Audio File Size Calculator

How it is calculated

Uncompressed audio stores every sample in full, so the size is a product: bytes = rate × (depth / 8) × channels × (minutes × 60). Here rate is the sample rate in Hz (samples per second per channel), depth is bits per sample, channels is 1 for mono and 2 for stereo, and minutes is the length. Dividing depth by 8 turns bits into bytes.

The byte total is shown two ways: in MB (divided by 1,000,000) and in MiB (divided by 1,048,576), which is the figure most operating systems report. The bit rate is rate × depth × channels / 1000 in kbps. All four inputs must be above zero. The result is the raw audio data only; file headers, metadata and any compression such as MP3 or FLAC are not included.

Common mistakes

• Entering the sample rate in kHz (44.1 or 48). The field is in Hz, so 48 means 48 samples per second and the size comes out around a thousand times too small.
• Comparing MB with the MiB or size your computer shows. The same file is about 5% larger in MB than in MiB, so check which unit you are reading.
• Forgetting the channel count. A stereo file is twice the size of mono at the same settings, and a surround recording is larger still.
• Entering the time in seconds. The duration field is minutes, so 90 seconds is 1.5.
• Expecting MP3, AAC or FLAC sizes. This is uncompressed PCM only; compressed formats are far smaller and depend on their own bit rate.