Video / ProRes Storage Calculator

About Video / ProRes Storage Calculator

How Video File Size Is Calculated

For constant-bitrate codecs like ProRes and DNxHR, file size scales linearly: File Size = Bitrate x Duration. The bitrate for these codecs is determined by the resolution, frame rate, and quality tier. For variable-bitrate codecs like H.264 and H.265, the calculator uses typical average bitrates for each quality tier.

Factor	Effect on File Size	Example
Resolution (2x)	~4x file size	1080p to 4K = 4x more pixels per frame
Frame rate (2x)	~2x file size	24 fps to 48 fps = twice as many frames
Codec quality tier	2x-10x depending on codec	ProRes 422 Proxy vs ProRes 4444 XQ = ~6x difference
Colour depth	~1.5x for 10-bit vs 8-bit	10-bit captures finer colour gradations

Codec Comparison at 4K 24fps (1 Hour)

Codec / Quality	Typical Bitrate	1 Hour at 4K 24fps	Use Case
H.264 Low	~20 Mbps	~9 GB	Web delivery, proxies, social media
H.264 Medium	~45 Mbps	~20 GB	Streaming master, good quality archive
H.264 High	~100 Mbps	~45 GB	High-quality delivery, camera recording
H.265/HEVC Medium	~30 Mbps	~13.5 GB	Same quality as H.264 Medium at ~40% less size
ProRes 422 Proxy	~66 Mbps	~30 GB	Offline editing proxies
ProRes 422 LT	~132 Mbps	~59 GB	Lightweight editing, review copies
ProRes 422	~198 Mbps	~89 GB	Standard production codec, post-production
ProRes 422 HQ	~264 Mbps	~119 GB	High-quality mastering and grading
ProRes 4444	~396 Mbps	~178 GB	VFX work, alpha channels, colour-critical
ProRes 4444 XQ	~594 Mbps	~267 GB	Highest-quality ProRes, HDR mastering
DNxHR HQ	~264 Mbps	~119 GB	Avid Media Composer editing
Blackmagic RAW 5:1	~340 Mbps	~153 GB	Camera RAW with moderate compression
CinemaDNG (RAW)	~900+ Mbps	~405 GB	Uncompressed RAW, maximum flexibility

ProRes Family Comparison

Apple ProRes is a family of six codecs with different quality-to-size trade-offs. All are constant bitrate (CBR), so file sizes are perfectly predictable. ProRes rates are published by Apple and scale linearly with resolution and frame rate.

ProRes Variant	Quality	Data Rate (1080p 24fps)	Colour Depth	Alpha Channel
422 Proxy	Lowest - for offline editing	~15 Mbps	10-bit 4:2:2	No
422 LT	Light - 70% of 422 size	~26 Mbps	10-bit 4:2:2	No
422	Standard production quality	~37 Mbps	10-bit 4:2:2	No
422 HQ	Broadcast and mastering	~56 Mbps	10-bit 4:2:2	No
4444	VFX and grading	~84 Mbps	12-bit 4:4:4	Yes (up to 16-bit)
4444 XQ	Highest quality	~126 Mbps	12-bit 4:4:4	Yes (up to 16-bit)

The 4:2:2 in "ProRes 422" refers to chroma subsampling - the colour information is sampled at half the horizontal resolution of the luminance. ProRes 4444 samples colour at full resolution (4:4:4), which matters for green screen keying and colour grading.

Storage Planning for Shoots

Knowing your file sizes lets you calculate how much storage to bring on location. The calculator shows how many hours of footage fit on common drive sizes, but here is a quick reference for ProRes 422 at popular resolutions:

Drive Size	1080p 24fps	1080p 60fps	4K 24fps	4K 60fps
256 GB	~15.5 hours	~6.2 hours	~2.9 hours	~1.2 hours
512 GB	~31 hours	~12.4 hours	~5.8 hours	~2.3 hours
1 TB	~62 hours	~24.8 hours	~11.5 hours	~4.6 hours
2 TB	~124 hours	~49.6 hours	~23 hours	~9.2 hours
4 TB	~248 hours	~99.2 hours	~46 hours	~18.4 hours
8 TB	~496 hours	~198.4 hours	~92 hours	~36.8 hours

A good rule: bring at least 50% more storage than you think you need. Shoots always run longer than planned, and having to stop because you ran out of drive space is the worst possible outcome.

H.264 vs H.265 (HEVC) vs AV1

Codec	Compression Efficiency	Encoding Speed	Hardware Support	Best For
H.264 / AVC	Baseline	Fast	Universal - every device since ~2010	Compatibility, real-time streaming, fast turnaround
H.265 / HEVC	~40% smaller at same quality	2-3x slower to encode	Most devices since ~2017	4K delivery, storage-constrained archives
AV1	~50% smaller than H.264	Very slow (software), fast with hardware encoders	Recent GPUs and devices (2022+)	Web streaming, YouTube, future-proof archiving

For delivery (web, streaming, sharing), H.265 and AV1 save significant storage at the same visual quality. For production (editing, grading), ProRes and DNxHR are preferred because they decode faster and handle repeated re-encoding without quality loss.

Camera Recording Formats

Camera System	Common Format	Typical 4K Bitrate	1 Hour at 4K
iPhone / smartphone	H.265 / HEVC	~135 Mbps (ProRes on iPhone 15 Pro+)	~60 GB (HEVC) or ~135 GB (ProRes)
Mirrorless (Sony, Canon)	H.264/H.265 (internal), ProRes (external recorder)	100-400 Mbps	45-180 GB
Blackmagic Cinema	Blackmagic RAW	200-900 Mbps	90-405 GB
RED	REDCODE RAW	300-1200 Mbps	135-540 GB
ARRI	ARRIRAW / ProRes	500-2800 Mbps	225 GB - 1.26 TB

Worked Example: Budgeting Storage for a 3-Day Shoot

A realistic planning exercise: three 10-hour shoot days at 4K UHD, 24 fps, in ProRes 422 HQ, with one backup copy on set.

Step 1 - Data rate: ProRes 422 HQ scales from its published 220 Mbps (1080p, 29.97fps) by (3840 x 2160) / (1920 x 1080) = 4x for resolution and 24 / 29.97 = 0.801 for frame rate. That is 220 x 4 x 0.801 = 705 Mbps, or 88.1 MB/s.

Step 2 - Hourly size: 88.1 MB/s x 3600 s = 317 GB per hour. Apple publishes this same figure in the ProRes White Paper (June 2023), which lines the calculator up directly with the reference spec.

Step 3 - Shoot total: 30 hours x 317 GB = 9,510 GB, roughly 9.51 TB across the three days.

Step 4 - Backup and headroom: Mirrored on-set backup doubles it to 19 TB. Add 30% headroom for retakes and accidental long takes, and you are planning for ~25 TB. That fits comfortably on two 16 TB SSDs or one 20 TB SSD with a bootable backup drive. Skimping on headroom is the most common mistake productions make - running out of media at lunchtime on day two is a classic and expensive error.

What Is a Good Codec for Long-Term Archival?

ProRes 422 HQ and DNxHR HQX are the industry-standard archival masters, because both are mathematically lossless for successive re-encodes and have decades of vendor support. The Library of Congress Recommended Formats Statement (2024-2025) lists ProRes and JPEG 2000 as preferred archival video codecs, alongside FFV1 for lossless preservation. Long-GOP codecs like H.264 and H.265 are not recommended as masters because each re-encode compounds compression artefacts.

For offsite backup, LTO tape remains cheaper per terabyte than spinning disks for anything over ~50 TB, with LTO-9 tapes storing 18 TB native and rated for 30+ year shelf life per the LTO Program. Many post houses use a "3-2-1" rule: three copies, two different media types, one offsite.

Common Mistakes That Waste Storage

• Recording in 4K when delivering in 1080p. Unless you need reframing latitude, 1080p ProRes 422 uses 25% of the storage of 4K ProRes 422 for broadcast-grade output. Shooting 4K for a 1080p web deliverable is defensible; shooting 8K for 1080p is rarely justified.
• Leaving camera cards in "All-I" mode for B-roll. All-intraframe recording on modern mirrorless cameras can double bitrate with no visible quality gain on static shots. Use Long-GOP for interview B-roll, All-I only for fast action or future VFX plates.
• Archiving uncompressed RAW. Blackmagic RAW 5:1 or REDCODE RAW at standard compression ratios are visually identical to uncompressed for almost all projects and save 60-80% of the space. ARRI themselves ship ARRIRAW at 12-bit compressed by default.
• Confusing megabits and megabytes. A 150 Mbps bitrate is 18.75 MB/s, not 150 MB/s. The bitrate calculator is handy when cross-checking camera spec sheets against NLE readouts.
• Forgetting sidecar files. .RMD files, proxy folders, LUT files and camera metadata can add 5-10% to the apparent clip size. Always budget that on top of raw codec maths.

How Accurate Are These Estimates?

Constant-bitrate codec estimates are usually within 1-2% of actual file size. Apple publishes ProRes rates as target data rates rather than averages, so 1 hour of ProRes 422 HQ at 1080p, 29.97 fps will land almost exactly on the stated 220 Mbps x 3600 / 8 = 99 GB. DNxHR HQ behaves the same way because Avid publishes fixed rate tiers.

Variable-bitrate codec estimates (H.264, H.265, AV1) can be off by 20-40%. A locked-off interview with a static background compresses much smaller than the quoted bitrate; a concert with strobing lights and smoke can run 50% higher. The numbers here assume "typical" content - indoor documentary, outdoor action, narrative drama. For compression-heavy content like sports broadcasts, budget the next tier up.

Once you have planned the storage, the file transfer time calculator estimates how long it will take to move clips from card to drive, and the storage converter handles GB/TB and binary equivalents when drive manufacturers and operating systems disagree. All calculations run in your browser with nothing sent to a server.

Sources

• Apple - ProRes White Paper (published data rates)
• Avid - DNxHR and DNxHD Codec Bandwidth Specifications
• ITU-T H.265 (HEVC) Recommendation
• Alliance for Open Media - AV1 Bitstream and Decoding Process Specification
• Library of Congress - Recommended Formats Statement (Moving Image Works)
• LTO Program - Ultrium Generation Specifications
• Blackmagic Design - Blackmagic RAW Specification