Gnometry - MP3 Resizing Assistant

Gnometry Utility

Gnometry is a utility you can use to calculate the target length of your MP3 files.

"Why would I ever want to resize an audio file," you ask? Here are a few scenarios where this might come in handy:

  1. You're preparing a radio ad, and have a great piece of music to accompany—but it's a few seconds too long (or too short).
  2. You're training for a race, and want to change the pace of your favorite music so that your stride keeps in step with the music.
  3. Your church choir members are trying to learn a new piece of music, but can't keep up with the speed of the rehearsal recording.

To download a fully-functional version of Gnometry, click the green button to the right, and enter your name and e-mail address. You'll receive an e-mail with download instructions. From there, just install Gnometry, and you'll be up and running in no time.

Installation couldn't be easier. Just download the installer and select a target install folder.

Main Page

Gnometry works alongside Audacity, a free and open-source digital audio editor you can download from here.

Audacity is an amazing tool which allows you to modify your favorite audio files. But if you've ever had to shrink or grow a music file, you'll find that it's not easy to estimate what percentage to specify.

The purpose of the form to the right is to allow you to specify the current length and beats-per-minute (BPM). Then, just specify the target BPM rate. Gnometry will calculate exactly how long the target file should be. Watch for an upcoming tutorial on


A built-in metronome provides audible clicks and visual cues—allowing you to test your source and target MP3 files, so you can be sure you know exactly how many beats per minute you're working with.

Tap The Tempo

When you don't know the current BPM tempo of a song, this utility can help. Just start playing the song, then repeatedly click the 'Tap the Tempo' button with your mouse (or spacebar), keeping time with the music. After a minimum of eight clicks, the BPM rate will appear to the right, as shown below.