Audio File Size Estimator
Estimate the file size of uncompressed PCM audio from sample rate, bit depth, channel count, and duration. Pure math — no upload, no FFmpeg, instant result.
Result
Bytes per second
172.27 KB
Estimated WAV/PCM size
Includes 44-byte WAV header.
40.37 MB
Per-minute size
10.09 MB
Lossless PCM size = sample rate × (bit depth ÷ 8) × channels × seconds. CD-quality stereo (44.1 kHz, 16-bit, 2 ch) is ~10 MB/min.
About Audio File Size Estimator
Estimate the file size of uncompressed PCM audio from sample rate, bit depth, channel count, and duration. Pure math — no upload, no FFmpeg, instant result.
This calculator runs entirely in your browser using plain JavaScript math — no server round-trip and no upload. Inputs and results stay on your device. Closing or refreshing the tab discards everything immediately.
Related tools
About Audio File Size Estimator
Audio File Size Estimator is shaped around how people actually use audio editing and conversion utilities online: open the page, drop in a file, get the result. Estimate the file size of uncompressed PCM audio from sample rate, bit depth, channel count, and duration. Pure math — no upload, no FFmpeg, instant result. The interface stays out of the way once the work begins so the engine can use the available CPU and memory for the actual transformation.
Audio File Size Estimator sees the most use from students preparing oral submissions and voice-over artists exporting takes, but the design is intentionally generic enough that you do not need a specialist background to get a good result. The defaults aim at the most common case so a first-time user can get the right output without changing any settings.
Audio File Size Estimator works well as a bookmarked utility you reach for when you need it. The first visit shows you what the tool does; the second is when you realise it is a low-friction option for the task and worth keeping in your tab list.
The engine behind the page is standard browser APIs. It reads your file in-memory and writes the result back into the browser. Supported inputs include MP3, WAV, M4A, AAC, OGG, Opus, FLAC, AIFF, and WMA. For 200 MB and below the work usually completes in seconds; larger files mostly depend on how much spare RAM your device has.
Audio File Size Estimator is structured so the question "where is my file processed?" has a single answer: in your browser tab. The engine, the controls, and the result panel are all on one page. Navigating away or closing the tab clears the page's memory the way it does for every other tab.
For multi-step jobs, Audio File Size Estimator sits next to Audio File Size Calculator, Audio Bitrate Calculator, and Audio Duration Calculator. None of them depend on each other — you can use Audio File Size Estimator on its own — but together they cover the common variations of the task this page exists to handle.
The 200 MB ceiling on input size is the only fixed limit. Output files are produced in standard formats that every common viewer recognises, and the tool runs the same way regardless of how many times you have used it during the session.
Audio File Size Estimator keeps the control set focused. Every option on the page is there because a real workflow needs it, and the defaults aim at the most common case so a first-time user can get the right output without changing any settings.
Output handling is intentionally boring: Audio File Size Estimator produces `{name}-edited.{ext}` and triggers your browser's standard "save" behaviour. If you have a default download folder configured, that is where it will land. There is no Favtoo-side history of jobs you have run.
Audio File Size Estimator is structured around the idea that a useful tool should be its own page. Open the page, do the work, close the tab — the page is the entire product. There is no onboarding flow because there is nothing to onboard into.
Audio File Size Estimator runs as a regular web page, so there is no install step or permission grant before the first run. The page can be audited by viewing the source or by watching the developer-tools Network tab while a job runs.
Pro tip: Audio File Size Estimator works just as well in a private/incognito window as in a normal one, which is occasionally useful when you want zero browser-history footprint of the job. Another tip: if the tool ever feels slow, it is almost always because the browser tab is competing for CPU with another tab — pausing or closing the heavy ones gives the engine room to work.
Common gotchas worth flagging: Audio File Size Estimator only accepts MP3, WAV, M4A, AAC, OGG, Opus, FLAC, AIFF, and WMA, so if your file is in another format you will need to convert it first. The 200 MB ceiling is per-file, not per-session; you can run as many separate jobs as you like, but a single oversized input will be rejected on load.
That is the whole tool. Use Audio File Size Estimator for as long as it stays useful to you, and if it does, the catalog has many more tools built the same way. Each applies the same single-purpose discipline, so the way you used this page transfers to the next one you try.
How it works
- 1Open Audio File Size Estimator in your browser. The page loads quickly and the tool is ready to use the moment it becomes interactive.
- 2Select the MP3, WAV, M4A, AAC, OGG, Opus, FLAC, AIFF, and WMA file you want to process — drag-and-drop and the file picker both work.
- 3Pick any non-default settings you need. Most users leave the defaults alone for the first run and only revisit if the result needs tuning.
- 4Trigger processing. standard browser APIs reads your input, applies the transformation, and writes the result back into the page.
- 5Save the output (`{name}-edited.{ext}`) when it is ready.
- 6Repeat the process for additional inputs whenever you need to. The page stays loaded, so subsequent runs are quick.
Common use cases
- Compress a music demo small enough to share over messaging using Audio File Size Estimator.
- Extract the audio from a video so it can be edited separately.
- Re-encode a lossless track into a portable format for the gym.
- Convert a voice memo into a format your editor can open.
- Convert a band's rough mix into a format mastering software accepts.
- Boost a quiet interview recording to a normal listening level.
- Record a quick test tone to verify a microphone setup.
- Trim the cough out of the first ten seconds of a podcast take.
- Split a long mixtape into individual track files.
FAQ
What does this estimator calculate?
It computes the size of an uncompressed PCM WAV file using the formula: bytes = sampleRate × (bitDepth ÷ 8) × channels × durationSec. The result is shown in MB for easy reading. This is the actual storage required for raw audio with no compression.
Why estimate file size before recording?
To plan storage, pick the right format, or check whether your project will fit on a SD card / USB stick / disk partition. A multi-track session at 96 kHz / 24-bit can easily exceed 1 GB per hour per channel — knowing this in advance lets you adjust quality settings before you record hours of audio.
What sample rate and bit depth should I use?
For voice/podcast: 44.1 kHz, 16-bit, mono is plenty (~5 MB/minute). For music recording: 48 kHz, 24-bit, stereo (~17 MB/minute). For high-end mastering: 96 kHz, 24-bit (~33 MB/minute). For archival: 96 kHz, 32-bit float, but float is for processing not storage.
How do compressed formats compare?
A 1-minute uncompressed WAV at 44.1/16/stereo is ~10 MB. The same audio as MP3 at 320 kbps is ~2.4 MB. As MP3 at 128 kbps it's ~1 MB. As FLAC (lossless) it's ~5–7 MB depending on content. As Opus 96 kbps it's ~720 KB. Use this estimator for the WAV reference; compressed sizes vary.
Why is this tool not slower in the browser?
Unlike audio transcoding, this is pure arithmetic — there's no FFmpeg WebAssembly involved. Results are instant and identical to any server-side tool. The "in-browser is slower" caveat only applies to actual audio processing.
Can I estimate compressed file sizes too?
For compressed formats, use the Audio File Size Calculator with your target bitrate (kbps) instead of bit depth. This Estimator is specifically for uncompressed PCM where the size is fully determined by the sample format.
Why is in-browser audio processing slower than online tools?
Server-side tools use multi-threaded native FFmpeg running on dedicated CPUs with fast disks and parallel pipelines. Our engine is FFmpeg compiled to WebAssembly, which runs single-threaded inside your browser tab and has no access to native hardware acceleration. That makes browser-based jobs typically 3–8× slower than a server. The trade-off is total privacy: your audio file is never uploaded, never logged, and never stored — closing the tab erases everything from memory immediately. For most clips up to a few minutes the wait is small, and for sensitive recordings (voice memos, drafts, confidential meetings) the privacy gain is well worth it.
Is my audio uploaded?
No. Everything runs entirely inside your browser tab using FFmpeg compiled to WebAssembly. The file is read into local memory only, processed in the same tab, and the result is offered as a direct download. Nothing is transmitted to any server, no account is required, no analytics are tied to your file, and closing the tab discards every byte from memory.
How big a file can I process?
The file picker accepts audio inputs up to about 1 GB, which is well above what mainstream "free tier" online converters allow. The real ceiling is your device — everything runs inside your browser tab, which shares memory with the rest of the page. Most podcasts, songs, and voice memos sit comfortably under that limit even on a phone. If a very large lossless WAV or FLAC ever fails, trim it first or transcode to MP3 / Opus to bring the size down before re-running the tool.
Which audio formats are supported?
MP3, WAV, OGG (Vorbis and Opus), FLAC, M4A (AAC), AAC, Opus, AIFF, and WMA all decode reliably via FFmpeg WASM. Output formats depend on the specific tool — most editing tools default to MP3 (universal) or WAV (lossless) but expose a format picker so you can pick the one that fits your downstream player or DAW.
Which browsers are supported?
Recent Chrome, Edge, Firefox, Safari, and other Chromium-based browsers all work. The tool relies on WebAssembly and SharedArrayBuffer, which require the page to be served over HTTPS with the right cross-origin headers — this site is configured correctly by default. On phones the same code runs but is slower than on a desktop because mobile CPUs are weaker.
Is there a watermark, sign-up wall, or usage cap?
No. The tool is completely free, requires no account, attaches no watermark, applies no usage caps, and shows no popup ads on your output. Because the work happens on your own device, there is no per-user quota for us to enforce — your hardware and browser memory are the only limits. The download is the file you would get from running FFmpeg locally, nothing more, nothing less.
Will Audio File Size Estimator keep working if my Wi-Fi drops mid-task?
Once the page is loaded, Audio File Size Estimator can complete jobs without an active internet connection — the engine is bundled with the page, so there is no per-job network call. The initial page load does require a connection (to fetch the static assets), but after that you can disconnect entirely and the tool will still work. This is a side-effect of the local-first architecture, not a deliberate "offline mode" feature.
Does Audio File Size Estimator work on a phone or tablet?
Audio File Size Estimator runs in any modern mobile browser — Safari, Chrome, Firefox and the in-app browsers in most messaging apps all support the underlying APIs. Performance depends on the device: a recent phone handles typical inputs nearly as fast as a laptop, while older devices may take a few seconds longer near the 200 MB ceiling. The interface lays out cleanly on small screens, so you do not need to pinch-zoom to see the controls.
Will I notice a difference in the output from Audio File Size Estimator?
Audio File Size Estimator is built to preserve quality wherever the underlying audio format allows it. Operations that are mathematically lossless (e.g. structural transformations, lossless re-encoding) round-trip with no perceptible change. Operations that involve a lossy codec inevitably introduce small artefacts at the byte level, but the defaults aim at the sweet spot where output looks or sounds the same to a normal viewer or listener while still being meaningfully smaller or faster than the input.
Is Audio File Size Estimator keyboard accessible?
Audio File Size Estimator uses native HTML controls wherever possible, which means keyboard navigation, focus rings, and screen-reader labels work the way the platform expects. The drop zone accepts files via the keyboard-accessible file picker as well as drag-and-drop, and result downloads use standard browser download flows. If you spot an accessibility gap, Favtoo treats it as a bug worth fixing.
Can I use Audio File Size Estimator for commercial work?
Audio File Size Estimator can be used for personal and commercial work alike — there is no separate "business" licence to purchase. The output you generate is yours to use however you want, including in client deliverables, internal documents, or commercial products. Favtoo's only ask is fair, individual use; the tool is not designed to be embedded as a backend service or wrapped behind an API for resale.
Will Audio File Size Estimator ask me to pay to download the result?
Audio File Size Estimator is free to use. The processing runs in your browser, which keeps the per-user cost low enough that the tool can be offered openly. The download is the same file the engine produced — you can use it for as many runs as you need.
Can I trust the output of Audio File Size Estimator for important work?
Audio File Size Estimator is built on standard browser APIs, which is the same class of engine used by professional audio editing and conversion pipelines. For deterministic operations, the output is byte-identical to what an equivalent CLI run would produce; for operations involving a codec or a model, the result is well within the range of what comparable tools generate. If you have a specific reference output you need to match, run a small test job first to confirm the configuration produces what you expect.