The default zoom level in Google Chrome browser is set to 100%. But if you browse lot of web pages which requires increase in zoom settings then you change default zoom level using the Google Chrome Options.
Click the wrench icon available on Google Chrome and select Options from the menu list.
In the Options screen, navigate to Under the Hood section.
Then navigate to the Web Content section and using the Page zoom drop down you can set the default value more than 100%
On clicking the Page zoom drop down box the following list of values will be displayed, now select your desired value. By this way we can change the default zoom level using the Chrome browser settings.