About this tool
Estimate how big an audio recording will be, or how long one will fit on a card, entirely in your browser. It covers uncompressed PCM/WAV using sample rate, bit depth and channels, and compressed formats like MP3, AAC or FLAC using a fixed bitrate. Enter a duration to get the file size, or a card size to get the maximum recording time. Nothing is uploaded.
For uncompressed audio the size in bytes is sample rate × (bit depth ÷ 8) × channels × seconds. For compressed audio it is bitrate (kbps) × 1000 × seconds ÷ 8. The data rate is the bytes-per-second value scaled to kbps, and the maximum recording time is the target card size divided by that byte rate. Sizes are shown in binary units, so 1 MB is 1,048,576 bytes.
As a check, CD-quality stereo — 44,100 Hz, 16-bit, 2 channels — for 60 seconds is about 10.09 MB at a 1,411 kbps data rate. Use this to plan session storage, pick a bitrate for a target size, or see how many minutes a recorder will capture before its card fills up.