Audio File Size & Bitrate Calculator
Work out audio file size from duration: WAV/PCM from sample rate, bit depth and channels, or MP3/AAC/Opus from the bitrate — or find the bitrate of a file from its size.
| Format | kbit/s | Size |
|---|---|---|
| PCM 16-bit / 44.1 kHz stereo (CD) | 1,411.2 | 37.04 MB |
| PCM 24-bit / 48 kHz stereo | 2,304 | 60.48 MB |
| PCM 24-bit / 96 kHz stereo | 4,608 | 120.96 MB |
| MP3 128 kbit/s | 128 | 3.36 MB |
| MP3 192 kbit/s | 192 | 5.04 MB |
| MP3 320 kbit/s | 320 | 8.4 MB |
| AAC 256 kbit/s | 256 | 6.72 MB |
| Opus 96 kbit/s | 96 | 2.52 MB |
| Phone-quality PCM 8 kHz 8-bit mono | 64 | 1.68 MB |
Audio file size depends on one number — the bitrate — multiplied by the duration. For uncompressed WAV or AIFF the bitrate follows directly from the sample rate, bit depth and number of channels. MP3, AAC and Opus encoders target a bitrate you choose. This calculator does both, lists the same recording in common formats side by side, and works backwards from a file's size and length to its average bitrate.
How to use this tool
- Choose what to calculate: uncompressed size, compressed size or bitrate.
- Enter the duration as seconds, m:ss or h:mm:ss.
- For uncompressed audio pick the sample rate, bit depth, channels and file type; for compressed audio enter the bitrate.
- To find a bitrate, enter the file size and its unit instead.
Formula
PCM bytes = sample rate × (bit depth ÷ 8) × channels × seconds (+ header); compressed bytes = kbit/s × 1000 × seconds ÷ 8
A basic WAV header is 44 bytes and an AIFF header 54 bytes. Sizes are shown in MB (10⁶ bytes, as storage makers and most players use) with MiB (2²⁰ bytes, as Windows reports) alongside. Bitrate in kbit/s = sample rate × bit depth × channels ÷ 1000 for PCM.
Example
One minute of CD-quality stereo (44.1 kHz, 16-bit) is 44,100 × 2 × 2 × 60 = 10,584,000 bytes, so the WAV file is 10,584,044 bytes (10.58 MB, 10.09 MiB) at 1,411.2 kbit/s. A 4-minute song as a 320 kbit/s MP3 is 320,000 × 240 ÷ 8 = 9.6 MB — about one-sixth of the WAV.
Frequently asked questions
How big is a FLAC file?
FLAC is lossless but its compression depends on the music: quiet acoustic recordings shrink more than dense, loud mixes. Many albums land somewhere around half to two-thirds of the WAV size; use the bitrate mode on a real file to see its rate.
Why does my file show 10.09 MB instead of 10.58 MB?
Windows divides by 1,048,576 (MiB) but labels the result MB. Both numbers describe the same file; this calculator shows both.
Does 24-bit audio sound better than 16-bit?
It gives more headroom for recording and editing. For finished music, 16-bit already covers about 96 dB of dynamic range, which exceeds most listening conditions, while 24-bit files are 50% larger.
Last updated:
Page address with these inputs: https://kakao.mobile/tools/audio-file-size-tool/
Cite or embed this tool
kakaoCalc. (2026, November 8). Audio File Size & Bitrate Calculator. https://kakao.mobile/tools/audio-file-size-tool/
“Audio File Size & Bitrate Calculator.” kakaoCalc, 8 Nov. 2026, kakao.mobile/tools/audio-file-size-tool/.
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