Guides · updated October 22, 2026

WAV vs MP3 file size

How big a WAV really is, how small an MP3 gets at 128, 192 and 320 kbps, and how to estimate a conversion before you start.

Tested: 22 October 2026 · 16/44.1, 24/96 and 32-bit float WAV fixtures · measured output sizes

Short answer

A CD-quality WAV (44.1 kHz, 16-bit, stereo) is about 10.6 MB per minute. MP3 at 192 kbps is about 1.44 MB per minute, and at 320 kbps about 2.4 MB per minute. The WAV is roughly 4–7 times larger depending on the MP3 bitrate.

The WAV formula

PCM WAV stores every sample. The size is:

sample rate × channels × (bit depth ÷ 8) × seconds

For one minute of CD-quality stereo:

44,100 × 2 × 2 × 60 = 10,584,000 bytes

That is 10.6 MB (decimal) or 10.1 MiB (binary). The difference between MB and MiB is why two calculators can disagree by 5%.

Common WAV sizes per minute:

Format	Bytes per second	Per minute
44.1 kHz, 16-bit, stereo	176,400	10.6 MB
48 kHz, 16-bit, stereo	192,000	11.5 MB
48 kHz, 24-bit, stereo	288,000	17.3 MB
96 kHz, 24-bit, stereo	576,000	34.6 MB
48 kHz, 32-bit float, stereo	384,000	23.0 MB

The MP3 formula

MP3 is a constant bitrate stream (in this converter):

bitrate × seconds ÷ 8

For one minute:

Bitrate	Per minute	Per hour
128 kbps	0.96 MB	57.6 MB
192 kbps	1.44 MB	86.4 MB
256 kbps	1.92 MB	115.2 MB
320 kbps	2.4 MB	144 MB

Add a small amount for frame headers, ID3 tags and the Xing header. The measured output is usually within a few percent of the formula.

The ratio

For CD-quality WAV to MP3:

MP3 bitrate	WAV ÷ MP3
128 kbps	~11× smaller
192 kbps	~7.3× smaller
320 kbps	~4.4× smaller

For 24-bit/96 kHz WAV to 320 kbps MP3, the ratio is about 14×. That is a real saving, but it is also a real reduction in information. The WAV is the master; the MP3 is the copy you carry.

Estimate before you convert

Check the WAV duration.
Multiply by the per-minute figure for your source format.
Compare with the MP3 figure for the bitrate you want.
If the MP3 is still too large, lower the bitrate or trim the audio.

The converter shows the source size, duration and output size after conversion, so you can check the estimate against the real file.

What size does not tell you

A larger MP3 is not automatically better. A 320 kbps MP3 from a 96 kbps source is still a low-detail signal in a big container.
A smaller WAV is not automatically worse. A 16-bit/44.1 kHz WAV can be a better master than a 24-bit/96 kHz file with noise and clipping.
The container is not the quality. The source, the capture chain and the encoder settings decide what is preserved.

Use the formula to plan storage, not to rank audio quality.

FAQ

How do I calculate a WAV file size?

sample rate × channels × bit depth ÷ 8 × duration. For 44.1 kHz, stereo, 16-bit, one minute: 44,100 × 2 × 2 × 60 = 10,584,000 bytes, about 10.6 MB or 10.1 MiB.

How do I calculate an MP3 file size?

bitrate × duration ÷ 8. For 192 kbps and one minute: 192,000 × 60 ÷ 8 = 1,440,000 bytes, about 1.44 MB. Add a small amount for frame headers and the Xing tag.

Why is a 24-bit/96 kHz WAV so much larger?

It has 1.5× the bytes per sample (24 vs 16 bits) and 2.18× the sample rate (96 vs 44.1 kHz), so it is about 3.3× larger than CD-quality WAV: roughly 34.6 MB per minute for stereo.

Does a smaller MP3 always mean lower quality?

At the same source and codec, a lower bitrate usually means more loss. But a 128 kbps mono speech file can be perfectly clear, while a 320 kbps MP3 from a 96 kbps source is still limited by the source. Size is not a quality measurement by itself.

Can I make an MP3 smaller than 128 kbps?

Yes, but the useful range depends on the content. 64–96 kbps mono is common for speech; music at 64 kbps is noticeably degraded. MP3 also supports lower rates, but the encoder and player must agree on them.