NCH Software Home
Home | Download | Support | Products | SiteMap

File size limitations

What's the maximum duration of a dictation?

The maximum size of an audio file depends on several limitations.

File system limitations

Maximum file size

Hard drives (or hard-drive partitions) are formatted using one of several file system types. The maximum size of a file depends on which file system is in use.

File system Maximum file size
FAT16 Approx. 2GB
FAT32 Approx. 4GB
NTFS Approx. 16TB

The file system of a drive can be found in Windows by right-clicking on the drive in Windows Explorer and selecting Properties. Please consider the file system of this software's working folder, as well as the file systems of any network shared folders that are being used.

Audio file size

This software stores audio internally using 16-bit uncompressed PCM WAV files. The number of bytes per second needed to store one of these audio recordings depends on the sample rate (also known as frequency) and the number of channels.

Sample rate Bytes per second per channel
8KHz 16,000
16KHz 32,000
22KHz 44,100
44KHz 88,200

Maximum audio duration

To calculate the longest amount of audio that honours the maximum file size:

Maximum file size in bytes / (Bytes per second per channel * Number of channels) = Maximum number of seconds


2,147,483,648 / (88,200 * 2) = 12,173
The longest stereo 44KHz recording that will fit on a FAT16 file system is approximately 12,173 seconds (~3.3 hours).

4,294,967,296 / (44,100 * 4) = 24,347
The longest 4 channel 22KHz recording that will fit on a FAT32 file system is approximately 24,347 seconds (~6.7 hours).

Software limitations

This software is limited to a maximum of 2,147,483,647 samples per audio file. At a sample rate of 44KHz, that gives approximately 13.5 hours of audio.

Other considerations

Meta-data (such as dictation notes) and attachments that are stored in the same file as the audio, as is the case with the DCT file format, will increase the total size of a file.


Back to Express Dictate Digital Dictation Software Technical Support

Try Express Dictate Digital Dictation Software
Download Express Dictate Digital Dictation Software free. Seeing and using the software first hand can answer most questions

Download Now

Top Product Categories

Sound Recording Software
Audio Software
Dictation Software
Video Software

Most Popular Programs

WavePad Sound Editor
Switch Sound File Converter
Express Burn Disc Burning Software
Prism Video File Converter
RecordPad Sound Recorder

Top | Back to Express Dictate Digital Dictation Software | Privacy | Legal | Home
© NCH Software