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How long does a dash cam record?
Updated
A dash cam records the whole time the car is on. It never stops because the card is full. It loops, which means it records over the oldest video. So the real question is how far back you can go. With a 128GB card and a 2K front and rear setup, that is about 9.5 hours of driving.
Hours before it loops
This table uses the same typical bitrates as the card calculator. Your camera's real numbers will differ a little with its quality setting.
| Card | 1080p front only | 2K front + rear | 4K front + rear | 4K front + rear + cabin |
|---|---|---|---|---|
| 32GB | 5.9 | 2.4 | 1.8 | 1.4 |
| 64GB | 11.9 | 4.7 | 3.6 | 2.8 |
| 128GB | 23.7 | 9.5 | 7.1 | 5.7 |
| 256GB | 47.4 | 19.0 | 14.2 | 11.4 |
| 512GB | 94.8 | 37.9 | 28.4 | 22.8 |
The math: card size in GB, times 8000, divided by the total bitrate in Mbps, divided by 3600.
How many hours do you need?
Think about how long it could take you to notice a problem. A crash, you know right away. A scrape in a parking lot or a complaint from a rideshare passenger might come up days later. If you drive an hour a day and want a week of history, you need about 7 hours. A 128GB card covers that on a 2K or 4K front and rear camera. A three-camera setup needs 256GB to do the same.
Locked clips do not loop
When the G-sensor feels a hit, or you press the lock button, the camera protects that clip from being recorded over. That is what you want after a crash. The catch: if the sensor is set too high, every pothole locks a clip. Locked clips pile up and shrink the space left for normal looping. Set the G-sensor to low or medium, and format the card in the camera every month or two to clear them out. Save anything you need first.
Does it record when the car is off?
Only with parking mode, and that needs a hardwire kit. See the parking mode guide. Parking video shares the same card, so long parking sessions shorten how far back your driving video goes. Low bitrate and time lapse parking modes use much less space.
With the cameras on this site
- VIOFO A229 Plus: 2K front and rear, and the listing shows support for cards up to 512GB. That is about 37.9 hours. Caveat: the card is sold separately on most bundles.
- ROVE R2-4K Dual: comes with 128GB, about 7.1 hours at its 4K front and rear setting. The maker says it supports cards up to 1TB. Caveat: its 4K is upscaled, so the bigger files do not buy you more detail.
- REDTIGER F17: three cameras on the 64GB card in the box is about 2.8 hours. Caveat: plan on a bigger card from day one.
How long the camera itself lasts is a different question. The card usually goes first. Buy a high endurance card and replace it every couple of years. All four cameras are compared on the shortlist page.