What size SD card does a 4K front only dash cam need?
A 128GB card keeps a full 8-hour driving day from a 4K front only dash cam at a typical 32 Mbps; 32GB covers a 2-hour commute. Buy a high-endurance card and check your camera's maximum supported size.
128GB / high endurance
The 128GB size that holds a full driving day at this setting, in a high-endurance grade built for loop recording.
How big a card for how many hours?
A 4K front only camera writes about 14.4GB per hour at a typical 32 Mbps. Adding a rear camera later would add about 10 Mbps and shorten the loop accordingly.
| Hours to keep | Space needed | Card to buy |
|---|---|---|
| 1 h | 15 GB | 16GB |
| 2 h | 31 GB | 32GB |
| 4 h | 62 GB | 64GB |
| 8 h | 124 GB | 128GB |
| 12 h | 186 GB | 256GB |
| 24 h | 372 GB | 512GB |
How long does each card size last at this setting?
| Card | Loop length |
|---|---|
| 16GB | 1 h 2 min |
| 32GB | 2 h 4 min |
| 64GB | 4 h 8 min |
| 128GB | 8 h 16 min |
| 256GB | 16 h 32 min |
| 512GB | 33 h 4 min |
Cards and 4K front only cameras
Check the camera's maximum supported card size before buying.
SANDISK 32GB High Endurance Video microSDHC Card with Adapter for dash cam and home...32GB / high endurance$22.99Check price on Amazon
SANDISK 32GB MAX Endurance microSDHC Card with Adapter for Home Security Cameras and...32GB / high endurance$35.99Check price on Amazon
Integral 128GB High Endurance microSD Card for CCTV, Dash Cam & Security Cameras, 4K...128GB / high endurance$38.95Check price on Amazon
galphi 4K Dash Cam Front, 5GHz WiFi, 32GB Card Included, Mini Dashcam4K / front only / Wi-Fi$49.98Check price on Amazon
THINKWARE U3000 PRO Dash Cam 4K Front, Sony STARVIS 2, Radar, GPS4K / front only / GPS$479.99Check price on Amazon
Frequently asked questions
Is 128GB enough for a 4K front only dash cam?
128GB holds about 8 h 16 min at this setting. That is more than a full day of driving, so it is plenty for most drivers.
Do I need a high-endurance SD card?
Yes. A dash cam rewrites its whole card every few hours, and ordinary cards are not rated for that. High-endurance cards are built for continuous video and handle windshield heat better. A worn-out card often keeps recording but writes corrupt files, so format it in the camera every few weeks and replace it at the first recording error.
What speed class does a dash cam card need?
Even a three-channel 4K camera writes only a few megabytes per second, so a U3 or V30 card is enough. This setup writes about 4.0 MB per second. Endurance, not speed, is what decides how long a card lasts.