Depends on the type of test. Most common test is an exercise treadmill test. This takes about 15 minutes of preparation. Then the test is started at a slope and speed which are increased every three minutes. Most people do 9:00 to 12 minutes. Some shorter and others longer.

Add 5:00 minutes of recovery and that is your time commitment. Tests with imaging would take longer. A nuclear stress test could take as long as three hours (mostly waiting between the stress and rest scans)

Depend on what king of stress test it is. Treadmill stress test can take up to an hour. A stress test that combine treadmill and imaging (nuclear or echocardiography) can take longer 1:30-2 hours