How much space does a 3-minute song use?

At 128 kbps MP3: ~2.8 MB. At 256 kbps AAC: ~5.6 MB. At 320 kbps MP3: ~7.0 MB. At CD quality WAV (1,411 kbps): ~31.8 MB. At FLAC (~800 kbps average): ~18 MB. The format and bitrate determine the tradeoff between size and quality.

What bitrate should I use for podcasts?

For speech-only podcasts: 64 kbps mono (mono is fine for speech). For interview/conversation: 96–128 kbps mono or stereo. For music-heavy podcasts: 128–192 kbps stereo. Higher bitrates provide negligible improvement for speech.

Is FLAC significantly smaller than WAV?

Yes. FLAC is lossless and typically 40–60% of WAV size (50–60% compression ratio). A 630 MB WAV album becomes 250–380 MB in FLAC with zero quality loss. FLAC is the standard for archival and audiophile libraries.

What is the best format for streaming?

AAC at 128–256 kbps offers the best quality-per-bit for music streaming. Opus at 64–128 kbps is excellent for voice and music. MP3 at 256–320 kbps has universal compatibility. Choose based on your target platform's codec support.

How do I calculate WAV file size?

WAV size = sample_rate × bit_depth × channels × duration_sec / 8. Standard CD: 44,100 Hz × 16 bits × 2 channels × 3600 sec / 8 = 635 MB/hour. High-res (96 kHz/24-bit): ~2,074 MB/hour.

Does mono vs stereo affect storage?

Stereo doubles the file size compared to mono at the same bitrate per channel. However, most encoded formats specify total bitrate (e.g., 128 kbps stereo means 64 kbps per channel). For speech content, mono saves 50% with no quality loss.

Audio Storage Estimator

Estimate audio storage from bitrate, duration, and format. Plan capacity for podcasts, music libraries, and voice recordings.

Bitrate

kbps

Duration

Duration Unit

Number of Tracks

Per Track

56.25 MB

3,600 sec

Total Storage

27.47 GB

500 track(s)

Per Minute

0.94 MB

Per Hour

56.25 MB

Planning notes, formulas, and examples

About the Audio Storage Estimator

Audio files vary dramatically in size depending on format, bitrate, and encoding. A one-hour podcast at 128 kbps MP3 is about 57 MB, while the same content in uncompressed WAV (16-bit, 44.1 kHz stereo) is over 635 MB—an 11× difference. For large audio libraries, streaming platforms, or podcast hosting services, accurate storage estimation is essential for budgeting and capacity planning.

This calculator estimates audio file size and total storage from bitrate (kbps), duration (in seconds, minutes, or hours), and track count. It covers common formats including MP3, AAC, OGG Vorbis, FLAC, WAV, and AIFF. You can model individual tracks or entire libraries with thousands of files.

Whether you're planning storage for a podcast hosting platform, a music streaming service, a call center voice archive, or a personal music collection, this estimator gives you quick, reliable storage estimates.

When This Page Helps

Audio libraries grow quickly. 10,000 songs at 10 MB each is 100 GB. A podcast network with 5,000 episodes at 60 MB each needs 300 GB. This calculator prevents storage shortfalls by projecting requirements accurately.

How to Use the Inputs

Enter the audio bitrate in kbps (e.g., 128, 256, 320 for MP3).
Enter the total duration to estimate.
Select the duration unit (seconds, minutes, or hours).
Optionally enter the number of tracks or files.
Review the per-track and total storage estimate.
Compare formats to find the best size/quality tradeoff.

Formula used

file_size_MB = bitrate_kbps × duration_sec / 8 / 1024; total = file_size × track_count

Example Calculation

Result: 56.25 MB/episode; 27.47 GB total

128 kbps × 3,600 sec / 8 / 1,024 = 56.25 MB per hour-long episode. 500 episodes = 28,125 MB = 27.47 GB. Upgrading to 256 kbps doubles size to ~55 GB. Consider whether listeners can perceive the quality difference.

Tips & Best Practices

For podcasts (speech), 64–128 kbps mono is sufficient—higher bitrates waste space on speech content.
For music, 256–320 kbps MP3 or 128–256 kbps AAC is transparent to most listeners.
FLAC is lossless and 40–60% the size of WAV—use it for archival storage.
Opus codec offers the best quality-per-bit for voice at low bitrates (32–64 kbps).
WAV is uncompressed—use for editing masters, not distribution or archival.
Always keep a lossless master; generate lossy formats for distribution.

Format Comparison

MP3: Universal support, 128–320 kbps, lossy. AAC: Better quality than MP3 at same bitrate, Apple/Android native. OGG Vorbis: Open source, good quality, limited hardware support. Opus: Best low-bitrate codec, excellent for voice and music. FLAC: Lossless, 500–1000 kbps effective, 40–60% of WAV. WAV: Uncompressed, 1,411 kbps for CD, editing standard.

Music Library Sizing

A 10,000-track library at 256 kbps AAC (~6 MB/track): ~60 GB. The same library in FLAC (~20 MB/track): ~200 GB. In WAV (~35 MB/track): ~350 GB. Choose based on whether you prioritize storage efficiency or lossless quality.

Podcast Hosting Considerations

Podcast hosting services charge by storage and bandwidth. A weekly 1-hour podcast at 128 kbps produces ~57 MB/episode and ~3 GB/year. A daily podcast produces ~21 GB/year. Factor in download bandwidth: 10,000 downloads/episode × 57 MB = 570 GB bandwidth per episode.

Sources & Methodology

Last updated: February 8, 2026

Frequently Asked Questions

At 128 kbps MP3: ~2.8 MB. At 256 kbps AAC: ~5.6 MB. At 320 kbps MP3: ~7.0 MB. At CD quality WAV (1,411 kbps): ~31.8 MB. At FLAC (~800 kbps average): ~18 MB. The format and bitrate determine the tradeoff between size and quality.