How Many Hours of Video Fit on Each Card Size
Seven card and drive sizes, five data rates, one table. Open a capacity for the full working, every codec and the argument that particular size deserves.
The whole range on one screen
Every figure below is the same division: the capacity in bits divided by the data rate in bits per second. The consumer rates come from the GoPro HERO13 Black capacity chart, which publishes recording times on a 128 GB card and states they can be scaled. ProRes comes from the Apple ProRes white paper. Blackmagic RAW is derived from the compression ratio Blackmagic publishes, and the derivation is set out on the sources page. Nothing here was estimated to fill a cell.
| Capacity | Consumer 4K 30 | Consumer 1080p 30 | 4K at 40 Mbps | ProRes 422 HQ UHD 30p | BRAW 12:1 6K DCI 24 |
|---|---|---|---|---|---|
| 32 GB | 1 h 20 min | 2 h 51 min | 1 h 46 min | 4 min 50 s | 8 min 56 s |
| 64 GB | 2 h 41 min | 5 h 43 min | 3 h 33 min | 9 min 39 s | 17 min 52 s |
| 128 GB | 5 h 22 min | 11 h 27 min | 7 h 6 min | 19 min 18 s | 35 min 43 s |
| 256 GB | 10 h 44 min | 22 h 54 min | 14 h 13 min | 38 min 37 s | 1 h 11 min |
| 512 GB | 21 h 28 min | 1 d 21 h | 1 d 4 h | 1 h 17 min | 2 h 22 min |
| 1 TB | 1 d 17 h | 3 d 17 h | 2 d 7 h | 2 h 30 min | 4 h 39 min |
| 2 TB | 3 d 11 h | 7 d 10 h | 4 d 15 h | 5 h 1 min | 9 h 18 min |
Treat every one of these as an estimate. Variable bitrate, scene complexity and formatting overhead all move the real file, and they move it in the direction that costs you space.
Read your own row, not the headline
The spread across a single row is the reason a single answer to "how many hours fit on a card" does not exist. On the same 128 GB, consumer 1080p runs for most of a working day and ProRes 422 HQ at UHD 30p runs for about twenty minutes. Both are 128 GB. Both are legitimate. The difference is 36 times, and it lives entirely in the codec rather than in the card.
Which is why resolution on its own tells you nothing. A 4K file can be 8 Mbps or it can be 884 Mbps, and the word 4K appears in both. Any page that offers you one number for 4K without asking which camera, which codec and which frame rate is guessing on your behalf. Find the rate your camera actually writes, then read across.
If your format is not in the table
Measure it, because it takes less time than searching for it. Record ten seconds, look at the file size in megabytes, divide by the seconds and multiply by eight. That is your bitrate in Mbps, true for your camera at your settings, and it beats every published average. Put it into the storage and recording time calculator and you have your own row.
What one hour costs
The table above reads the question one way. Here it is the other way round, because on a real job the thing you plan is hours, and what you want to know is how much of the card each hour eats.
| Data rate | Mbps | Per minute | Per hour |
|---|---|---|---|
| Consumer 4K 30 | 53 Mbps | 397.5 MB | 23.85 GB |
| Consumer 1080p 30 | 24.84 Mbps | 186.3 MB | 11.18 GB |
| 4K at 40 Mbps | 40 Mbps | 300 MB | 18 GB |
| ProRes 422 HQ UHD 30p | 884 Mbps | 6.63 GB | 397.8 GB |
| BRAW 12:1 6K DCI 24 | 477.8 Mbps | 3.583 GB | 215 GB |
Why one table can cover every size
Capacity and recording time move together in a straight line. Nothing about a 2 TB card makes it store video more efficiently than a 32 GB one, so doubling the capacity doubles the time at the same rate and there is no correction factor hiding anywhere. That is the whole reason these seven pages can share one method and still each give a genuinely different answer.
What does change with size is the problem you should be planning for, and that is what the individual pages are for. At 32 GB the card is on FAT32 and cannot hold a single file over 4 GB, so a long take arrives in pieces. At 256 GB the card stops being the constraint and the copy becomes it. At 512 GB the failure moves from space to sustained write speed. At a terabyte the drive is usually the only copy of the day until it reaches somewhere with a second drive in it. Same arithmetic, different thing to worry about.
What the label means and what your computer shows
Card and drive makers count a gigabyte as 1,000,000,000 bytes. Windows and most cameras divide the same bytes by 1,073,741,824, which is 1024 cubed, and still write GB on the screen. The honest name for that second unit is the gibibyte. This is why a 128 GB card reads as about 119 GB on a computer and a 1 TB drive reads as about 931. Nothing is missing and no space was lost.
Every figure on this site uses the decimal reading, the one printed on the card, because that is also how Apple and Blackmagic label their own published data rates. Mixing the two units is the single most common way a storage calculation goes wrong by seven percent and nobody notices.
Three limits that have nothing to do with capacity
A card can hold footage it cannot record, and that difference has ended more shooting days than running out of space ever has.
Sustained write speed. Capacity decides how much fits. Write speed decides whether the camera can put it there without dropping a frame. Take the megabytes per minute in the second table, work back to megabytes per second, and check it against the sustained write rating rather than the peak.
Continuous recording. Holding a day of footage and rolling all day without stopping are separate problems. Heat, battery and per clip limits interrupt long takes long before the media fills.
The media is not empty. Every result here assumes the whole capacity is free. A working drive with an operating system, a Resolve database and last month's job on it is not the drive on the label. Read the free space and put that number in instead.
Why the real card runs out early
Fourteen years of directing commercials in Sao Paulo taught me to distrust the theoretical figure, and there are four honest reasons for the gap. Most consumer and mirrorless cameras use variable bitrate, so the number in the manual is a ceiling or an average and a handheld pan across foliage spends everything the encoder has. A freshly formatted card has slightly less room than the raw capacity. The camera stops before the last byte because it needs space to close the file properly. And sidecars, proxies, gyro data and audio all land on the same card as the footage.
That is why the main calculator has a safety margin field and why it starts at zero. Ten percent is a working habit of mine, not a measured constant, and I will not dress one up as the other. Type whatever your own experience says.
Common questions
Does a bigger card record for longer at the same quality?
Yes, and in a straight line. Recording time is the capacity in bits divided by the data rate in bits per second, so at a fixed rate twice the card is twice the time and there is nothing else in the sum. A 256 GB card holds exactly twice what a 128 GB card holds of the same format. What changes as capacity grows is not the arithmetic, it is which problem ends your day: on a small card it is space, on a large one it is usually write speed, heat or the time it takes to copy the thing.
Do these times apply to SD, microSD, CFexpress and an SSD alike?
The times do, exactly. A byte is a byte, so any medium of the same stated capacity holds the same footage and every figure in the table above applies to all of them. What separates the formats is sustained write speed, which decides whether a camera can record to them at all without dropping a frame. That is a different specification, printed in a different place, and the large number on the front of the package is usually the read speed, which is the least useful figure on the box.
Which card size should I buy?
Read across your own row rather than take a recommendation. Find the rate closest to what your camera writes, look at the time, and ask whether it covers the longest stretch you cannot interrupt. Then consider buying two smaller cards instead of one larger one, because a card you have finished with can be copied while the camera keeps rolling on the other, and offloading in parallel with the shoot is the only version of it that does not add time to the day. The exception is the recording that cannot be stopped, where one large card is the right answer.
Why does my card fill up before the number says it should?
Four reasons and they all run against you. Most consumer cameras use variable bitrate, so a detailed scene writes more than the average the manual quotes. Formatting takes a slice. The camera stops before the last byte because it needs room to close the file safely. And sidecars, proxies and thumbnails land on the same card as the footage. Every figure on this site is an estimate for that reason, which is why the main calculator has a safety margin field that starts at zero and asks you rather than deciding for you.