Use this HDD Video Storage Calculator to estimate how much hard drive space your CCTV, NVR, or DVR system needs. Enter the number of cameras, recording hours, storage days, resolution, frame rate, video quality, scene activity, and compression format to get an estimated storage requirement in GB and TB. It can help you plan your surveillance storage before choosing a hard drive.

How to Use the HDD Video Storage Calculator

Estimating CCTV storage is easier when you know how your cameras will record. Follow these steps to get an approximate hard drive capacity.

Select the number of cameras: Choose the number connected to your NVR or DVR, or enter a custom count.
Choose the storage period: Set how many days you want to keep recordings.
Set recording hours: Select the number of hours each camera records per day. For continuous recording, choose 24 hours.
Select the video format: Choose MJPEG, H.264, H.265, or H.265+ according to your camera or recorder settings.
Choose the resolution: Select the resolution used by your cameras, such as 1080p, 4MP, 5MP, or 4K.
Set video quality and scene activity: Busy scenes and higher-quality settings can increase storage requirements.
Select the frame rate: Choose the frames per second (FPS) used for recording.

The calculator updates the estimated storage automatically. Use the result as a starting point when planning your surveillance hard drive.

HDD Video Storage Calculation Examples

The following examples illustrate how camera count, recording time, and retention days affect storage. They use the calculator's approximate bitrate assumptions and are not universal figures for every CCTV system.

Example 1: Four 1080p cameras

Suppose you have four 1080p cameras recording continuously for 24 hours per day, using H.264 at 15 FPS with medium quality and medium scene activity. If the assumed bitrate is 4 Mbps per camera:

Cameras: 4
Recording time: 24 hours per day
Retention period: 7 days
Estimated storage: about 12.1 TB

A drive's usable capacity may be lower than its advertised capacity, so allow for additional headroom when selecting storage.

Example 2: Eight cameras recording for 15 days

Suppose eight 1080p cameras record for 12 hours per day at the same assumed bitrate of 4 Mbps.

Cameras: 8
Recording time: 12 hours per day
Retention period: 15 days
Estimated storage: about 25.9 TB

Recording for fewer hours each day reduces storage compared with continuous recording, assuming the other settings remain the same.

Example 3: Sixteen cameras recording at 4K

A system with sixteen 4K cameras can need substantially more storage than a similar system using 1080p cameras. Higher resolution generally requires more data, particularly when recording at higher frame rates or quality settings.

For an accurate estimate, select the actual resolution, FPS, video format, recording schedule, and retention period in the calculator. If your recorder provides a configured bitrate for each camera, use that bitrate for a more reliable calculation.

What Affects CCTV Hard Drive Storage?

Several settings influence how much storage a surveillance system uses.

Number of cameras: More cameras generally mean more recorded video and higher storage requirements.
Resolution: 4MP, 5MP, and 4K cameras usually need more storage than 720p or 1080p cameras at comparable settings.
Frame rate: Higher FPS can increase the amount of video data recorded each second.
Recording hours: Continuous 24-hour recording requires more storage than recording for only part of the day.
Retention period: Keeping footage for 30 days requires more space than keeping it for 7 days.
Compression format: H.264 and H.265 can reduce storage compared with less efficient formats. Actual savings depend on the encoder and settings.
Scene activity and video quality: Busy scenes, movement, lighting changes, and higher quality settings can increase bitrate.

How Much HDD Storage Do You Need for CCTV?

The answer depends on your cameras and recording settings. A small system with a few cameras may need considerably less storage than a larger installation with high-resolution cameras recording around the clock.

For the best estimate, check your camera or NVR/DVR manual for the configured average bitrate. Multiply the storage estimate by the number of recording days and cameras, and allow extra capacity for overhead and future expansion. If your recorder uses variable bitrate or motion-based recording, actual storage may differ from a continuous-recording estimate.

Should You Choose H.264, H.265, or H.265+?

H.264 is widely supported and works with many CCTV systems. H.265 can often provide similar visual quality at a lower bitrate, potentially reducing storage requirements. H.265+ is a vendor-specific enhancement available on some surveillance systems; its performance depends on the recorder, camera, scene, and settings.

Before choosing a format, confirm that your cameras and recorder support it. The calculator uses approximate compression factors for planning, so actual results may vary.

How to Calculate Dahua CCTV Recording Storage?

To estimate Dahua CCTV storage, enter the number of cameras, resolution, frame rate, recording hours, and required retention days into the calculator. The result gives you an approximate hard drive capacity for your system.

Frequently Asked Questions

1. How do I calculate HDD storage for CCTV cameras?

Estimate the average bitrate per camera, multiply it by recording hours per day, camera count, and retention days. Convert the resulting data amount into GB or TB. This calculator performs an approximate version of that calculation using your selected settings.

2. How much storage do I need for 4 CCTV cameras?

It depends on resolution, bitrate, FPS, recording hours, and how long you want to keep footage. Four cameras recording continuously at 1080p may need several terabytes for a week or longer. Enter your actual settings above for an estimate.

3. Is H.265 better than H.264 for storage?

H.265 often achieves similar video quality at a lower bitrate, which can reduce storage and network bandwidth. The actual saving depends on the encoder, scene activity, and configuration, and both the camera and recorder must support the format.

4. Does 4K CCTV use more hard drive space?

Generally, yes. 4K cameras capture more image detail than lower-resolution cameras and commonly require higher bitrates. The difference depends on compression, FPS, quality settings, and scene activity.

5. How many days can a CCTV hard drive store?

The retention period depends on the drive's usable capacity and the combined bitrate of all cameras. A larger drive or a lower recording bitrate can allow more days of footage to be stored.

6. Does motion detection reduce storage requirements?

It can. Recording only when motion is detected may reduce the amount of footage saved, depending on how frequently movement occurs. Actual savings vary by location, recording configuration, and the amount of activity in the scene.

7. Does the calculator provide an exact HDD size?

No. It provides an estimate based on typical bitrate assumptions. Actual storage can differ because of camera models, encoder settings, variable bitrate, audio, filesystem overhead, and other recorder-specific factors. Use the configured camera bitrate when available for a more accurate result.

8. Should I add extra capacity to my calculated storage?

Yes. It is sensible to allow some extra capacity for overhead, changing recording requirements, and future expansion. The calculator also shows a suggested capacity with a 20% reserve, but this is a planning allowance rather than a guarantee.

9. Can I use this calculator for Dahua NVR and DVR systems?

Yes. You can use this calculator to estimate storage for Dahua NVR and DVR systems, as well as other CCTV brands. Actual storage needs may vary depending on video settings, compression, and scene activity.

Disclaimer: This calculator is intended for general planning purposes. Actual storage requirements depend on your camera and recorder configuration. Confirm the expected bitrate and usable drive capacity with your equipment manufacturer before purchasing hard drives.

HDD Video Storage Calculator