According to Glass.com, you should replace your windshield when: The glass is tempered, not laminated. The crack is longer than a dollar bill. The crack or chip is deep enough that it went more than halfway into the windshield.

When should I replace my windscreen?

If the driver's vision is impaired due to a chip or crack in their eyeline, the damage may be repaired if the diameter does not exceed 10mm. If the damage is more than 10mm, the entire windscreen will need to be replaced.

When should I be worried about a cracked windshield?

It is best to replace the windshield when the damage is larger than three inches, and there are more than three cracks or chips. Also, if the break is located at the edge of the windshield, jeopardizing its integrity and has “spider-webbed” quickly, then it is time to go to the repair shop.