Start the speed test by clicking on the big button in the center of the page. The check will start by downloading a file and will measure your download speed. Once the download has finished, the broadband speed test will try to upload a file and will measure your upload speed.
The broadband speed is measured in kbps (kilobits per second). Approximately 1000 Kbps is 1Mb/s.
If you want to get accurate results then you should not use your internet connection for any other applications once the speed checker is running.