Audio File Size Calculator

Uncompressed audio is the simplest data there is. A sound is measured a fixed number of times per second, each measurement is stored with a fixed number of bits, and every channel has its own list. So the size of a recording follows from four numbers, with no dependence on what it contains: a minute of silence takes as much as a minute of orchestra. This calculator multiplies them for you and compares the result with a compressed copy.

The formula

Bytes = sample rate × (bit depth ÷ 8) × channels × seconds, plus 44 bytes for the WAV header. The data rate in kilobits per second is sample rate × bit depth × channels ÷ 1,000. CD audio, 44,100 samples per second at 16 bits in two channels, has a data rate of 1,411.2 kbps. Studio recordings often use 48,000 Hz and 24 bits, which is 2,304 kbps for stereo.

A worked example

Press Sample: 44,100 Hz, 16 bits, stereo, 3 minutes 30 seconds, compared with a 192 kbps compressed file. The big number reads 37.0 MB (35.33 MiB), because 210 seconds × 176,400 bytes per second = 37,044,000 bytes plus the 44-byte header. The panel shows the data rate of 1,411.2 kbps, 10.6 MB per minute and 635 MB per hour. A 192 kbps copy takes 5.04 MB, which is 13.6% of the WAV.

How each setting changes the size

Doubling the sample rate doubles the size. Going from 16 to 24 bits multiplies it by 1.5, and to 32-bit float by 2. Stereo is twice mono; a 5.1 mix has six channels, three times stereo. Practical choices follow: speech recorded in mono at 24,000 or 22,050 Hz is small, while a multitrack session records every mono track at 48 kHz and 24 bits at about 8.6 MB a minute, so 24 tracks fill roughly 207 MB a minute.

What the numbers mean for sound

The sample rate sets the highest frequency that can be stored, half the rate: 44,100 Hz covers up to 22,050 Hz, above what most people hear. Bit depth sets the dynamic range, about 6 dB per bit: 16 bits give 96 dB, 24 bits 144 dB. Higher values mainly give headroom for editing; for a finished file played at home, 16 bits and 44.1 or 48 kHz is enough.

Edge cases

A WAV file’s header limits it to about 4 GiB; RF64 and similar formats lift that limit. The calculation assumes uncompressed integer or float samples: FLAC typically halves the size of the same audio without loss, and the comparison box is for lossy formats like MP3, AAC and Opus. Multi-channel counts include every channel, such as the low-frequency channel of 5.1.

Limits

The page performs arithmetic on the values you enter. It does not read a file or estimate the size of a compressed format from content: compressed sizes use the constant bitrate you type, so variable-bitrate files vary around it. No data leaves your device.

Planning storage for a project

The formula scales to whole sessions. One hour of stereo at 48,000 Hz and 24 bits is 48,000 × 3 bytes × 2 channels × 3,600 seconds, which is 1,036,800,000 bytes, or about 1.04 GB. A single mono track of the same quality is half of that, 518.4 MB an hour, so eight mono tracks recorded for three hours need about 12.4 GB before any takes are duplicated. Enter the channel count of your interface and the length of the longest session to see whether a drive has room.

Related tools

• Audio Converter writes the WAV, Opus or AAC file whose size you have estimated.
• Video File Size Calculator does the same arithmetic for video.
• Voice Recorder records the audio you are planning for.
• LUFS Loudness Meter measures the loudness of the finished file.