How Long Do Security Cameras Keep Footage? Retention, Storage and Overwriting
You discover damage to a parked car on Monday and open the camera app to check Saturday night. The live view works, yesterday is available, but Saturday has disappeared. That can be normal storage behavior rather than a camera fault: the system may already have replaced the oldest recordings.
Security cameras do not have one standard retention period. Cloud history follows the service and settings you use; local memory cards and recorders usually retain as much video as their available capacity and recording policy allow. A quoted 30-day history can also mean selected event clips, not a continuous recording of the entire month.
The useful question is therefore how far back your saved timeline reaches under normal conditions. This guide shows how to check it, estimate local retention and preserve something important before it disappears.
Where the recording is stored determines the first answer
| Storage arrangement | What normally limits history | What to check |
|---|---|---|
| Camera microSD card | Usable capacity, bitrate, recording hours and overwrite settings | The oldest playable date, supported card capacity and whether loop recording is enabled |
| NVR or DVR hard drive | Shared drive capacity, all recorded streams, quotas and retention settings | Each camera’s allocation and recording schedule, not just total disk size |
| Cloud event history | Subscription entitlement, selected retention and service conditions | Whether the plan includes actual clips, their expiry and the effect of cancellation |
| Cloud continuous history | Eligible hardware, plan and a specific continuous-video period | Whether continuous history is shorter than event history |
| Downloaded incident copy | Your own storage and deletion process | Whether the original file is genuinely downloaded and backed up |
A camera can use more than one arrangement. Its local card might contain continuous video while the cloud has only events. Searching one library does not establish what exists in the other. Our local-versus-cloud comparison explains those architectures and their costs.
Do cameras usually keep 7, 30 or 90 days?
You will encounter all of those figures, but none is a dependable default across home cameras. A small card recording a high-bitrate stream continuously can fill in a few days. A quiet event-only camera can retain a much longer calendar period on the same capacity because it saves fewer hours of actual video.
Published manufacturer ranges need the same care. Ring’s storage-time guidance describes configurable cloud event history up to 180 days and warns that other features can have shorter periods. It also says changes apply to future recordings and do not recover history already lost. That is a service-specific example, not a promise about every camera or region.
Google distinguishes event and continuous history for its supported cameras and services. Before comparing subscription prices, write down which history type you actually need. Sixty days of event clips and ten days of continuous footage are different resources, even when both appear in one plan description.
Calculate local recording retention
For a steady stream, the starting arithmetic is straightforward. One megabit per second recorded for a full day produces approximately 10.8 decimal gigabytes of video. Multiply by the combined bitrate of every stream being stored, then compare with the usable recording capacity.
Daily video in GB ≈ total recorded bitrate in Mbps × 10.8. Retention in days ≈ usable recording capacity in GB ÷ daily video in GB.
This simplified estimate assumes continuous recording and decimal units. Add audio, additional streams and other stored data where relevant, and allow for filesystem overhead and variable bitrate. It is a planning calculation, not a guaranteed retention claim.
Suppose four cameras each average 4 Mbps. The combined 16 Mbps stream produces about 172.8 GB per day. A recording area with 4,000 GB actually available would theoretically hold about 23.1 days at that rate. A nominal 4 TB disk will provide less than that full figure for video, so the practical result will be shorter.
Our camera data and storage calculator lets you change camera count, bitrate and recording time. Use an observed average where the recorder provides one; a maximum-bitrate setting can be useful for a conservative estimate but is not necessarily the stream’s average.
What does a 64 GB, 128 GB or 256 GB card hold?
The following figures are arithmetic examples for one camera continuously recording at a constant 2 Mbps. They assume the stated capacity is available to video and exclude overhead, so they are not promises for a particular card or camera.
| Illustrative available capacity | Daily video | Theoretical retention |
|---|---|---|
| 64 GB | 21.6 GB | About 3.0 days |
| 128 GB | 21.6 GB | About 5.9 days |
| 256 GB | 21.6 GB | About 11.9 days |
| 512 GB | 21.6 GB | About 23.7 days |
At 4 Mbps, those durations approximately halve. At 1 Mbps, they approximately double. Resolution does not fix the bitrate: two cameras with the same pixel dimensions can record different amounts of data because of compression, frame rate and scene activity.
A larger card also has to be compatible. Check the exact hardware revision and supported capacity rather than inserting the biggest card you can find. Our microSD buying guide separates capacity from endurance and compatibility.
Event recording changes the calculation
If a camera records only two hours of events each day at the same average bitrate, it stores roughly one-twelfth of the video produced by 24-hour recording. That can extend the calendar history substantially. It also means there is no continuous record of the other 22 hours.
Do not assume tomorrow will contain the same amount of motion. Traffic, delivery activity, rain or a branch in view can generate extra clips. Pre-event buffers and post-event recording also add saved time beyond the instant when motion was first detected.
For a realistic estimate, observe several representative days and count recorded duration or storage consumed. Include a busy day rather than using only a quiet Sunday. The continuous-versus-motion guide explains when the storage saving is worth the missing intervals.
Loop recording, storage full and automatic deletion
With supported loop recording enabled, a system normally makes space by replacing its oldest footage. A full recording disk can therefore be healthy: the useful question is whether new footage is being saved and the timeline is advancing normally.
When overwrite is disabled, some devices stop saving new material when their assigned storage fills. Other systems also allow an explicit maximum age, per-camera quota or protected-file allocation. Those settings can reduce history even when the overall disk appears to have space.
Reolink’s card guidance confirms that its supported loop-recording arrangement does not require routine manual formatting when overwrite is enabled. Treat repeated formatting as troubleshooting with data-loss consequences, not normal housekeeping.
Check the actual oldest recording
Open playback for the correct camera and storage destination. Clear person-only or vehicle-only filters, select an older date and attempt to play a real segment. A calendar marker or notification thumbnail is not enough: verify that the video itself starts and contains the expected scene.
Record the oldest playable time and repeat the check a few days later. If the system has reached a stable rolling window, you will see approximately how much history it retains under that workload. A newly installed empty drive has not yet demonstrated its full retention cycle.
Check each channel on a recorder. Different schedules, quotas and stream settings can produce different histories. Also verify time zone and clock settings before interpreting an apparently missing day; the timestamp guide covers this source of confusion.
How to extend useful history without ruining the footage
Start by confirming that storage is healthy, fully available to the intended channels and appropriately sized. Remove unnecessary duplicate streams only when you understand their role. A supported capacity upgrade can preserve image quality while extending retention.
Next assess recording mode and schedule. Continuous recording may be justified at one entrance while event recording is adequate elsewhere. Do not disable nighttime recording merely to make the storage figure look better when nighttime is the period you most need.
Finally test quality changes against the actual task. Reducing bitrate or frame rate can save storage, but a longer archive of unreadable faces is not necessarily an improvement. Export a moving-subject sample before and after the change and retain the setting that still answers your security question.
How long should you keep footage legally?
Technical capacity and an appropriate retention policy are separate decisions. There is no universal rule that every home or business must keep exactly 30 days. Applicable requirements depend on jurisdiction, purpose and sometimes the sector or circumstances.
For example, the UK ICO’s surveillance guidance ties retention to the purpose and says available storage alone does not justify keeping data longer. This is a UK regulatory example, not a global legal instruction. Check local requirements for your actual use, particularly workplace or shared-space recording.
A specific incident may require preserving relevant material separately from routine rolling footage. Follow the applicable reporting, investigation and preservation instructions; do not allow ordinary automatic deletion to erase a clip you already know must be retained.
Save important footage before changing the system
Download an original clip with enough context before and after the event, then test that it plays independently of the app. Keep a protected second copy when the material matters. A share link pointing back to an expiring cloud event is not the same as owning a downloaded file.
Export before formatting, replacing storage, removing a camera from its account or canceling a service. Different platforms handle those actions differently, and increasing retention later cannot recreate footage that is already gone. Use the export guide and backup guide to establish the process.
Questions readers commonly ask
Can I get footage from six months ago?
Only if the required material still exists in the system or a separate preserved copy. Check downloads, authorized backups and other recording destinations; an old event notification does not prove the original video remains available.
Does changing to a larger cloud plan recover old clips?
Do not assume so. Verify the service’s rules, but longer future retention is not a recovery mechanism for deleted or expired history. Our recovery guide distinguishes these cases.
Does switching off the camera stop old footage being deleted?
Not reliably across storage systems. Cloud retention can continue to expire independently, while local behavior depends on the recorder. Preserve the relevant files rather than treating power loss as a universal retention control.
The practical answer: measure the oldest playable footage, understand which settings control it and export incidents promptly. A storage specification is a starting estimate; your verified recording history is the useful result.
