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About this tool
Work out uncompressed audio file size and data rate from duration, sample rate, bit depth and channels, with codec comparisons.
An audio file size calculator multiplies sample rate by bit depth by channel count to get the data rate, then multiplies that by duration to give the exact size of an uncompressed PCM file. It is aimed at engineers, podcasters and archivists sizing cards, drives and uploads, and it adds the 44-byte canonical WAV header so the number matches what actually lands on disk. The same duration is then priced in FLAC, MP3, AAC and Opus using the constant-bitrate rule bytes = kbps × 1000 ÷ 8 × seconds.
Open Audio File Size Calculator on AltFTool — it loads instantly in your browser.
Upload or drag in the file you want to work with.
Adjust the settings and preview the result.
Download the finished file to your device.
Uncompressed sizes are deterministic, so the byte count is the real one.
See the same recording at seven common delivery bitrates side by side.
Flags the 4 GB RIFF/WAVE ceiling before a long take truncates.
Multiply sample rate × bit depth × channels to get bits per second, divide by 8 for bytes per second, then multiply by the duration in seconds. CD audio is 44,100 × 16 × 2 = 1,411,200 bits per second, which is 176,400 bytes per second, or about 10.6 MB per minute.
About 17.3 MB per minute — 48,000 × 3 bytes × 2 channels = 288,000 bytes per second, which is 17.28 MB every 60 seconds. An hour of it comes to roughly 1.04 GB before any container overhead.
The RIFF header stores the file size in an unsigned 32-bit field, so a standard WAV cannot exceed 4,294,967,295 bytes — around 6.75 hours of 48 kHz 24-bit stereo. Recorders get past it by switching to RF64, Wave64 (.w64) or CAF, or by splitting the take across files.
No. FLAC is lossless, so its size depends on the material — quiet, sparse recordings compress far more than dense, loud masters. Sixteen-bit stereo music typically lands between 50% and 70% of the PCM size, which is why the FLAC row here is an adjustable estimate rather than a fixed answer.
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