Audio File Size & Bitrate Calculator
Calculate the uncompressed or compressed file size of an audio recording in megabytes. Use it when budgeting storage for sessions, streaming platforms, or archiving multi-track projects at different quality settings.
About this calculator
Digital audio file size depends on how many samples are captured per second, how many bits describe each sample, how many channels are recorded, and how much the data is compressed. The formula is: file size (MB) = (duration × sampleRate × bitDepth × channels / compressionRatio) / 8,388,608. The divisor 8,388,608 converts bits to megabytes (1 MB = 8 × 1,048,576 bits). A standard CD uses 44,100 Hz sample rate, 16-bit depth, and 2 channels — yielding roughly 10 MB per minute uncompressed. Professional 24-bit/96 kHz stereo audio triples that figure. Lossy formats like MP3 apply high compression ratios (8–11×) to reduce file size at the cost of some audio detail, while lossless formats like FLAC use moderate compression without discarding any data.
How to use
Suppose you record a 3-minute (180-second) stereo podcast at CD quality: sampleRate = 44,100 Hz, bitDepth = 16, channels = 2, compression = 1 (uncompressed WAV). Apply the formula: size = (180 × 44,100 × 16 × 2 / 1) / 8,388,608 = 254,016,000 / 8,388,608 ≈ 30.3 MB. If you export to MP3 with a compression ratio of 11, size = 30.3 / 11 ≈ 2.75 MB — a dramatic reduction suitable for web streaming while maintaining acceptable quality for speech content.
Frequently asked questions
What sample rate and bit depth should I use for professional audio recording?
For professional music production, 24-bit depth at 48 kHz or 96 kHz is the industry standard, providing sufficient headroom to avoid clipping during recording and enough frequency resolution for high-quality processing. CD masters are typically down-sampled to 16-bit/44.1 kHz for distribution. The human ear cannot perceive frequencies above about 20 kHz, so 96 kHz primarily benefits processing quality rather than final playback, but the larger files are worth it during the production stage.
How does compression ratio affect audio file size and quality?
A compression ratio of 1 means no compression — the file stores every sample exactly as recorded (WAV, AIFF). Lossless codecs like FLAC achieve ratios of roughly 2:1 without losing any audio data. Lossy codecs like MP3 or AAC reach ratios of 8:1 to 12:1 by permanently discarding audio information deemed less perceptible, which reduces file size dramatically but degrades quality at low bitrates. For archiving masters, always use uncompressed or lossless formats.
How much storage do I need for a multi-track recording session?
A 10-track recording session at 24-bit/48 kHz produces about 8.6 MB per track per minute, so a 30-minute session generates roughly 2.6 GB of raw audio — not counting takes, edits, and plugin renders. At 96 kHz the figure doubles to around 5 GB. SSDs rated at 500 GB are comfortable for short sessions, but professional studios with 32+ channels recording simultaneously should plan for several terabytes per project. Always budget at least 20% extra headroom for safety backups.