What this Mix Export File Size Calculator does
The Mix Export File Size Calculator estimates the storage used by an uncompressed pulse-code modulation (PCM) audio export. It uses four settings: duration, sample rate, bit depth, and channel count. The result is expressed in decimal gigabytes, where one GB equals 1,000,000,000 bytes. This gives you a practical planning estimate before you render a mix or transfer a large session.
The estimate describes audio sample data. It does not add a file header, metadata, embedded artwork, broadcast wave information, or other container overhead. It also does not predict the size of MP3, AAC, FLAC, or another compressed format. Lossless compression depends on the material and encoder, while lossy formats depend on settings such as bitrate. Those need a different calculation or a test export.
For a straightforward stereo PCM render, each moment contains one sample for the left channel and one for the right. Increasing duration adds more samples. Increasing sample rate packs more samples into each second, and increasing bit depth uses more bits for every sample. More channels multiply the data in the same way.
How to use the Mix Export File Size Calculator
Enter the planned duration in minutes, then choose the sample rate and bit depth that match the export settings in your digital audio workstation. Select the number of channels in the rendered file. Stereo is two channels, even if the session contains many tracks. A stem export may be mono or stereo depending on how it is configured.
- Set the duration to the length of the rendered audio, including any tail you intend to preserve.
- Choose the sample rate that the export will use, such as 44.1 or 48 kHz.
- Choose the bit depth configured in the export dialog.
- Select the channel count for the final file, then read the estimated size in decimal GB.
For example, consider a four-minute stereo mix exported at 48 kHz and 24-bit. The calculation is 4 minutes × 60 seconds per minute × 48,000 samples per second × 24 bits per sample ÷ 8 bits per byte × 2 channels. That equals 69,120,000 bytes, or 0.06912 decimal GB. The calculator displays the result rounded to three decimal places, so it shows about 0.069 GB.
How the Mix Export File Size Calculator formula works
The formula first converts minutes into seconds by multiplying the duration by 60. It then multiplies seconds by samples per second to find the number of samples in one channel. Bit depth divided by eight converts bits per sample into bytes per sample. Multiplying by the channel count accounts for each channel, and dividing by one billion converts bytes into decimal gigabytes.
In compact form, the model is duration in seconds × sample rate × bytes per sample × channels ÷ 1,000,000,000. For 24-bit audio, each sample uses three bytes in the model. For 16-bit audio, it uses two. The calculator treats the chosen bit depth as the stored sample width. This is appropriate for common PCM export planning, while some application formats may package sample data differently.
The result is an estimate of uncompressed sample data. It does not include extra file structure or padding, and rounding means the displayed figure may not match a file browser byte for byte. A 32-bit integer selection is included for PCM workflows that explicitly use that format. Floating-point exports can have format-specific storage behavior, so check the DAW documentation when exact file size matters.
Use cases for the Mix Export File Size Calculator
Estimating size is useful during production planning, especially when a project has many versions or a fixed transfer limit. A rough figure can help you anticipate whether a render fits on a portable drive, in a shared folder, or within a delivery upload allowance. Confirm the actual limit and available space in the service or device you plan to use.
The calculator can also clarify how technical choices affect storage. A longer render increases the estimate in direct proportion to its duration. A higher sample rate increases samples per second. Moving from 16-bit to 24-bit raises the modeled bytes per sample from two to three. A multichannel render stores more samples per moment than a stereo file.
- Compare stereo and mono versions of a mix.
- Estimate the scale of a surround render before export.
- Plan storage for alternate sample rates or bit depths.
- Estimate the combined PCM data for several renders by calculating each one and adding the results.
When estimating a batch, remember that this tool calculates one file at a time. Add the displayed estimates for the files you expect to keep. If the exports have different durations or formats, calculate each with its own settings rather than applying one estimate to the whole batch.
Other factors to consider when calculating export size
Export format is the biggest boundary of this model. PCM file size follows a predictable relationship to duration, sample rate, bit depth, and channels. Compressed audio does not follow this formula. For a constant-bitrate compressed file, duration and bitrate are useful for a rough estimate, but variable bitrate and encoder details can change the result.
Also consider the exact render length. Reverb tails, count-ins, printed effects, and silence can add time. If you export multiple stems, each stem may have its own channel count, and the total can be much larger than the stereo mix. A mono stem generally takes less sample data than a stereo stem of the same duration and settings, but the count of files matters too.
Finally, distinguish decimal gigabytes from binary gibibytes. Storage manufacturers commonly label capacity in decimal GB, while some operating systems display a binary-based figure or use different labels. Small differences between the calculator and a system display may come from that unit convention, rounding, or file overhead. Use the rendered file's properties as the final measurement.
Frequently asked questions
Does the calculator estimate MP3 or AAC size?
No. It estimates uncompressed PCM sample data. Compressed formats use encoding settings and signal-dependent behavior, so this formula would not faithfully predict their size. For those formats, use the encoder's bitrate and duration information or render a short representative test.
Why does a 24-bit export take more space than a 16-bit export?
The model assigns three bytes to each 24-bit sample and two bytes to each 16-bit sample. With duration, sample rate, and channel count held constant, the 24-bit data estimate is one and a half times the 16-bit estimate.
Should I select the number of tracks in my session?
No. Choose the channel count of the file being exported. A stereo mix has two output channels regardless of how many tracks feed the mix bus. For a stem or surround deliverable, select the channels in that particular rendered file.
Why is the actual file size slightly different?
The estimate excludes headers, metadata, and container details, and the displayed value is rounded. The operating system may also present storage using binary units. Check the finished file's properties when you need its exact size.
Can I estimate a set of several exports?
Yes. Calculate each export with its own duration, sample rate, bit depth, and channel count, then add the estimates. This gives a planning total for the uncompressed audio data, with the same exclusions for overhead and format-specific details.