512GB memory cards aren’t the largest memory cards available these days–some formats have 1TB and even 2TB sizes–but it’s still a lot of storage space. So you might be wondering whether it’s worth spending a bit more to get the next step up from a 256GB card.
File Size & Video Bitrate
The amount of storage space a video file takes up is determined by what is known as video bitrate. It’s also sometimes known as data rate.
A higher bitrate uses more data to encode each second of video, resulting in less compression, higher potential image quality, and larger file size. Conversely, a lower bitrate uses less data to encode each second of video, resulting in more compression, lower image quality, and smaller file size.
The encoding bitrate is determined by your camera’s capabilities and by the settings you use. High-end cameras can encode 4K video at 400 Mbps or more. Cameras such as action cameras and drones can record 4K video in the 100 Mbps to 200 Mbps range. Lower-level or older cameras, such as early-generation 4K cameras, recorded at closer to 60 Mbps. YouTube recommends a bitrate of between 35 and 68 for 4K videos you upload. 1
Mbps and Mb/s are different ways of writing the same thing. Both refer to megabits per second. They both use a lowercase “b.” Video bitrate is conventionally measured in Mbps.
If the “B” is capitalized, as in MB/s or MBps, it refers to megabytes per second. There are 8 bits in a byte, so there are 8 megabits in a megabyte. The speed of memory cards is conventionally measured in MB/s.
So there’s a wide range of bitrates that can be used to encode 4K video. And that, in turn, means there’s a wide range in answering how much 4K video can fit on a 512GB memory card.
For example, on 512GB, you can fit over 33 hours of 4K footage at a low bitrate of 35 Mbps or nearly 3 hours of 4K footage recorded on a high-end camera at 400 Mbps. So it really depends on the capabilities of your camera and which settings you’re shooting with.
Here’s a table that shows how much 4K video you can fit in 512GB at various bitrates.
4K Video on a 512GB Memory Card Chart
| Video Bitrate (Mb/s) | Duration |
|---|---|
| 35 | 33 hours and 17 minutes |
| 45 | 25 hours and 53 minutes |
| 50 | 23 hours and 18 minutes |
| 60 | 19 hours and 25 minutes |
| 70 | 16 hours and 39 minutes |
| 78 | 14 hours and 56 minutes |
| 80 | 14 hours and 34 minutes |
| 90 | 12 hours and 57 minutes |
| 100 | 11 hours and 39 minutes |
| 120 | 9 hours and 43 minutes |
| 125 | 9 hours and 19 minutes |
| 150 | 7 hours and 46 minutes |
| 175 | 6 hours and 39 minutes |
| 200 | 5 hours and 50 minutes |
| 230 | 5 hours and 4 minutes |
| 250 | 4 hours and 40 minutes |
| 300 | 3 hours and 53 minutes |
| 320 | 3 hours and 38 minutes |
| 400 | 2 hours and 55 minutes |
4K Video on 512GB Memory Card Calculator
Here’s another option if you need a bitrate that’s not in the chart above.
0 minutes of 4K video footage at
a bitrate of 100 Mb/s.
Does Framerate Affect 4K Video File Size?
Sort of.
The storage space required for a video file is not directly affected by its framerate or resolution. Even if a 4K30 video is encoded at 100 Mbps and a 4K60 video is encoded at the same bit rate, the amount of storage space they occupy will be the same. Similarly, a 1080p120 file encoded at 100 Mbps will also occupy the same amount of storage space.
However, these factors do play indirect roles in the amount of storage space required. Higher framerates and resolutions contain more visual information to encode, and higher bitrates can result in better image quality for videos recorded at high framerates. Camera manufacturers often increase the bitrate when the framerate is raised to maintain maximum detail and picture quality. For example, a camera may use a higher bitrate for 1080p240 video than for 1080p30, but this is because of the manufacturer’s decision to record the video at a higher bitrate for maximum detail and picture quality, rather than the framerate directly consuming more data.
The relationship between framerate and storage size is more direct with high-end codecs such as Apple ProRes and Cineform, where the bitrate, or data rate, is designed to increase along with increasing framerate. That’s where it’s easy to get data rates up over 1900 Mbps, and it’s to do with a different approach to encoding. (You can read a much more technical discussion of how framerate increases data rate in the Apple ProRes codecs in this Apple white paper.) It’s even more direct with RAW capture.
With codecs such as H.264 or HEVC (H.265), which are designed as much for sharing video as for recording, there’s more emphasis on the target bitrate and keeping filesize small.
512GB Memory Cards
Here are some fast 512GB memory cards in various form factors.
512GB microSD Cards
- Type: microSDXC
- Video Speed Class: V30
- UHS Speed Class: UHS-I
- Rated read speed: 160 MB/s
- Rated write speed: 120 MB/s
- Type: microSDXC
- Video Speed Class: V30
- UHS Speed Class: UHS-I
- Rated read speed: 160 MB/s
- Rated write speed: 120 MB/s
- Type: microSDXC
- Video Speed Class: V30
- UHS Speed Class: UHS-I
- Rated read speed: 190 MB/s
- Rated write speed: 130 MB/s
512GB SD Cards
- Type: SDXC
- Video Speed Class: V90
- UHS Speed Class: UHS-II
- Rated read speed: 300
- Rated write speed: 250
- Type: SDXC
- Video Speed Class: V30
- UHS Speed Class: UHS-I
- Rated read speed: 200
- Rated write speed: 140
- Type: SDXC
- Video Speed Class: V30
- UHS Speed Class: UHS-I
- Rated read speed: 160
- Rated write speed: 120
- Type: SDXC
- Video Speed Class: V30
- UHS Speed Class: UHS-I
- Rated read speed: 170
- Rated write speed: 90
512GB CFexpress Type B Cards
- Type: CFexpress Type B
- Rated read speed: 1700
- Rated read speed: 1400
- Type: CFexpress Type B
- Rated read speed: 1750
- Rated read speed: 1000
- Type: CFexpress Type B
- Rated read speed: 1730
- Rated read speed: 1540
- Type: CFexpress Type B
- Rated read speed: 1700
- Rated read speed: 800
Memory Card Tools
Here are a few other related tools I’ve put together that can be useful when working with memory cards and data rates.
Converting Mbps to MB/s & X Speed Rating to MB/s
Another related and common calculation that often needs to be done when working with memory cards is converting the convention for measuring video bitrate (Mbps, Mb/s, or megabits per second) to the convention for measuring the speed of memory cards (MBps, MB/s, or megabytes per second).
So I’ve put together a simple calculator for that separately. You can find it here:
- Convert Megabits Per Second to Megabytes Per Second Calculator
- Convert Memory Card X Speed Rating to MB/s
Memory Card Size Calculators
If you’re trying to figure out what size memory card to buy, it can be useful to know how much video footage from the camera you can fit on a card. Here are a few tools that can be useful for that:
- Video Bitrate vs Memory Card Size Calculator
- How Much 4K Video Can 128GB Hold?
- How Much 4K Video Can 256GB Hold?
- How Much 4K Video Can 64GB Hold?
Working with Memory Cards
Here are some related posts for making sense of memory cards and working with them.
- Fastest SD Card Speed Tests. With cameras getting improved 4K, 5K, and even 8K video recording and burst shooting features all the time, some of them need the write speeds that only the fastest SD cards provide. So here’s a roundup of the fastest SD cards based on my independent tests.
- Fastest MicroSD Card Speed Tests. Need a fast microSD card? If you’re shooting 4K, 5K, or 8K video, high-speed burst-mode photos, or some other demanding use, speed matters. These are the results from my independent speed tests of the fastest microSD cards.
- Types of SD Cards Explained. There are several different types of SD cards, as well as multiple speed rating systems and cryptic codes. Here’s a rundown of what the differences are.
- UHS-I vs UHS-II on microSD & SD Cards. Wondering what the difference is between UHS-I and UHS-II with SD and microSD cards? Here’s an explanation.
- What are the A1 and A2 Ratings on SD and microSD Cards? You might have seen new A1 and A2 speed ratings on some of the newer SD and microSD cards. So what do they mean? And when should you take notice of it?
- SD Card Formatter App for Formatting, Wiping & Repairing SD & microSD Cards. Here’s a guide to using the SD Association’s official SD Card Formatter for preparing your SD and microSD cards for use.
- How to Format SD Cards on Mac. Here’s a step-by-step guide for formatting both SD and microSD cards.
- Best Free Data Recovery Software for SD Cards. Here’s a rundown of the best free data recovery software to use if you’ve accidentally deleted photos or videos from your SD card.
- How to Rover Deleted Photos from SD Card: SD Card Recovery Options. All those photos you took have disappeared from the SD card. The good news is that there’s still a good chance you can recover photos from the SD card. Here’s what to do. Includes free and paid SD card recovery options.
- More specifically, YouTube recommends a bitrate of 35-45 Mbps for 4K SDR video for footage recorded at framerates of 24, 25, or 30 fps or from 53-68 Mbps for footage recorded at 48, 50, or 60 fps. For 4K HDR video, they recommend 44-56 Mbps for standard framerates (24, 25, 30) or 66-85 Mbps for high framerates (48, 50, 60).[↩]
Images and product information from Amazon PA-API were last updated on 2023-03-28 at 10:29. Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon Site at the time of purchase will apply to the purchase of this product.
