仕組み
WAV bytes = seconds × sample rate × (bit depth ÷ 8) × channels.
Compressed formats are estimated as a fraction of WAV — MP3 ≈ 8%, OGG ≈ 7%, Opus ≈ 5%.
Use the estimate to budget your final build size before encoding.
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Indie Game Audio File Size Estimator
インディーゲーム向けの無料オーディオサイズ推定機。
使うべき場面
Use during pre-production to budget your final build size. Indie mobile games and itch.io uploads have hard size limits.
他の指標との比較
Audacity and other DAWs report file size after encoding. This tool estimates before.
Enter your values below. Calculations run locally as you type.
よくある質問
When should I use OGG?
For looping music and ambience. OGG handles seamless loops better than MP3 at similar bitrates.
Is 22 kHz too low?
Acceptable for retro / SFX, but speech and music sound noticeably duller. 44.1 kHz is the safe default.
How is uncompressed WAV size calculated?
Multiply sample rate by bit depth by number of channels by seconds, then divide by 8 to get bytes. For example, stereo 44.1 kHz 16-bit audio is about 10.1 MB per minute.
Should music and voice use the same settings?
Not usually. Music benefits from a full 44.1 kHz sample rate to preserve high frequencies, while voice often sounds fine at 22 kHz mono, which roughly halves the file size.
実例
入力
30 minutes, OGG, 44.1 kHz, 16-bit, stereo.
出力
~22 MB total (~0.7 MB/minute).
WAV would be 30 × 60 × 44100 × 2 × 2 = ~317 MB. OGG ratio ~7% → ~22 MB.
よくある落とし穴
- OGG/MP3 ratios depend heavily on bitrate — defaults are for 192 kbps.
- Repeated SFX in many channels stack; budget per unique asset.
- 24-bit audio is rarely necessary in games — drop to 16-bit unless you have a strong reason.