H.265 Storage Calculator
Knowing how much footage your security cameras will produce is an important part of choosing an NVR, hard drive, or other recording system. The H.265 storage calculator estimates video storage based on the average bitrate of each camera, how long the cameras record each day, how many days you want to keep footage, and the number of cameras.
H.265, also called HEVC, compresses video to reduce the amount of data needed to store footage. However, there is no single H.265 bitrate that applies to every security camera. Resolution, frame rate, scene activity, and encoder settings can all affect the amount of storage your recordings use. Use a measured average bitrate when possible, or start with a manufacturer-specified average and adjust your estimate as you learn more about your system.
What the H.265 Storage Calculator does
The H.265 Storage Calculator estimates the space needed to retain recorded video for a specified period. It combines four inputs: the average video bitrate per camera, recording hours per day, retention period, and camera count.
The result, labeled Estimated Storage, is displayed in decimal gigabytes (GB). One decimal GB equals 1,000,000,000 bytes. The estimate assumes that every camera records at the same average bitrate for the same number of hours per day.
This makes the calculator useful for planning a new security camera system or checking whether an existing recording drive is likely to meet your retention goal. For example, you can compare the storage needed for 14 days of footage with the amount needed for 30 days, or see how adding cameras affects the total.
The result covers video data only. It does not include audio, filesystem overhead, redundancy, or changes in bitrate that cause actual footage to use more storage than the average you entered. Round up when selecting drive capacity and allow additional space for the features and overhead your system requires.
How to use the H.265 Storage Calculator
Enter the following details to estimate your recording storage:
- Average video bitrate per camera (Mbps): Enter the average video bitrate for one camera in megabits per second. If your cameras record at different rates, use a representative average and understand that the result will be an approximation. A measured average or a manufacturer-specified average is a useful starting point.
- Recording hours per day: Enter the number of hours each camera records in a typical day. Use 24 for continuous recording. For a schedule that records only during certain hours, enter the total scheduled recording time per day.
- Retention period (days): Enter how many days of recordings you want to keep. A longer retention period requires more storage when the other inputs remain the same.
- Number of cameras: Enter the number of cameras included in the estimate. The calculation applies the same bitrate and daily recording time to each one.
Read the Estimated Storage result in GB. Treat it as a starting point for the video portion of your capacity plan, then consider any audio, recording-system overhead, redundancy, and room for variation before choosing a drive.
For motion-based recording, the recording hours per day can represent an estimated daily average. Actual motion events may vary considerably from one day to another, so an estimate based on a quiet period may not provide enough space during busier periods.
How the H.265 Storage Calculator formula works
The calculation multiplies the average bitrate by the total number of seconds recorded and the number of cameras. It then converts the resulting video data from megabits to decimal gigabytes:
Estimated Storage (GB) = Average video bitrate per camera (Mbps) × 3,600 × Recording hours per day × Retention period (days) × Number of cameras ÷ 8,000
There are 3,600 seconds in an hour. Dividing megabits by 8 converts them to megabytes, and dividing megabytes by 1,000 converts them to decimal gigabytes. Together, those conversions produce the divisor of 8,000.
Worked example: four cameras recording continuously
Assume each of four cameras has an average video bitrate of 4 Mbps, records 24 hours per day, and needs 30 days of retention. The 4 Mbps rate is an illustrative assumption, not a guaranteed rate for an H.265 camera.
4 × 3,600 × 24 × 30 × 4 ÷ 8,000 = 5,184.00 GB
The estimated video storage is therefore 5,184.00 GB, or 5.184 decimal TB. That figure excludes audio, filesystem overhead, redundancy, and bitrate variation. A recording system sized exactly to this video estimate may not provide enough usable space for the full 30 days, so account for those additional needs and round up when choosing capacity.
As another illustrative example, two cameras averaging 8 Mbps each for 12 hours per day over seven days require an estimated 604.80 GB of video storage. This shows how the recording schedule, retention period, and camera count work together with bitrate to determine the result.
Use cases for the H.265 Storage Calculator
Security camera owners can use the estimate at several stages of planning and maintenance:
- Choosing storage for a new NVR: Estimate the video capacity needed for your planned cameras and retention period before selecting a drive or recorder.
- Adding cameras to an existing system: Compare the current camera count with a higher count to see how much additional video storage the proposed cameras could require.
- Comparing retention periods: Change the number of days to understand how keeping footage longer affects storage. With all other inputs unchanged, doubling the retention period doubles the estimated video storage.
- Planning a recording schedule: Compare continuous recording with a shorter daily schedule, using the number of hours the cameras are expected to record.
- Checking encoder settings: Estimate the effect of a different average bitrate after reviewing the camera’s resolution, frame rate, and compression settings.
For a mixed camera system, a single average can provide a rough whole-system estimate. For a more detailed plan, calculate groups of cameras with similar bitrates and recording schedules separately, then add their estimated storage results.
Other factors to consider when calculating Estimated Storage
Bitrate is an average, not a fixed guarantee. With variable bitrate recording, footage from a busy entrance, moving trees, or nighttime scenes may use a different amount of data from footage of a quiet area. Use an average that reflects the conditions you expect over the full retention period.
Resolution and frame rate affect the data a camera produces. Higher resolution or a higher frame rate can require more bitrate to preserve the desired image quality. Compression settings and the amount of movement in a scene also affect the rate. H.265 alone does not determine a camera’s storage needs.
Audio and system overhead require additional capacity. If your cameras record audio, the audio data is outside this estimate. The recording system’s filesystem and other operating requirements also consume space. Check your recorder’s documentation for details relevant to its usable capacity.
Redundancy changes the capacity plan. If your system keeps duplicate data or uses a redundant drive configuration, the raw drive capacity needed can be higher than the video storage result. The exact amount depends on the configuration.
Drive capacity and displayed space may use different units. This calculator reports decimal GB, while a device or operating system may display capacity using binary-based units. Formatting and system requirements can further affect the space available for recordings.
Retention is an estimate based on the inputs. Check the recorder after it has collected footage under normal conditions. Observing actual storage use over time can help you refine the average bitrate and decide whether the system is meeting your retention goal.
H.265 Storage Calculator FAQ
How much storage does an H.265 security camera need per day?
It depends on its average bitrate and recording hours. As an illustrative example, one camera averaging 4 Mbps and recording for 24 hours uses an estimated 43.20 GB per day for video. Actual use varies with camera settings and scene activity, and this figure excludes audio and overhead.
What bitrate should I enter for an H.265 camera?
Enter a measured average video bitrate when one is available. Otherwise, use a manufacturer-specified average that matches your intended camera settings as a starting assumption. Resolution, frame rate, scene activity, and encoder settings can all change the actual average.
Does the calculator include audio or hard drive overhead?
No. The result estimates video data only. Audio, filesystem overhead, redundancy, and bitrate variation are excluded, so include additional capacity for your system’s needs when selecting storage.
Can I use the calculator for cameras with different bitrates?
Yes, but the calculator applies one average bitrate and one daily recording duration to every camera entered. For a more detailed estimate, calculate cameras with similar settings in separate groups and add the results.
Does doubling the number of cameras double storage needs?
In this calculation, yes, provided the average bitrate, recording hours, and retention period stay the same. Doubling the camera count doubles the estimated video storage. Additional system requirements may also affect the drive capacity you need.