Audio File Size Calculator
Enter your recording duration, sample rate, bit depth and channel count to find the uncompressed file size (WAV, AIFF, FLAC). Add a lossy bitrate to see the compressed size (MP3, AAC, OGG) and compare both side by side. Results update as you type.
How audio file size is calculated
The size of an uncompressed audio file (WAV, AIFF, or the raw PCM stream inside FLAC) depends on four parameters: sample rate, bit depth, channel count, and duration. The formula is simple: multiply sample rate (Hz) by bit depth (bits) by the number of channels by the duration in seconds, then divide by 8 to convert bits to bytes. For example, one minute of CD-quality stereo audio is 44,100 samples/s x 16 bits x 2 channels x 60 s / 8 = 10,584,000 bytes, or about 10.6 MB. Compressed formats like MP3 and AAC discard perceptually irrelevant audio data using psychoacoustic models, so their size is simply bitrate (kbps) x duration in seconds / 8. A 128 kbps MP3 for the same one-minute clip is 128,000 bits/s x 60 / 8 = 960,000 bytes, or about 0.96 MB - roughly 11 times smaller.
Sample rate, bit depth and channels explained
Sample rate is how many audio snapshots are captured per second. The CD standard of 44,100 Hz was chosen because it exceeds twice the upper limit of human hearing (the Nyquist theorem requires sampling at more than twice the highest frequency you want to capture). Professional audio uses 48,000 Hz or 96,000 Hz. Bit depth controls the dynamic range: 16-bit gives 96 dB of range (sufficient for music playback), while 24-bit gives 144 dB (needed during recording to handle peaks without clipping). Channels multiply the data: stereo needs two independent streams, Dolby 5.1 needs six, and Dolby Atmos object audio can use many more. Every extra channel, higher sample rate, or deeper bit depth increases the uncompressed file size proportionally.
Lossy compression: MP3, AAC and OGG
Lossy codecs reduce file size by permanently discarding audio information that most listeners cannot hear, such as very quiet sounds that are masked by loud ones. The bitrate (measured in kilobits per second) controls how aggressively they compress. At 128 kbps, most listeners cannot distinguish an AAC file from a CD; at 64 kbps, compression artifacts become audible on music but are acceptable for speech. MP3 remains the most universally compatible format; AAC (used by Apple Music, YouTube and podcast apps) achieves similar quality at a lower bitrate; OGG Vorbis (used by Spotify) is an open-source alternative with good quality at mid-range bitrates. FLAC is lossless compression: it reduces the file by 40-60% compared with WAV while recovering every original bit, making it ideal for archiving.
Choosing the right format and bitrate
For archiving and editing, always use uncompressed WAV or AIFF (or lossless FLAC) to preserve full quality. For streaming and podcast distribution, 128-192 kbps AAC or MP3 is the standard range. Podcast voice-only content sounds fine at 64-96 kbps mono, which keeps download sizes small. For music, 192-320 kbps MP3 or 256 kbps AAC covers most listeners. Storage cost matters too: a 90-minute concert at 24-bit/96 kHz stereo WAV is about 2.4 GB; the same session as a 320 kbps MP3 is just 216 MB. Use the chart above to see how size grows with duration across your chosen formats.
Common audio format file sizes (3 minutes, stereo)
| Format | Bitrate | File size (approx.) | Typical use |
|---|---|---|---|
| MP3 | 64 kbps | 1.4 MB | Podcasts, voice |
| MP3 | 128 kbps | 2.8 MB | Music streaming (standard) |
| MP3 | 192 kbps | 4.2 MB | Music streaming (high) |
| MP3 | 320 kbps | 7.0 MB | Music (maximum quality) |
| AAC | 128 kbps | 2.8 MB | Apple Music, YouTube |
| AAC | 256 kbps | 5.5 MB | Apple Music lossless |
| OGG Vorbis | 160 kbps | 3.5 MB | Spotify Desktop |
| WAV (16-bit/44.1 kHz) | 1,411 kbps | 30.9 MB | CD quality uncompressed |
| WAV (24-bit/48 kHz) | 2,304 kbps | 50.4 MB | Professional studio |
| WAV (32-bit/96 kHz) | 6,144 kbps | 134.2 MB | High-res mastering |
| FLAC (16-bit/44.1 kHz) | ~700 kbps | ~15 MB | Lossless compressed |
Approximate file sizes for a 3-minute stereo recording at each standard format and quality setting.
Frequently asked questions
What is the file size of a 3-minute MP3?
It depends on the bitrate. At 128 kbps (a common default), a 3-minute MP3 is about 2.8 MB. At 320 kbps (the maximum standard bitrate), it is about 7.0 MB. Use the calculator above and set the lossy bitrate to your chosen setting to get an exact figure.
How large is a WAV file compared to an MP3?
A CD-quality WAV file (44,100 Hz, 16-bit, stereo) is about 10.6 MB per minute. A 128 kbps MP3 of the same clip is about 0.96 MB per minute - roughly 11 times smaller. The WAV preserves every sample exactly; the MP3 discards inaudible data to achieve the smaller size.
Does stereo audio take exactly twice the space of mono?
Yes, for uncompressed audio. Stereo stores two independent sample streams, so it is exactly twice the data of mono at the same sample rate and bit depth. For lossy formats like MP3, the encoder can use joint stereo, which shares some data between channels, so the size ratio is not always exactly 2:1 - but a rough doubling is a safe estimate.
What sample rate and bit depth should I use for recording?
For music production and most professional recording, 24-bit at 48,000 Hz is the standard: it provides 144 dB of dynamic range, more than enough headroom to capture peaks cleanly, and the extra headroom disappears when you dither down to 16-bit for distribution. 96,000 Hz is used for film and high-resolution audio, but the larger file sizes are only meaningful if your mastering workflow needs extreme EQ or time-stretching headroom.
How many songs fit on a 1 GB storage card?
It depends heavily on the format. At 128 kbps MP3, a 3-minute song is about 2.8 MB, so 1 GB holds roughly 350 songs. At CD-quality WAV (10.6 MB per minute), a 3-minute song is about 31.8 MB, so 1 GB holds only about 31 songs. Use the calculator to enter your specific format, then divide 1,000 MB (1 GB) by the file size per song.