Before you hit record on a long shoot, it helps to know exactly how much runway you have. But figuring out how much 4K video fits on a memory card isn’t a simple, static number. It is entirely dictated by your camera’s video bitrate.
2026 Update: With modern mirrorless cameras pushing heavy 10-bit 4K and 8K video, 128GB has quickly become the bare minimum storage capacity for video shooters. But SD memory cards are now available up to 2TB. Here’s how to calculate your recording times to see what size memory card you need.
A higher bitrate uses more data to encode each second of video, resulting in less compression, higher potential image quality, and a larger file size. Conversely, a lower bitrate applies more compression, resulting in lower image quality and a smaller file size.
Your encoding bitrate is determined by your camera’s hardware and the specific recording menu settings you choose. High-end cameras like the Nikon Z8 can encode heavy 4K or 8K video at 400 Mb/s or more. Action cameras and drones typically record 4K in the 100 Mb/s to 200 Mb/s range. Meanwhile, YouTube officially recommends a much lighter bitrate of between 35 and 68 Mb/s for uploaded 4K videos.
Mbps vs. MB/s: The Capitalization Trap
Mbps and Mb/s are different ways of writing the same thing: megabits per second (lowercase “b”). Camera video bitrates are conventionally measured in Mb/s.
If the “B” is capitalized, as in MB/s or MBps, it refers to megabytes per second. There are 8 bits in a single byte. The read/write speeds of physical memory cards are conventionally measured in MB/s.
Want to convert from one to the other? Use my Mbps vs MB/s interactive calculator.
Related: to convert a camera’s video bitrate (Mbps) into the card write speed it needs (MB/s), use my Mbps to MB/s converter.
4K Video Capacity Calculator
Because of this massive variance in bitrates, a 128GB memory card could hold anywhere from 8 hours to under an hour of 4K footage. To remove the friction of guessing your remaining card space in the field, I put together this simple calculator to find your exact recording time.
Real bitrates vary by mode, frame rate, and scene — presets are typical values as of July 2026. Card sizes use decimal GB (1 GB = 1000 MB), matching how manufacturers rate capacity; formatted capacity is slightly less.
Notes on the Calculator Results
- The “Up To” Caveat: This calculates the raw capacity of the primary video file. However, your camera often writes extra data to the card. For instance, many cameras simultaneously save a low-bitrate proxy video file alongside the main footage for mobile app transfers. While small, proxies eat into your total capacity. The actual recording time will also be reduced by any existing photos, formatting directories, or firmware files on the card.
- The Gigabyte vs Gibibyte Gap: Memory card manufacturers rate capacity using decimal gigabytes (1GB = 1,000MB). Windows reports storage in binary gibibytes (1GiB = 1,024MiB), which is why a “256GB” card shows up as ~238GB when you plug it into a Windows PC. (Macs have reported decimal gigabytes since 2009, so the label and the readout match.) This calculator uses the decimal convention to match the physical label printed on your memory card.
- Variable Bitrate (VBR): Most hybrid cameras compress video on the fly using a Variable Bitrate. The processor dynamically adjusts the data rate based on scene complexity. Over a long take, it usually averages out close to the camera’s stated target bitrate, but highly detailed scenes with rapid motion will create larger files and slightly reduce your total recording time.
Storage Capacity Reference Charts
If you prefer a quick visual reference, here is exactly how much 4K video you can fit on common memory card sizes at standard industry bitrates.
| Card Size | 100 Mbps (Standard 4K) | 200 Mbps (High-Bitrate) | 400 Mbps (Cinema 4K) |
|---|---|---|---|
| 32 GB | ~43 mins | ~21 mins | ~11 mins |
| 64 GB | ~1 hr 25 mins | ~43 mins | ~21 mins |
| 128 GB | ~2 hrs 51 mins | ~1 hr 25 mins | ~43 mins |
| 256 GB | ~5 hrs 41 mins | ~2 hrs 51 mins | ~1 hr 25 mins |
| 320 GB* | ~7 hrs 7 mins | ~3 hrs 33 mins | ~1 hr 47 mins |
| 512 GB | ~11 hrs 23 mins | ~5 hrs 41 mins | ~2 hrs 51 mins |
| 1 TB | ~22 hrs 13 mins | ~11 hrs 7 mins | ~5 hrs 33 mins |
| 2 TB | ~44 hrs 27 mins | ~22 hrs 13 mins | ~11 hrs 7 mins |
*320GB is a common capacity for CFexpress Type A cards, not standard SD cards.
Common Bitrates by Camera Type
| Camera Type | Popular Models | Common Bitrates |
|---|---|---|
| Mirrorless | Sony a7 IV, Canon EOS R6 II | 100 – 200 Mbps |
| Cinema | Sony FX3, Canon R5 C | 400 – 810 Mbps |
| Action & Drone | GoPro Hero 13, DJI Air 3 | 100 – 150 Mbps |
| Smartphone | iPhone 17 Pro, Galaxy S26 | 35 – 75 Mbps |
| 8K Mirrorless | Nikon Z8, Canon R5 II | 200 – 5,800 Mbps |
Memory Card Buying Advice
It’s common for videographers to overspend on memory cards. If your camera only shoots standard 100 Mbps 4K video, it only requires a sustained physical write speed of 12.5 MB/s. Buying a top-tier V90 SD card that writes at 250 MB/s will not make your in-camera recording quality any better — it just burns cash.
What you want is a memory card that’s fast enough. Fast enough that all your camera’s features work reliably, but not too fast to the point where you’re paying for superfast cards that your camera can’t make best use of. So you want to match your card’s Speed Class to your camera’s actual bitrate limit. A reliable V30 card is perfectly fine for 100 Mbps codecs. Reserve the expensive V60, V90, and CFexpress cards for heavy 400+ Mbps intra-frame or RAW video formats.
Recommended 128GB Video Cards
If your calculation shows you need more space, these are the most reliable 128GB cards in my kit right now based on sustained field performance.
- For Standard 4K (100-200 Mbps): SanDisk 128GB Extreme PRO SDXC UHS-I. The V30 rating offers a perfect balance of price and stability for standard mirrorless and drone codecs.
- For Heavy 4K (Up to 400 Mbps): Lexar Professional 1800x Gold 128GB SDXC UHS-II. A V60-rated card that acts as the professional standard for high-bitrate 4K 60fps without the massive V90 price markup.
- For Cinema & RAW 4K: SanDisk 128GB Extreme PRO CFexpress Type B. Essential for handling extreme data rates on flagship bodies like the Z8 or EOS R5.
A quick workflow note: No matter which card you buy, remember the golden rule of data management. Always format the card inside the camera before every shoot, rather than just deleting clips on your computer. It rebuilds the file directory properly and prevents fragmentation errors when the data rate spikes.
Pro Video Storage FAQ
Does 4K 60fps take up more space than 4K 30fps?
Indirectly, yes.
Resolution and framerate don’t play a direct mathematical role in how much storage space a file takes up; only the bitrate matters. For instance, 4K30 video encoded at 100 Mbps will take up the exact same amount of physical storage space as 4K60 video encoded at 100 Mbps.
However, if you cram 60 frames into the same 100 Mbps data limit as 30 frames, each individual frame receives less data, reducing the image quality. To preserve visual fidelity, camera manufacturers usually force the processor to use a much higher bitrate when you select a faster framerate, which in turn results in larger files.
The relationship between framerate and file size is much more direct with high-end codecs like Apple ProRes and Cineform. In those formats, the data rate is designed to scale dynamically alongside the framerate. You can read a highly technical discussion of how framerate scales data limits in this Apple ProRes white paper.
How many GB is 1 hour of 4K video?
For standard 4K video recorded at 100 Mbps, one hour of footage will take up approximately 45GB of space. If you are shooting at a cinema-grade 400 Mbps, that same hour will jump to 180GB.
What is the best bitrate for 4K YouTube uploads?
YouTube officially recommends an upload bitrate of 35–45 Mbps for standard 4K SDR (24, 25, or 30 fps) and 53–68 Mbps for high frame rates (48, 50, or 60 fps).
Recording at a higher bitrate in-camera gives you more flexibility and cleaner data for color grading during post-processing, but the final exported file will be heavily compressed by YouTube’s servers anyway.
