Pick a codec, a resolution, a frame rate and a duration. The calculator gives the file size in GB and the bitrate in Mbps. One hour of ProRes 422 HQ at 1080p, 23.976 fps is 176 Mbps and 79 GB; the same hour in UHD 4K is 707 Mbps and 318 GB.
Where the numbers come from
ProRes uses Apple's own target data rates, from the appendix of the Apple ProRes White Paper (April 2022, read 23 September 2026). Apple lists a rate for each ProRes flavor at each frame size and frame rate, and the calculator uses those figures unchanged.
H.264 and H.265 have no single published rate. Their size depends on the bitrate the camera or encoder chose, and that varies widely, so the calculator asks for your bitrate. For H.264 it starts from YouTube's recommended upload bitrates (read 23 September 2026): 8 Mbps for 1080p at 24 to 30 fps, 12 Mbps at 48 to 60 fps, and 35 to 45 Mbps for 2160p (53 to 68 Mbps at high frame rates). Where YouTube gives a range, the calculator uses the low end. Replace it with your camera's or encoder's number. For a file you already have, MediaInfo shows it.
Assumptions
- Video only. Audio, the container and ProRes alpha channels add to the real file. Apple's rates are for 4444 and 4444 XQ without alpha.
- Target rate, not a guarantee. Apple describes ProRes as variable bit rate. Most frames land close to the target, simple frames use fewer bits, and no frame exceeds the target by more than about 10 percent. Real files come in at or a little under these sizes.
- Apple's 24p, 30p and 60p rows are 23.976, 29.97 and 59.94 fps. The white paper's own chart gives 117 Mbps for ProRes 422 at 1920 x 1080 and 23.976 fps, the same figure as its 24p row. For 24, 30 and 60 fps exactly, the calculator scales that row by the frame rate, because Apple defines the data rate as a target number of bits per frame multiplied by the frame rate. The difference is 0.1 percent.
- Decimal units. 1 GB = 1,000 MB = 1,000,000,000 bytes, which is how macOS Finder and drive makers count.
The formula
Every result above comes from one line:
File size in GB = bitrate in Mbps × duration in seconds ÷ 8 ÷ 1,000
Divide by 8 to turn megabits into megabytes, and by 1,000 to turn megabytes into gigabytes.
Worked example: one hour of ProRes 422 HQ at 1920 x 1080, 23.976 fps. Apple's rate is 176 Mbps. 176 x 3,600 = 633,600 megabits. Divide by 8: 79,200 MB. Divide by 1,000: 79.2 GB. Apple's table prints 79 GB per hour for this format.
A second check: 30 minutes of H.264 at 1080p, 29.97 fps, at YouTube's 8 Mbps. 8 x 1,800 / 8 / 1,000 = 1.8 GB.
Per-hour file size tables for ProRes
Each flavor at common resolutions and frame rates, from Apple's white paper. Per minute is the Mbps figure multiplied by 60 and divided by 8; per hour is Apple's own GB/hr figure.
Before you use these to size a drive, subtract what you are not going to keep. On a finished project, a large share of what is on the disk is never on a timeline, and at ProRes 422 HQ rates that decides how big a drive you buy. Clip Sweeper reads your Premiere and Resolve projects and tells you which of it is which.
1080p, 23.976 fps (1920 x 1080)
| Flavor | Mbps | Per minute | Per hour |
|---|---|---|---|
| ProRes 422 Proxy | 36 | 270 MB | 16 GB |
| ProRes 422 LT | 82 | 615 MB | 37 GB |
| ProRes 422 | 117 | 878 MB | 53 GB |
| ProRes 422 HQ | 176 | 1.3 GB | 79 GB |
| ProRes 4444 | 264 | 2.0 GB | 119 GB |
1080p, 59.94 fps (1920 x 1080)
| Flavor | Mbps | Per minute | Per hour |
|---|---|---|---|
| ProRes 422 Proxy | 91 | 682 MB | 41 GB |
| ProRes 422 LT | 204 | 1.5 GB | 92 GB |
| ProRes 422 | 293 | 2.2 GB | 132 GB |
| ProRes 422 HQ | 440 | 3.3 GB | 198 GB |
| ProRes 4444 | 660 | 5.0 GB | 297 GB |
UHD 4K, 23.976 fps (3840 x 2160)
| Flavor | Mbps | Per minute | Per hour |
|---|---|---|---|
| ProRes 422 Proxy | 145 | 1.1 GB | 65 GB |
| ProRes 422 LT | 328 | 2.5 GB | 148 GB |
| ProRes 422 | 471 | 3.5 GB | 212 GB |
| ProRes 422 HQ | 707 | 5.3 GB | 318 GB |
| ProRes 4444 | 1,061 | 8.0 GB | 477 GB |
UHD 4K, 59.94 fps (3840 x 2160)
| Flavor | Mbps | Per minute | Per hour |
|---|---|---|---|
| ProRes 422 Proxy | 363 | 2.7 GB | 163 GB |
| ProRes 422 LT | 821 | 6.2 GB | 369 GB |
| ProRes 422 | 1,178 | 8.8 GB | 530 GB |
| ProRes 422 HQ | 1,768 | 13.3 GB | 795 GB |
| ProRes 4444 | 2,652 | 19.9 GB | 1,193 GB |
8K, 23.976 fps (8192 x 4320)
| Flavor | Mbps | Per minute | Per hour |
|---|---|---|---|
| ProRes 422 Proxy | 622 | 4.7 GB | 280 GB |
| ProRes 422 LT | 1,400 | 10.5 GB | 630 GB |
| ProRes 422 | 2,011 | 15.1 GB | 905 GB |
| ProRes 422 HQ | 3,017 | 22.6 GB | 1,358 GB |
| ProRes 4444 | 4,525 | 33.9 GB | 2,036 GB |
Frame rate scales the size in proportion: 59.94 fps is 2.5 times 23.976 fps. UHD is about four times 1080p, because it has four times the pixels.
The five ProRes flavors
Apple ships six ProRes flavors for video: four at 4:2:2 and two at 4:4:4. They share a codec family but they are not interchangeable. Rates below are Apple's, at 1920 x 1080 and 29.97 fps.
ProRes 422 Proxy (45 Mbps). The smallest. Made for offline editing and screening copies. Good enough to cut against, not to deliver from.
ProRes 422 LT (102 Mbps). A step up. Used where file size matters more than headroom, such as news and interviews.
ProRes 422 (147 Mbps). The standard finishing codec for online editing, colour and most deliverables.
ProRes 422 HQ (220 Mbps). More headroom for grading and VFX, and for pipelines where you re-render and do not want compression to stack.
ProRes 4444 (330 Mbps, without alpha). Full 4:4:4 colour and an optional alpha channel. Built for compositing, motion graphics with transparency and top-end finishing.
ProRes 4444 XQ (495 Mbps, without alpha) sits above 4444 for the highest-quality masters. ProRes RAW is a different, camera-raw codec and is not in these tables.
The "good enough for what" guide
Picking a flavor is mostly matching the codec to the stage of the job. Too low and you cannot do the work. Too high and you waste storage and render time.
ProRes 422 Proxy. Offline editing. Screening copies for a client on a laptop. Never for finish or grade.
ProRes 422 LT. Deliverables where the spec asks for ProRes but size matters. Talking heads and interviews that will not see heavy colour or VFX.
ProRes 422. The default finishing codec. If you are not sure which to pick, this is usually the right answer.
ProRes 422 HQ. Heavy grading, VFX-bound shots, anything you may re-render several times.
ProRes 4444. Work that needs an alpha channel: composites, mattes, graphics with transparency. Overkill for most live-action delivery.
ProRes vs H.265: when the trade-off tips
Most editors have a choice: keep camera-original H.265 all the way through, or transcode to ProRes for editing.
The size gap is large. At 100 Mbps, an hour of H.265 is 45 GB. The same hour as ProRes 422 HQ in UHD at 23.976 fps is 318 GB, about seven times more. Put your own camera's bitrate into the calculator above to see your ratio.
Recent Apple silicon Macs have hardware H.265 decoding, and many projects cut fine on camera originals. The transcode earns its space for heavy grading, complex multicam, older machines, or a colourist or VFX house that asks for ProRes. If none of those apply, you can often skip it and keep the storage. For a per-codec breakdown of 4K, see the 4K storage breakdown.
Plan the whole project
A project is more than one codec: camera originals, proxies, cache, renders and exports. The storage calculator turns a shoot into a planning number and compares what that costs on each storage provider.
Before you buy more storage
A common pattern: editors transcode everything to ProRes 422 HQ to be safe, then wonder why the drives fill so fast. Often the camera original would have cut fine.
The unused share holds whether you shot ProRes or H.265, which is why clearing the dead weight usually beats agonising over the codec. Clip Sweeper is on the Mac App Store.