SD card sizes are one of the first things to check before buying a memory card. Picking the wrong physical size means the card simply will not fit your device, no matter how fast or large it is. Standard SD cards, microSD cards, and the now-obsolete miniSD each have specific dimensions that determine where they work, while the capacity tier (SDHC, SDXC, SDUC) is entirely separate from the physical size.
This guide covers all three SD card physical formats with their exact dimensions, explains capacity types and speed ratings, and shows you which KingSpec memory card matches your camera, drone, phone, or recording device.
Key Takeaways
- Standard SD card size: 32mm x 24mm x 2.1mm, fits cameras, laptops, and camcorders
- MicroSD card size: 15mm x 11mm x 1mm, fits smartphones, drones, action cameras, and gaming handhelds
- MiniSD (21.5mm x 20mm x 1.4mm) is obsolete and not found in modern devices
- Physical size and storage capacity are separate, an SDXC card can be either standard or microSD
- MicroSD cards work in full-size SD slots using a passive adapter at no speed penalty
- Speed class (V30, V60, V90) determines recording suitability, not physical size
SD Card Sizes: All Three Physical Formats Compared
| Format | Length | Width | Thickness | Weight | Status |
|---|---|---|---|---|---|
| Standard SD | 32mm | 24mm | 2.1mm | ~2g | Current |
| MiniSD | 21.5mm | 20mm | 1.4mm | ~0.8g | Obsolete |
| MicroSD | 15mm | 11mm | 1mm | ~0.25g | Current |
Standard SD Card Dimensions
The full-size SD card at 32mm x 24mm x 2.1mm is the original form factor developed by the SD Association in 1999. It remains the standard for professional cameras, DSLR and mirrorless systems, camcorders, and laptops with a built-in SD slot. The larger surface area makes it easier to handle during fast card swaps on set, and it fits directly into any standard SD slot without adapters.
MicroSD Card Dimensions
At just 15mm x 11mm x 1mm, the microSD card is the smallest and most widely used format today. Smartphones, drones, action cameras (GoPro, DJI), Nintendo Switch, dashcams, and security cameras all use microSD slots. A microSD card inserted into a passive SD adapter (a plastic shell matching full-size SD dimensions) works in any standard SD slot at zero speed penalty. The adapter simply holds the card in position; it adds no signal processing. For a detailed comparison of TF card and microSD naming history, see: TF Card vs Micro SD: Full Comparison Guide.
MiniSD Card Dimensions
MiniSD at 21.5mm x 20mm x 1.4mm was introduced as a middle format for early mobile phones in the mid-2000s. It was replaced by microSD and is now obsolete. No modern devices ship with a miniSD slot, and new miniSD cards are not available from major manufacturers.
SD Card Capacity Types: SDSC, SDHC, SDXC, SDUC
Physical size and storage capacity are completely independent. Both a standard SD and a microSD can be SDXC. What changes is the host device compatibility and file system used.
| Capacity Type | Storage Range | File System | Device Requirement |
|---|---|---|---|
| SDSC | Up to 2GB | FAT12 / FAT16 | Any SD-compatible device |
| SDHC | 4GB to 32GB | FAT32 | SDHC or SDXC compatible device |
| SDXC | 64GB to 2TB | exFAT | SDXC or SDUC compatible device |
| SDUC | 2TB to 128TB | exFAT | SDUC compatible device only |
SDHC cards use FAT32, which caps individual file sizes at 4GB. This means a long 4K recording on an SDHC card will be split into multiple files automatically. SDXC and SDUC use exFAT, which removes the 4GB per-file limit and is essential for continuous 4K or 8K video sessions. Most modern operating systems and devices support exFAT natively; older systems may need a driver update. Always check your device's maximum supported card capacity before purchasing, as some older cameras do not recognize cards above 128GB or 256GB even if the card physically fits.
SD Card Speed Classes and What They Mean
Speed class ratings indicate the minimum sustained write speed of the card. This is separate from physical size and determines whether your card can reliably record video without dropping frames or corrupting data. For a deep-dive on matching speed class to your device, see: SD Card Speed Classes: Which Class Do You Need?
| Speed Class | Min. Write Speed | Interface | Best For |
|---|---|---|---|
| Class 10 / U1 | 10 MB/s | UHS-I | Full HD video, basic photography |
| U3 / V30 | 30 MB/s | UHS-I | 4K video, burst photography, drones |
| V60 | 60 MB/s | UHS-II | 4K high frame rate, 6K video, RAW+video |
| V90 | 90 MB/s | UHS-II | 8K video, high-bitrate professional recording |
An important note: UHS-II cards (V60, V90) require a UHS-II card slot to reach their full rated write speeds. In a UHS-I camera or reader, a V90 card performs identically to a V30 card. Check your camera's specification sheet for UHS-I or UHS-II support before upgrading to V60 or V90.
Which SD Card Size Do You Need? Device Compatibility Guide
| Device Type | Card Size Needed | Recommended Speed |
|---|---|---|
| DSLR and mirrorless camera | Standard SD (32mm x 24mm) | V30 minimum; V60 or V90 for high-bitrate |
| Action camera (GoPro, Insta360) | MicroSD (15mm x 11mm) | U3 / V30 minimum for 4K |
| Drone (DJI Mini, Air, Mavic series) | MicroSD (15mm x 11mm) | U3 / V30 for standard 4K; V60 for Cine editions |
| Smartphone | MicroSD (15mm x 11mm) | U1 or U3; A1/A2 if running apps from card |
| Nintendo Switch | MicroSD (15mm x 11mm) | U1 or U3 sufficient |
| Laptop SD slot | Standard SD (or microSD with adapter) | Any class sufficient for file transfer |
| Dashcam and security camera | MicroSD (15mm x 11mm) | U3 / V30 minimum for 1080p or 4K loop recording |
KingSpec Memory Cards: Matched to Every SD Card Size and Speed Need
KingSpec's Mixage memory card range covers both microSD and full-size SD formats across all key speed classes, from everyday 4K recording to professional 8K workflows. Explore the full SD card collection or find your match below.
- Physical Size: MicroSD (15mm x 11mm x 1mm)
- Read Speed: Up to 175 MB/s
- Write Speed: Up to 110 MB/s
- Speed Class: UHS-I, U3, V30, A2
- Capacity: 64GB, 128GB, 256GB
- Compatible: DJI drones, GoPro, smartphones, Switch
- Warranty: 3 Years
The most versatile microSD card in the KingSpec lineup. V30 minimum write speed handles standard 4K recording without dropped frames on DJI drones, GoPro action cameras, and smartphones. The A2 app performance rating also makes it responsive for running apps directly from the card in Android devices.
- Physical Size: Standard SD (32mm x 24mm x 2.1mm)
- Speed Class: UHS-I, U3, V30
- Capacity: 64GB, 128GB, 256GB, 512GB
- Compatible: DSLR, mirrorless, camcorders, laptops
- File System: exFAT (SDXC)
- Use Case: 4K video, RAW burst photography
- Warranty: 3 Years
The practical standard SD card for photographers and videographers recording 4K at standard bitrates. Fits directly into any DSLR, mirrorless camera, or camcorder with a full-size SD slot. V30 minimum write speed ensures smooth 4K recording without interruption during long event or landscape sessions.
- Physical Size: Standard SD (32mm x 24mm x 2.1mm)
- Speed Class: UHS-II, U3, V60
- Read Speed: Up to 280 MB/s
- Write Speed: Up to 180 MB/s (V60 minimum: 60 MB/s)
- Capacity: 64GB, 128GB, 256GB
- Requires: UHS-II camera slot for full speed
- Warranty: 3 Years
Purpose-built for photographers and videographers with UHS-II camera bodies. The 60 MB/s minimum sustained write handles 4K high frame rate, 6K, and simultaneous RAW plus video recording that overwhelms V30 cards. Backward compatible with UHS-I devices at UHS-I speeds.
- Physical Size: Standard SD (32mm x 24mm x 2.1mm)
- Speed Class: UHS-II, U3, V90
- Read Speed: Up to 300 MB/s
- Write Speed: Up to 260 MB/s (V90 minimum: 90 MB/s)
- Capacity: 64GB, 128GB, 256GB
- Requires: UHS-II camera slot for full speed
- Warranty: 3 Years
The highest-rated SD card in the KingSpec lineup. The 90 MB/s minimum sustained write handles 8K RAW recording, cinema-grade high-bitrate video, and the most demanding professional workflows. Essential for videographers using professional UHS-II mirrorless or cinema camera bodies that require V90-rated media.
Adapter Compatibility: Using MicroSD in a Standard SD Slot
A passive SD adapter converts the physical form of a microSD card to fit a standard SD slot. The adapter contains no chips or processing components; it simply makes electrical contact between the microSD card's pins and the SD slot. Speed performance is not reduced, a V90 microSD card in an SD adapter still performs at V90 speeds in a UHS-II slot.
Key rules for adapter use:
- Always insert the microSD card into the adapter before inserting it into a device
- Remove the adapter from the device before removing the microSD card from the adapter
- The write-protect lock tab on the SD adapter, not the microSD card itself, controls write protection
- Most cameras and card readers ship with a free adapter when buying microSD cards; confirm before purchasing separately
You cannot use a standard SD card in a microSD slot, there is no reverse adapter, and the size difference (32mm vs 15mm length) makes it physically impossible. If your device only has a microSD slot, you must use a microSD card, with or without an adapter for off-device file transfers. To understand the difference between TF card and microSD naming, see: What Is a TF Card: Guide to TransFlash Memory Storage.
Conclusion
SD card sizes are fixed by the physical format, standard SD (32mm x 24mm), microSD (15mm x 11mm), or the obsolete miniSD. The storage capacity (SDHC, SDXC, SDUC) and speed class (V30, V60, V90) are separate specifications layered on top of that physical size. Match your device's slot to the correct physical format first, then choose capacity and speed class based on what you are recording. For everyday 4K use, V30 is sufficient. For demanding UHS-II cameras shooting 6K or 8K, V60 or V90 is required.
KingSpec's Mixage range covers microSD for compact devices and standard SD across V30, V60, and V90 speed classes for professional cameras. For high-capacity internal storage to complement your memory card workflow, explore KingSpec's full range of internal SSDs and portable SSDs.
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Frequently Asked Questions
What are the different SD card sizes?
There are three physical SD card sizes. Standard SD measures 32mm x 24mm x 2.1mm and is used in cameras, camcorders, and laptops. MicroSD measures 15mm x 11mm x 1mm and is used in smartphones, drones, action cameras, and gaming handhelds. MiniSD at 21.5mm x 20mm x 1.4mm was used in early mobile phones but is now obsolete and not found in modern devices. Physical size is separate from storage capacity: a microSD and a standard SD card can both be SDXC with the same amount of storage.
What is the size of a standard SD card?
A standard full-size SD card measures exactly 32mm long, 24mm wide, and 2.1mm thick. It weighs approximately 2 grams. This size fits directly into the SD card slots on DSLR cameras, mirrorless cameras, camcorders, and laptops. No adapter is needed when using a full-size SD card in a full-size SD slot.
What is the size of a microSD card?
A microSD card measures 15mm long, 11mm wide, and 1mm thick. It weighs just 0.25 grams, making it the smallest of all SD formats. This compact size fits smartphones, DJI drones, GoPro action cameras, Nintendo Switch, dashcams, and security cameras. A microSD card can also be used in a standard SD slot by inserting it into a passive SD adapter first.
Can I use a microSD card in a standard SD slot?
Yes. A passive SD adapter (a plastic shell shaped like a standard SD card with a slot that holds the microSD) lets you use any microSD card in a full-size SD slot. The adapter contains no processing components, so it adds no speed penalty. A V90 microSD in an SD adapter performs at full V90 speeds in a UHS-II reader. You cannot do the reverse: a standard SD card is physically too large to fit in a microSD slot.
What is the difference between SDHC, SDXC, and SDUC?
These refer to capacity tiers, not physical sizes. SDHC (4GB to 32GB) uses FAT32 and limits individual file sizes to 4GB. SDXC (64GB to 2TB) uses exFAT and removes the 4GB file limit, making it essential for continuous 4K or 8K video recording. SDUC (2TB to 128TB) is the newest standard for professional applications. Your device must support the correct tier to read higher-capacity cards: an SDHC-only device cannot read SDXC cards even if they physically fit in the slot.
What SD card speed class do I need for 4K video?
For standard 4K recording at typical bitrates (up to around 100 Mbps), U3 or V30 is sufficient. Both guarantee a minimum 30 MB/s sustained write speed. For 4K at high frame rates, 6K, or simultaneous RAW plus video recording on a UHS-II camera, V60 is the safer choice at 60 MB/s minimum. For professional 8K or cinema-grade high-bitrate recording, V90 is required at 90 MB/s minimum. Always check that your camera or drone supports the UHS interface the card requires to reach its rated write class.
