Video Frames Per Second Storage Calculator
The Video Frames Per Second Storage Calculator estimates how much storage a dashcam recording may need when you know its bitrate at a reference frame rate. Enter the recording duration and your chosen frame rate, then add an optional allowance for extra storage. The result is an estimate in decimal gigabytes (GB), useful for planning memory card capacity or archived footage.
What the Video Frames Per Second Storage Calculator does
This video frames per second storage calculator starts with a known video bitrate and estimates how that bitrate changes at a different frame rate. It then calculates the storage needed for the recording time you enter. If you want extra room for audio, file overhead, or other files, you can add a percentage allowance.
For example, a dashcam recording at 20 Mbps and 30 fps would use an estimated 9.00 GB for one hour when no allowance is added. Those numbers are illustrative assumptions, not a tested rate for a particular camera.
The estimate relies on one key assumption: bitrate scales proportionally with frame rate. Under that assumption, changing from 30 fps to 60 fps doubles the estimated bitrate if the reference bitrate and other conditions stay comparable. Actual compressed footage may behave differently, especially when a dashcam uses variable bitrate.
The calculator is most useful when you have a bitrate from your dashcam’s specifications, settings, or an existing recording at a known frame rate. It does not determine the bitrate from resolution or select a memory card for you.
How to use the Video Frames Per Second Storage Calculator
Gather a reference bitrate and frame rate for your dashcam, decide how long you want to record, and enter the following values:
- Bitrate at reference frame rate (Mbps): Enter the video bitrate in megabits per second. Use a value associated with the reference frame rate you enter next.
- Reference frame rate (fps): Enter the frames per second at which the reference bitrate applies. For instance, enter 30 if your known bitrate is for 30 fps footage.
- Recording frame rate (fps): Enter the frame rate you want to estimate, such as 30 or 60 fps.
- Recording duration (hours): Enter the total recording time in hours. You can use a decimal for a partial hour; for example, 1.5 represents one hour and 30 minutes.
- Additional storage allowance (%): Enter a percentage to add extra space to the calculated video estimate. Enter 0 if you do not want to add an allowance.
Read the Estimated Storage result in GB. The calculator displays the result to two decimal places. Its default values are 20 Mbps, 30 fps for both frame rate fields, one hour of recording, and a 0% allowance. These defaults produce an estimate of 9.00 GB.
To compare two recording settings, change the recording frame rate while keeping the other inputs the same. Remember that the comparison reflects the proportional bitrate assumption; it is not a measurement of how your particular dashcam encodes video.
How the Video Frames Per Second Storage Calculator formula works
The formula first adjusts the reference bitrate by the ratio of the recording frame rate to the reference frame rate. It then multiplies the adjusted bitrate by the duration in seconds, converts the result to decimal GB, and applies the storage allowance.
Estimated Storage (GB) = reference bitrate × recording frame rate ÷ reference frame rate × recording hours × 3,600 ÷ 8,000 × (1 + allowance percentage ÷ 100)
The factor of 3,600 converts hours to seconds. Dividing by 8,000 converts decimal megabits to decimal gigabytes: eight bits make one byte, and 1 GB equals one billion bytes.
Worked example: 60 fps with an allowance
Assume a dashcam has a reference video bitrate of 20 Mbps at 30 fps. You want to estimate two hours at 60 fps and add a 10% storage allowance. These sample rates are assumptions for the example; actual dashcam footage may use a different bitrate.
- Scale the bitrate: 20 Mbps × 60 ÷ 30 = 40 Mbps.
- Convert two hours to seconds: 2 × 3,600 = 7,200 seconds.
- Calculate video storage: 40 × 7,200 ÷ 8,000 = 36 GB.
- Add the 10% allowance: 36 × 1.10 = 39.60 GB.
The estimated result is 39.60 GB. The allowance adds 3.60 GB to the calculated video storage. It is a buffer you choose, not a separate measurement of audio or file overhead.
Use cases for the Video Frames Per Second Storage Calculator
Planning a long drive: Estimate the space needed for the hours you expect to record. If your trip includes several driving periods, add their durations before entering the total.
Comparing frame rates: Use the same reference bitrate to compare estimated storage at different recording frame rates. The calculation helps illustrate how the assumed bitrate increase affects capacity over the same duration.
Estimating archived footage: If you save dashcam clips to a computer or external drive, calculate an approximate amount of storage for the total hours you plan to keep. Add an allowance if you also need room for associated files.
Planning around loop recording: Dashcams may overwrite older footage when a card fills. An estimate can help you consider how much recording time might fit, although actual retention depends on the camera’s settings, card capacity, protected clips, and real recording bitrate.
Comparing recording durations: Keep the bitrate and frame rates unchanged and try different durations. Under the calculator’s assumptions, doubling recording time doubles the estimated storage before and after the same percentage allowance.
Other factors to consider when calculating Estimated Storage
Variable bitrate and scene complexity: Some cameras change bitrate as footage changes. Movement, lighting, weather, and scene detail can affect compression. A proportional frame-rate estimate may therefore differ from the size of the files your camera actually produces.
Resolution, codec, and quality settings: The reference bitrate is most useful when these settings remain comparable to the recording you want to estimate. Changing them can alter storage needs independently of frame rate. Use a reference bitrate that matches your intended settings as closely as possible.
Audio and overhead: The formula starts with the video bitrate you enter. Audio, file-system overhead, and other files are included only to the extent that your additional storage allowance covers them. The calculator does not calculate those items separately.
Multiple camera channels: A front and rear dashcam may produce separate video streams with different bitrates. Estimate each stream using its own reference information and add the results for a combined estimate. Account for any shared overhead when choosing your allowance.
Decimal GB and available capacity: The result uses decimal GB, where 1 GB is one billion bytes. A device or operating system may display capacity differently, and some card space may already be occupied or unavailable for footage. Check the space available on the device you plan to use.
For a more practical estimate, compare the calculator’s result with the size of footage recorded by your own dashcam under the settings you intend to use. Real recording conditions and camera behavior can cause actual storage use to be higher or lower.
Frequently asked questions
Does doubling the frame rate always double dashcam storage?
No. The calculator assumes bitrate doubles when frame rate doubles, with other conditions comparable. A camera’s compression and bitrate settings may produce a different result, particularly with variable-bitrate recording.
What bitrate should I enter?
Enter a known video bitrate in Mbps that corresponds to the reference frame rate. A value from your camera’s specifications or an existing recording can provide a starting point. Make sure the resolution, codec, and quality settings are as comparable as possible to your planned recording.
How much storage does one hour at 20 Mbps use?
At the same reference and recording frame rate, one hour at 20 Mbps uses an estimated 9.00 GB with a 0% allowance. This is a calculation based on the entered bitrate, not a guarantee of the size of a particular recording.
What does the additional storage allowance cover?
It adds the percentage you enter to the calculated video storage estimate. You can use it as a buffer for audio, file overhead, or other files, but those items are not measured separately. Choose an allowance that suits your situation and check actual footage sizes when possible.
Can I use the result to predict exactly when my memory card will fill?
The result is an estimate, so it cannot predict the exact fill time. Actual bitrate, audio, existing files, protected clips, available capacity, and loop-recording behavior can all affect how much footage a card holds.