Video File Size Calculator

Video file size planning before you record or export

This video file size calculator turns a planned duration and encoding rate into a storage estimate. Before recording an event, exporting an edit, or uploading a long program, enter the running time, video bitrate, and audio bitrate to see the estimated space required. The result helps compare memory cards, drives, and cloud allocations before a recording session or export begins. It also makes the trade-off visible: longer videos and higher bitrates consume proportionally more storage.

Video bitrate, compression, and storage use

For a video file-size estimate, bitrate is the amount of video data written each second, normally stated in megabits per second (Mbps). A higher selected bitrate generally preserves more image detail but produces a larger stream. Codec choice and image content affect how much quality a given bitrate can deliver, while this calculator uses the bitrate entered rather than predicting codec efficiency. Compression can make a complex project practical to store and transmit, but excessive compression may introduce visible artifacts. Choose a bitrate suitable for delivery, then use the estimate to budget the resulting storage.

Resolution and frame rate when choosing a video bitrate

Resolution and frame rate influence the video bitrate you may decide to use, not a separate multiplier in this calculator. More pixels or more frames per second can require a higher bitrate to maintain similar visual quality, especially for fast motion or detailed scenes. Once the bitrate is fixed, however, two videos with the same running time have the same estimated video-stream size here regardless of their resolution or frame rate. This distinction is useful when comparing export presets: change the bitrate field to model the storage impact of a higher-quality setting.

Video file-size formula and audio calculation

This video storage calculator converts minutes to seconds, multiplies the video bitrate by that duration, and divides by eight to convert megabits to megabytes. The video-stream relationship is shown below. It separately converts the entered audio bitrate from kilobits per second to megabytes, then adds both stream estimates. The displayed total in GB is the combined megabyte total divided by 1,024. Entering a storage amount also lets the calculator compare that displayed total with the capacity you specify.

Formula: Video Size = (Video Bitrate × Seconds) / 8

Formula: Audio Size = (Audio Bitrate × Seconds) / 8000

Worked example: estimating a 90-minute documentary file

For a 90-minute documentary encoded at 12 Mbps with the default 128 kbps audio setting, the calculator estimates 8,100 MB for video and about 86 MB for audio. Its combined result is about 8,186 MB, shown as roughly 7.99 GB by the calculator. Raising only the video bitrate to 20 Mbps increases the video portion to 13,500 MB, so the combined displayed total rises to roughly 13.27 GB. This is why bitrate is the main control to revisit when a planned export does not fit a chosen card or drive; audio is included, but it is much smaller than the video stream in this example.

Video export settings for different delivery platforms

When estimating video storage for a delivery platform, start with the platform's current encoding guidance and your project’s required quality. Streaming services and social apps may recompress uploads, while local playback or archiving may justify a higher-bitrate master. The table below illustrates video-stream storage only, using the same bitrate conversion as the calculator; it excludes audio, so add your audio estimate for a complete file total. Treat resolution and frame rate as context for selecting a bitrate rather than as direct inputs to the formula.

Managing storage for large video projects

Video storage planning is easier when each recording and export has a realistic size estimate. Keep free capacity beyond the calculated total so a card or drive is not filled exactly to its limit, particularly when recording can vary from the target bitrate. For editing, proxies can reduce the working burden while original camera files remain safely stored. Clear file names, organized folders, and separate space for source media and exports also make it easier to locate the correct version. Use the calculator again when changing duration, video bitrate, or audio settings instead of assuming a previous estimate still applies.

What the video size estimate includes and excludes

This calculator explicitly adds one video stream and one audio stream. Additional audio languages, commentary tracks, subtitles, metadata, and container overhead may increase a finished file beyond that estimate. Audio can be entered as 0 when there is no audio stream, or adjusted to match the intended track bitrate. For productions with multiple audio tracks, calculate their combined audio bitrate before entering it. These additions are usually less influential than the video bitrate, but they matter when capacity is tight.

Video file size limitations and assumptions

This video file size calculator treats the entered video and audio bitrates as constant over the full duration. It does not model variable-bitrate behavior, codec-specific efficiency, additional tracks, or container overhead. Variable bitrate recordings may average above or below a nominal setting depending on the footage, so use the result as a storage-planning estimate and reserve extra capacity when a recording must not run out of space.

Video file-size questions creators ask

Using the video storage estimate in your workflow

A video file-size estimate is most useful before recording, rendering, or committing media to a limited-capacity device. Adjust duration, video bitrate, and audio bitrate to compare versions of the same project, then use the storage check to see whether the displayed total fits the capacity you entered. The calculation cannot choose a quality setting for you, but it clearly shows the storage cost of the setting you choose. Recheck the numbers whenever the edit length or export preset changes to avoid unexpected space shortages.

Sources: The video-stream calculation follows the bitrate unit conversion: bitrate in megabits per second multiplied by duration in seconds, then divided by eight, gives megabytes. The calculator applies the same conversion to the audio stream after converting its entered kilobits-per-second value, and adds the two results. Its displayed GB figure divides the combined MB total by 1,024.