Audio File Size Calculator
Knowing the file size of an audio recording before you capture or export it helps you plan storage requirements, budget for streaming bandwidth, and choose between formats intelligently. Audio file size is determined by the format, the sample rate, the bit depth, the number of channels, and the duration. WAV files store uncompressed pulse-code modulation (PCM) audio: every sample is stored exactly as captured, with no compression applied. The file size is entirely determined by the product of sample rate, bit depth, channel count, and duration. FLAC uses lossless compression to reduce WAV file sizes by approximately 40%, preserving every bit of audio data while saving storage space. MP3 and AAC are lossy formats that apply psychoacoustic compression algorithms to discard audio information that is less perceptible to human listeners, achieving much smaller file sizes at the cost of some audio fidelity. Choosing between these formats involves a trade-off between audio quality, file size, and compatibility with your playback devices. Enter the format parameters below and the calculator returns both the file size in megabytes and in kilobytes.
How audio file size is calculated
For uncompressed formats (WAV), file size is the direct product of sample rate, bit depth, channel count, and duration. FLAC applies lossless compression: this calculator estimates FLAC at 60% of the equivalent WAV size. For lossy formats (MP3 and AAC), file size is determined solely by the bitrate and duration.
WAV bytes = sample_rate * (bit_depth / 8) * channels * total_seconds
FLAC bytes = WAV bytes * 0.60
MP3 / AAC bytes = (bitrate_kbps * 1,000 / 8) * total_seconds
File size (MB) = bytes / 1,000,000
File size (KB) = bytes / 1,000
Worked example: WAV stereo at 44,100 Hz, 16-bit, 3 minutes 30 seconds
- Total seconds = 3 * 60 + 30 = 210 seconds
- Bytes = 44,100 * (16 / 8) * 2 * 210 = 44,100 * 2 * 2 * 210 = 37,044,000 bytes
- File size = 37,044,000 / 1,000,000 = 37.04 MB
Worked example: MP3 at 320 kbps, 3 minutes 30 seconds
- Total seconds = 210 seconds
- Bytes = (320 * 1,000 / 8) * 210 = 40,000 * 210 = 8,400,000 bytes
- File size = 8,400,000 / 1,000,000 = 8.40 MB
Audio file size: frequently asked questions
What is the difference between lossless and lossy audio formats?
Lossless formats (WAV and FLAC) store every sample of the original audio signal without discarding any data. WAV stores uncompressed PCM audio; FLAC applies lossless compression that typically reduces file size by around 40% without any loss of audio information. Lossy formats (MP3 and AAC) apply psychoacoustic compression, permanently discarding audio data that is less audible to most listeners. Lossy files are much smaller but cannot be restored to exact original quality.
How does sample rate affect audio file size?
Sample rate is the number of times per second the audio waveform is measured. At 44,100 Hz (CD quality), 44,100 samples are captured per second per channel. Doubling the sample rate to 96,000 Hz produces files that are roughly 2.2 times larger. For stereo WAV at 44,100 Hz and 16-bit: 44,100 * 2 * 2 bytes = 176,400 bytes per second, or about 10.1 MB per minute. At 96,000 Hz and 24-bit: 96,000 * 3 * 2 bytes = 576,000 bytes per second, or about 32.9 MB per minute.
What is a typical FLAC compression ratio?
FLAC typically achieves a compression ratio of around 50 to 70% of the original WAV file size, meaning a 100 MB WAV file becomes approximately 50 to 70 MB as FLAC. The ratio depends on the audio content: music with lots of silence, repetition, or simple tones compresses better than complex, loud music with dense layering. This calculator uses 60% of the uncompressed WAV size as a representative estimate for FLAC.
How do streaming services compare to download sizes?
Streaming services typically use lossy compression to minimise bandwidth. Spotify streams at up to 320 kbps MP3 or Ogg Vorbis, which is about 2.4 MB per minute. Apple Music uses AAC at 256 kbps for standard streams (about 1.9 MB per minute) and lossless ALAC for higher-quality streams. Tidal HiFi streams FLAC at 1,411 kbps for CD quality, around 10.6 MB per minute. Downloaded files for offline use are stored at whatever bitrate the service uses for that tier.
Does higher bit depth make a noticeable difference in audio quality?
Bit depth determines the dynamic range of the recording. 16-bit audio provides 96 dB of dynamic range, which exceeds the typical listening environment. 24-bit provides 144 dB of dynamic range, which is useful during recording and mixing to provide headroom and reduce quantisation noise. For final delivery and listening, the difference between 16-bit and 24-bit is debated among audiophiles, but the scientific consensus is that 16-bit CD quality is sufficient for most human listeners at normal listening levels.
Sources and methodology
- EBU R68 broadcast audio standard: tech.ebu.ch.
- Audio format specifications: WAV/PCM format per IEEE 802, FLAC format specification at xiph.org.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology. FLAC size is an estimate based on a 60% compression ratio; actual results vary with audio content.