How music file size is calculated
A digital audio file's size depends on its bitrate – how many kilobits are used per second of sound – and its length. Uncompressed CD audio uses 1,411 kbps (16 bits × 44,100 samples × 2 channels). Lossless compression such as FLAC or ALAC shrinks that to roughly 700 – 1,000 kbps without losing any information, while lossy formats like MP3 and AAC discard data the ear is less sensitive to and use 128 – 320 kbps.
File size (MB) = minutes × 60 × bitrate (kbps) ÷ 8 ÷ 1000
Formats compared
| Format | Bitrate | 4-minute song | Songs per 64 GB |
|---|
| MP3 128 kbps | 128 kbps | 3.8 MB | ≈ 16,000 |
| AAC 256 / MP3 320 | 256 – 320 kbps | 7.7 – 9.6 MB | ≈ 6,500 – 8,000 |
| FLAC / ALAC 16/44.1 | ~900 kbps | ≈ 27 MB | ≈ 2,300 |
| WAV 16/44.1 | 1,411 kbps | 42 MB | ≈ 1,500 |
| FLAC 24/96 | ~2,800 kbps | ≈ 84 MB | ≈ 750 |
| FLAC 24/192 / DSD64 | ~5,500 kbps | ≈ 165 MB | ≈ 380 |
FLAC sizes vary with the music: quiet acoustic recordings compress more than dense rock or electronic music, so treat these as averages.
Choosing storage for a portable player or phone
- microSD cards: buy a card from a reputable brand rated A1/U3 or better; 256 – 512 GB cards hold large FLAC libraries.
- Digital audio players (DAPs): check the maximum supported card size and whether the player has two card slots.
- Phones: internal storage is shared with apps and photos – plan for the library plus at least 20 % free space.
- Home libraries: a NAS or external drive with a backup copy keeps years of collecting safe.
Streaming data usage
Streaming services use 96 – 320 kbps for lossy quality – about 40 – 145 MB per hour – while lossless CD quality uses around 600 MB per hour and hi-res 24-bit streams 1 – 2.5 GB per hour. On a limited mobile plan, download playlists over Wi-Fi or choose a lower quality on cellular.
Can you hear the difference?
In controlled blind tests, most listeners can't reliably tell well-encoded 256 – 320 kbps AAC or MP3 from lossless on typical headphones. Lossless formats still have advantages: they're future-proof, can be converted to any other format without loss, and remove any doubt. Hi-res files mainly benefit studio work and very high-end systems.
Frequently asked questions
How many songs fit in 1 GB?
About 260 songs as MP3 at 128 kbps, 100 – 130 at 256 – 320 kbps, and roughly 35 – 40 as CD-quality FLAC, for 4-minute songs.
How big is a FLAC file?
A typical 4-minute CD-quality FLAC file is about 20 – 35 MB; a 24-bit/96 kHz hi-res FLAC is roughly 70 – 100 MB.
What size SD card do I need for my music?
Calculate your library size, add expected growth and keep 20 % free. A 5,000-song FLAC library needs a 256 GB card.
How much data does music streaming use?
About 70 MB per hour at 160 kbps, 145 MB at 320 kbps, around 600 MB for lossless CD quality and over 1 GB for hi-res.
Is FLAC better than MP3?
FLAC is lossless – identical to the CD – while MP3 discards data. At high bitrates most people can't hear the difference, but FLAC is a better archive.
About TrackSpace
TrackSpace is an independent, free calculator for planning storage for music libraries on phones, digital audio players, SD cards and NAS drives, and for estimating streaming data use. File sizes use average bitrates; actual FLAC compression varies by recording. We are not affiliated with any streaming service or device maker.
Every formula on this page runs entirely in your web browser. The numbers you type are never uploaded, stored or shared. Our goal is simple: give you an honest starting point so you can compare product specifications with confidence and avoid paying for capacity you do not need – or buying something too small to do the job.
The methodology combines widely published engineering rules of thumb, manufacturer data sheets and the electrical code practices that installers use every day. We review the assumptions regularly and update the calculator when typical product specifications change.
Privacy Policy
Last updated: October 28, 2026
This Privacy Policy explains how TrackSpace ("we", "us") handles information when you visit this website. By using the site you agree to this policy.
Information we collect
We do not require registration and we do not ask for your name, address or payment details. Values entered into the calculator are processed locally in your browser and are not transmitted to our servers. Like most websites, our hosting provider may automatically record standard server log data such as IP address, browser type, referring page and time of visit for security and performance purposes.
Cookies and advertising
We use Google AdSense to show advertisements that keep this tool free. Third-party vendors, including Google, use cookies to serve ads based on a user's prior visits to this website or other websites. Google's use of advertising cookies enables it and its partners to serve ads to users based on their visit to this site and/or other sites on the Internet. You may opt out of personalized advertising by visiting Google Ads Settings, or opt out of some third-party vendors' use of cookies for personalized advertising at www.aboutads.info. To learn more, see How Google uses information from sites or apps that use its services.
Visitors from the European Economic Area, the United Kingdom and Switzerland are shown a consent message powered by a Google-certified consent management platform, where you can accept, reject or manage cookie choices. You can change your choices at any time from the privacy link displayed by that message. Some visitors may also be offered the option to view a short ad or complete another offer in exchange for access to the content; this choice is provided by Google and is entirely optional where alternatives are offered.
Analytics
We may use privacy-friendly, aggregated statistics to understand which features are used. These statistics do not identify you personally.
Your rights
Depending on where you live (for example under the GDPR or the CCPA/CPRA), you may have the right to access, correct or delete personal data and to object to certain processing. Because we do not keep personal data from the calculator, most requests can be handled by clearing cookies in your browser. For any other request, contact us at the address above.
Children
This site is intended for a general adult audience and is not directed at children under 13. We do not knowingly collect personal information from children.
Changes to this policy
We may update this policy from time to time. The date at the top of this section shows when it was last revised.
Terms of Use & Disclaimer
The calculator and articles on this website are provided free of charge for general information and educational purposes only. Results are estimates based on typical values and simplifying assumptions; real-world performance depends on the specific product, installation, climate, wiring and how you use your equipment.
Nothing on this site is professional engineering, electrical or financial advice. Always follow the manufacturer's instructions and local electrical codes, and have permanent installations, transfer switches and grid-connected systems designed and installed by a licensed electrician or qualified installer. Never operate fuel-burning generators indoors or in enclosed spaces – carbon monoxide can kill within minutes.
The site is provided "as is" without warranties of any kind. To the fullest extent permitted by law, TrackSpace is not liable for any loss or damage arising from the use of, or reliance on, the information or results provided. Product and brand names mentioned belong to their respective owners and are used for identification only. You may use the calculator for personal and commercial purposes, but you may not copy or republish the site content without permission.
TrackSpace