Audio Bitrate Calculator
How big will a 2-hour podcast be at 128 kbps? Which bitrate keeps a song under 8 MB? How many kbps is a 24-bit/96 kHz WAV? Get the answers instantly — or drop a file to read its real bitrate.
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- Check real files
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Check a real file
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| Bitrate | File size | Per minute |
|---|
How to calculate audio file size
Pick what you want to calculate.
- 1
Choose a calculation
File size, bitrate, duration or uncompressed (PCM).
- 2
Enter the values
Type a bitrate, a duration or a size — or drop a file to fill them in.
- 3
Read the result
The result updates as you type, with a table for all common bitrates.
Every audio size question answered
Accurate formulas, clear units.
File size
Bitrate × duration ÷ 8, shown in MB and MiB.
Bitrate for a limit
The highest bitrate (and the nearest standard one) that fits a size limit.
Playing time
How many minutes of audio fit in a given size.
Uncompressed audio
WAV / PCM bitrate from sample rate, bit depth and channels.
Comparison table
Sizes for 32 to 320 kbps at your duration.
Real files
Read the actual bitrate, mode (CBR/VBR) and duration of a file.
Private
Files you check are read locally.
Free
No sign-up.
The audio bitrate formula
File size = bitrate × duration ÷ 8. A 128 kbps MP3 uses 128,000 bits per second = 16,000 bytes per second, so one minute takes 0.96 MB and an hour 57.6 MB. Tags and cover art add a little on top.
Uncompressed audio (WAV, AIFF, PCM) has a bitrate of sample rate × bit depth × channels: CD quality is 44,100 × 16 × 2 = 1,411.2 kbps (about 10.1 MB per minute); 24-bit / 96 kHz stereo is 4,608 kbps.
Storage is often shown in two ways: MB (1,000,000 bytes, used by macOS and drive makers) and MiB (1,048,576 bytes, used by Windows). The calculator shows both.
Common bitrates
| Format | Bitrate | Size per minute |
|---|---|---|
| MP3 voice | 64 kbps | 0.48 MB |
| MP3 standard | 128 kbps | 0.96 MB |
| MP3 / AAC high | 256 kbps | 1.92 MB |
| MP3 maximum | 320 kbps | 2.4 MB |
| CD / WAV 16-bit | 1,411 kbps | 10.6 MB |
| WAV 24-bit / 96 kHz | 4,608 kbps | 34.6 MB |
Tips
- Compress audio to a size limit automatically with the MP3 Compressor (Target size mode).
- Get the duration of many files at once with the Audio Duration Calculator.
- Shrink WAV files with the WAV Compressor.
- See all technical details of a file in the Audio Metadata Viewer.
Frequently asked questions
Can’t find your answer? Contact us — we reply quickly.
How do I calculate the size of an MP3?
Multiply the bitrate (kbps) by the duration in seconds and divide by 8 to get kilobytes: 128 kbps × 240 s ÷ 8 = 3,840 KB ≈ 3.8 MB.
What bitrate do I need for a file under 10 MB?
Divide the size in bits by the duration: 10 MB × 8,000 ÷ 300 s ≈ 266 kbps for a 5-minute song. Use the “Bitrate” tab to calculate it.
What is the bitrate of a WAV file?
Sample rate × bit depth × channels. CD-quality WAV is 1,411 kbps; 24-bit / 48 kHz stereo is 2,304 kbps.
Why is my real file a bit larger?
Tags, album art and container overhead add some kilobytes; VBR files also vary around their average bitrate.
MB or MiB?
1 MB = 1,000,000 bytes, 1 MiB = 1,048,576 bytes. Windows shows MiB but labels them “MB”.
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