When you export a trimmed clip, the format choice decides how big the file is, where it will play and whether it can be edited again without losing quality. Most decisions come down to a handful of formats.
Lossy vs lossless
Lossless formats (WAV, AIFF, FLAC, ALAC) keep every sample exactly. WAV stores them uncompressed; FLAC packs them like a ZIP file, typically to about half the size, and unpacks them perfectly.
Lossy formats (MP3, AAC/M4A, Ogg Vorbis, Opus) use psychoacoustic models to throw away sound you're unlikely to hear, such as quiet details masked by louder sounds at nearby frequencies. They are many times smaller. The amount discarded is controlled by the bitrate, in kilobits per second.
File size per minute
File size is simply bitrate × duration. For stereo audio:
| Format | Bitrate | Size per minute | 30-second ringtone |
|---|---|---|---|
| WAV 16-bit, 44.1 kHz | 1,411 kbps | 10.6 MB | 5.3 MB |
| FLAC | ~700–1,000 kbps | 5–7.5 MB | 2.5–3.8 MB |
| MP3 320 kbps | 320 kbps | 2.4 MB | 1.2 MB |
| MP3 192 kbps | 192 kbps | 1.44 MB | 0.72 MB |
| AAC (M4A/M4R) 192 kbps | 192 kbps | 1.44 MB | 0.72 MB |
| MP3 128 kbps | 128 kbps | 0.96 MB | 0.48 MB |
Use the audio file size calculator for any duration, bitrate or channel count.
The formats
MP3
The universal format. Every phone, car stereo, smart speaker, browser and editing app plays MP3. At 192 kbps and above it is transparent for most listeners. Its patents expired in 2017, so encoders such as LAME are freely available. Choose MP3 when the file will be shared or played on unknown devices, and for Android ringtones.
M4A (AAC)
M4A is an MPEG-4 container usually holding AAC audio — the successor to MP3 and the default for Apple devices, YouTube and many streaming services. AAC is more efficient than MP3: at the same bitrate it generally sounds a little better, which shows most at 128 kbps and below. iPhone Voice Memos and GarageBand use it. Older car stereos and some Windows tools are the main compatibility gaps.
M4R
M4R is not a separate codec. It is an M4A file with a different extension, which tells Finder and iTunes to treat it as an iPhone ringtone and sync it into Tones. Two rules apply: the audio must really be AAC (a renamed MP3 won't work), and ringtones synced this way can be at most 40 seconds long. With iOS 26 you can also set an MP3 or M4A under 30 seconds as a ringtone directly from the Files app — see how to make an iPhone ringtone.
WAV
WAV holds raw PCM audio — the format closest to what audio hardware actually plays. It's the standard working format for editing, video production, samplers and broadcast. Because nothing is discarded, you can edit and re-save a WAV forever without loss. The downside is size: ten times an MP3. Export WAV when you'll edit the clip further, or when a device or app specifically needs it.
FLAC
Lossless and compressed — the archive format for music collections. Android, Windows, macOS and recent iPhones play it, but many car systems and older devices don't. Convert to MP3 with the FLAC to MP3 converter for portable copies.
OGG (Vorbis and Opus)
Open, royalty-free lossy formats. Opus is the most efficient codec here and powers WhatsApp voice notes, Discord and WebRTC calls. Android uses OGG for many system sounds. Apple support is limited, so convert to MP3 or M4A for iPhone users with the OGG to MP3 converter.
Which format for which job?
| Job | Best format | Settings |
|---|---|---|
| iPhone ringtone (computer sync) | M4R | 192 kbps, ≤ 40 s |
| iPhone ringtone (iOS 26 Files) | M4A or MP3 | 192 kbps, < 30 s |
| Android ringtone or notification | MP3 | 192 kbps |
| Voice memo to share | MP3 | 128 kbps mono |
| Clip for a video editor | WAV | 16-bit, original sample rate |
| Music to keep | MP3 320 or AAC 256 | or keep the lossless original |
Sample rate and channels
CD audio and most music use a 44.1 kHz sample rate; video uses 48 kHz. Both capture everything humans can hear. Higher rates (96 kHz and up) matter in studios but not for ringtones. Mono (one channel) halves the size of uncompressed and low-bitrate files and is ideal for speech; phone speakers are often mono anyway.
Avoiding quality loss
Every time you decode and re-encode a lossy file, a little more is lost. Keep a lossless or high-bitrate original, do your edits, and encode the final lossy file once. When converting between lossy formats — M4A to MP3, for example — use a bitrate at least as high as the source. More on that in how to cut an MP3 precisely.