, add room for proxies, renders and backups (multiply ×2–3 if you follow the 3-2-1 rule), and always keep 20% headroom on each drive.
Why GB in base 1000 and not 1024?
Drive makers sell in base 1000 (1 TB = 1,000 GB). The OS sometimes shows base 1024 (GiB/TiB), which is why a “2 TB” drive appears as ~1.82 TiB. We use base 1000 here to match the advertised capacity.
Do RAW formats always compress the same?
No. REDCODE, BRAW and X-OCN use lossy compression that varies with content (more detail and motion = larger files). The ratio you pick is the average target; the result is an estimate.
How does the RAID calculator work?
Pick a RAID level (0, 1, 5, 6 or 10), the number of disks and the disk size. It shows raw vs usable capacity, the storage overhead and how many disks can fail without losing data — so you can size an array for your footage and backups.
RAID 5 vs RAID 6 — which should I use?
RAID 5 (single parity) survives one disk failure; RAID 6 (dual parity) survives two. For arrays of six or more large disks, RAID 6 is the safer choice because rebuilds take long enough that a second failure becomes a real risk.
Planning media for a shoot, not just a file
A DIT's day starts with this math. A documentary crew shooting 4 hours a day of UHD BRAW 5:1 at 25p generates on the order of 1 TB per day; a 15-day shoot is 15 TB of camera originals before a single backup. With the industry-standard 3 copies (camera master, working copy, off-site), you are really provisioning about 45 TB of storage for that job.
The spread between codecs is enormous and this is where budgets are won or lost. An hour of ARRIRAW at 4.5K is several times the size of the same hour in ProRes 4444, which in turn dwarfs an hour of ProRes 422 proxies. Producers who compare those columns before the shoot pick the codec that matches the finishing pipeline instead of paying for headroom nobody will use.
The calculator covers ProRes, DNxHR, REDCODE, BRAW, ARRIRAW, X-OCN and image sequences (EXR/DPX/TIFF) — the last of which matters to VFX: a 1000-frame UHD half-float EXR shot is measured in tens of gigabytes, so a 40-shot sequence needs real server space. Capacity is only half the answer — check the array can actually sustain the playback rate with the disk throughput calculator.
How much extra headroom should I add per shoot day?
A common rule is 15–20% over the calculated figure: retakes, second cameras rolling longer than planned, and mixed frame rates all push the real number up. Running out of media on set costs far more than the extra card or drive.
Do I multiply by the number of backup copies?
Yes. The 3-2-1 practice (three copies, two media types, one off-site) means total provisioned storage is roughly 3× the camera-original figure, even if the working copy lives on a shared server.
Why do image sequences take so much more space than video files?
Every frame is a standalone file with no interframe compression. A UHD 16-bit half-float EXR frame is typically 20–50 MB depending on channels and compression, so seconds of footage become gigabytes — which is why VFX plates are budgeted separately from editorial media.