Help with screen/font size zoom

Every now and then my macbook pro zooms to a smaller % view when I do something with the trackpad by accident and I don't know how to get it back. When it happens in Word I just change the % back to 100% at the top, but it just happened with google chrome and now my gmail page is a bit too small to read! What is the trackpad shortcut to change it back to normal size? I can't find this :-(

NB this is not a question about zooming in using ctrl + scrolling up and down with 2 fingers.

Many thanks.

You can also zoom by using the two finger pinch trackpad gesture which is probably what you are doing. Just go to your system preferences and in the trackpad section you will see a demonstration of how it's done. If you do the gesture by accident a lot and it bothers you then just turn it off. You can also go back to normal size view by going to the view menu in most applications and then choose actual view.