Google chrome by default update itself automatically and you can also disable automatic google chrome update, but still if its not updating at your computer then you can also check for updates manually. Google chrome allows you to update it manually very simply in just some clicks.
Here is how you can update google chrome manually, as described below.
1. Open Google chrome and go to Options >> About Google Chrome
as shown in the image below
2. This will open a small message prompt, which allows you check to latest version and you can update google chrome version or it will also tell you which version of google chrome you are using.