Storage Calculator
Session size from sample rate, bit depth, channel count and duration. For planning field recording, multitrack sessions and broadcast capture.
Session
Duration
Recording time by capacity
At the settings above, using 90% of each card or drive to leave filesystem overhead.
Figures are in decimal GB and MB, matching the units on storage media packaging. An OS or DAW reporting binary GiB will show slightly smaller numbers.
Recording time by channel count
At 48 kHz / 24-bit, for the storage and format selected here.
Audio Recording Storage Explained
The Formula
File Size (bytes) = Sample Rate × Bit Depth / 8 × Channels × Duration (seconds)
Example: 48,000 × 24 / 8 × 2 × 3,600 = 1,036,800,000 bytes ≈ 1037 MB/hour stereoCommon Scenarios
| Scenario | Settings | 1 Hour Stereo | 1 Hour 8-Channel |
|---|---|---|---|
| CD Quality | 44.1 kHz / 16-bit | ~635 MB | ~2.54 GB |
| Video/Broadcast Standard | 48 kHz / 24-bit | ~1037 MB | ~4.15 GB |
| High-Res Music | 96 kHz / 24-bit | ~2.1 GB | ~8.3 GB |
| Field Recorder (MP3 320) | 48 kHz / 320 kbps | ~144 MB | N/A |
Dante 64-ch stream at 48 kHz / 24-bit: ~33.2 GB/hour (decimal) or ~30.9 GiB/hour (binary), raw PCM data. Add ~5% for Ethernet overhead.
Format Notes
- WAV / BWF: Uncompressed PCM. Broadcast Wave Format adds metadata (timecode, originator). Use for archival.
- AIFF: Uncompressed PCM, cross-platform (EA IFF 85 standard). Identical size to WAV. Preferred in Logic Pro / macOS workflows.
- FLAC / ALAC: Lossless compression (~50–70% of WAV size for typical program material; can range as low as ~30% for very compressible content or up to ~75% for dense/noisy program). FLAC universal; ALAC for Apple ecosystems. Decode to identical PCM.
- MP3: Lossy. 320 kbps = transparent for most; 128 kbps = speech/podcast only. Not for multitrack.
- 32-bit float: Files are 33% larger than 24-bit, but allow gain adjustment post-recording without clipping.
Storage Media Overview
- NVMe SSD (USB 3.2/4, Thunderbolt): 256 GB–8 TB. Best for field multitrack: silent, fast, no moving parts.
- Portable HDD: 2 TB–8 TB. Cost effective for archival / less critical sessions. Verify write speed ≥ 100 MB/s.
- SD Cards: Common for field recorders. Audio requires very little bandwidth compared to video; a standard Class 10 or V30 card easily handles 24+ tracks of 24-bit/48kHz audio.
- Test before gig: Fill storage, verify sustained write speed, check for bad blocks.
Frequently Asked Questions
Why is my actual file size different from the calculation?
WAV headers add ~44 bytes. BWF adds more metadata. Some recorders pad to block boundaries. The formula gives raw PCM data size; actual files are ~0.01% larger. For MP3, VBR (variable bit rate) varies by content complexity.
Should I record 32-bit float?
32-bit float files are 33% larger than 24-bit but capture everything from silence to clipping without setting gain. Ideal for unpredictable sources (film dialog, nature, live sound where you can't soundcheck). If you can set gain properly, 24-bit is fine and saves space.
What's the difference between BWF and WAV?
BWF (Broadcast Wave Format) = WAV + standardized metadata chunk (originator, originator reference, date, timecode, coding history). All professional recorders write BWF by default. The .wav extension is used for both. BWF is backward compatible with standard WAV players.
How do I calculate for multitrack with different track lengths?
Calculate each track separately (channels = 1), then sum the file sizes. This tool assumes all channels record the same duration.
Does sample rate affect MP3 file size?
No. MP3 file size depends only on bit rate (kbps) and duration. 320 kbps MP3 at 44.1 kHz = same size as 320 kbps at 48 kHz. MP3 supports 44.1 kHz, 48 kHz and 32 kHz natively. For sample rates above 48 kHz, encoders typically downsample to a supported rate.