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Audio File Size Estimator

Math

Estimate an audio file's size before you record or export it: uncompressed PCM size from sample rate, bit depth, and channel count, or compressed size from a target bitrate

Work out how big an audio file will be before you record or export it, instead of finding out after disk fills up. Pick uncompressed mode to get the exact PCM size from sample rate, bit depth, and channel count the way a WAV recording would produce it, or compressed mode to get the size a target bitrate works out to for an MP3, AAC, or Opus export. It is pure arithmetic over the numbers you give it: nothing is recorded, encoded, or uploaded, so it can't tell you the real size of an existing file, only what a given combination of settings adds up to.

audiofilesizecalculatorwavpcmbitrate

How to use Audio File Size Estimator

  • 1.Pick uncompressed (WAV/PCM) or compressed (bitrate) mode depending on what you're estimating.
  • 2.Enter the duration plus sample rate, bit depth, and channel count, or a target bitrate.
  • 3.Read the estimated file size in both decimal MB and binary MiB.

Frequently asked questions

Why is the uncompressed estimate bigger than I expected?
Uncompressed PCM audio doesn't use any psychoacoustic compression, so a few minutes of 48kHz/24-bit stereo audio easily runs into the tens of megabytes. That is the actual cost of recording lossless, not a bug in the estimate.
What does the 44-byte header account for?
That is the canonical WAV file's RIFF/fmt/data chunk header size. Other containers like AIFF use a slightly different header, so treat this as a close estimate for WAV specifically, not every uncompressed container.
Can this tell me the real size of an audio file I already have?
No, this is a pure calculator over numbers you type in. For an existing file's actual size and format details, use the WAV Audio Info or ID3 Tag Reader tools instead.
Does it account for MP3/AAC frame or container overhead?
No, the compressed-mode formula is exactly bitrate times duration divided by 8. Frame headers and container overhead are typically a small fraction of the payload for anything longer than a few seconds, so this is a close estimate, not an exact prediction.

Use via API, SDK, or MCP

cURL# Free: 1,000 req/day · Pro: 10,000 req/day
curl -X POST https://api.utilix.tech/v1/tools/audio-file-size-estimator \
  -H "Authorization: Bearer utx_live_..." \
  -H "Content-Type: application/json" \
  -d '{"mode":"pcm","durationSeconds":60,"sampleRateHz":44100,"bitDepth":16,"channels":2,"bitrateKbps":192}'

Get an API key from your dashboard · Full API docs →

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