Generally speaking, the display on Windows 10 computer will automatically turn off when the screen is left idle for ten minutes. If it is longer or shorter than your expected time limit, you can go to choose when to turn off display, referring to the two methods below.
Video guide on how to customize when to turn off display in Windows 10:
Way 1: Choose when to turn off display in PC settings.
Step 1: Access PC settings.
Step 2: Open PC and devices (or System).
Step 3: Choose Power and sleep.
Step 4: Choose time on the right.
FYI, you can select time from 1 minute, 2 minutes, 3 minutes, 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes and 30 minutes.
Way 2: Choose when to turn off display in Control Panel.
Step 1: Open Control Panel.
Step 2: Enter System and Security.
Step 3: Tap Change when the computer sleeps under Power Options.
Step 4: Click the down arrow and select time from the list.
Step 5: Click Save changes to make the setting effective.