Choose CCTV Retention in Six Steps

1. Define why footage is retained

Start with how late an incident might be discovered. Add a margin to that delay instead of choosing an arbitrary long period.

2. Use average bitrate, not resolution alone

Two cameras at the same resolution can write very different amounts because of frame rate, codec, scene complexity, and quality settings. Read the average Mbps from the camera or NVR.

3. Separate continuous and motion recording

Motion savings vary with traffic, trees, rain, and sensitivity. Calculate continuous recording first, then measure a representative week.

4. Leave operating headroom

Allow roughly 10–20% for bitrate spikes, indexes, and formatting differences. This is planning margin, not a universal guarantee.

5. Correct the estimate with measured growth

Record storage growth over seven days, calculate the daily average, and multiply by the target retention. Include nights and bad weather when they matter.

6. Plan how to preserve an incident

Important footage should be exported promptly to another device. A rolling NVR volume can overwrite the event you intended to keep.

Real-world scenario

Two entrance cameras may benefit from motion recording, while a perimeter view containing traffic and trees can behave almost like continuous recording. Measure seven-day growth per channel instead of applying one saving percentage everywhere.

Action checklist

• Maximum delay before an incident is discovered
• Average Mbps for each channel
• Seven-day sample including nights and weather
• Procedure to export important footage immediately

Frequently asked questions

Is 30 days enough?

Choose retention from the real discovery delay for deliveries, parking, or other incidents, then add margin.

Should I reduce frame rate?

First confirm the motion detail needed for the evidence purpose.