7 July 2026 | 5 min read
WAV file size: the simple formula, and how much a shoot day really weighs
One multiplication tells you how much card, drive and backup you need. Here it is, with the numbers a production day actually produces.
Uncompressed WAV size is entirely predictable, because nothing is being compressed away. The formula is one line: sample rate multiplied by bit depth, multiplied by number of channels, multiplied by duration in seconds, divided by eight to get bytes.
The reference numbers
- 48 kHz, 24 bit, mono: about 8.6 MB per minute.
- 48 kHz, 24 bit, stereo: about 17.3 MB per minute.
- 48 kHz, 24 bit, 8 channel poly: about 69 MB per minute.
- 96 kHz, 24 bit, stereo: about 34.6 MB per minute.
- 48 kHz, 32 bit float, 8 channel poly: about 92 MB per minute.
What a shoot day looks like
Take an eight track poly recording at 48 kHz, 24 bit. Ten hours of rolling would be 41 GB, but nobody rolls continuously. A realistic dialogue day records between 90 minutes and 3 hours of actual takes, which is 6 to 12 GB. Add wild tracks and room tone and call it 15 GB per day.
Why the 4 GB limit still bites
A classic WAV file uses 32 bit size fields, so it cannot exceed 4 GB. Recorders handle this by splitting long takes into consecutive files, or by writing RF64, an extension that supports larger sizes. RF64 files are valid WAVs to most modern software, but older tools may refuse them.
Planning cards and backups
The standard rule is three copies on two types of media with one off site. That triples your storage figure, so a 15 GB day is really 45 GB of managed storage. For long form projects, keeping FLAC archives of the original poly masters cuts that by roughly half with no quality loss.
If you need to check what a file actually contains before doing the maths, drop it into the inspector: sample rate, bit depth, channel count and duration are read locally in your browser.