There are a few signs that you are outgrowing your web hosting plan. These signs include: slowness, random timeouts, and almost hitting your account limits. When your web hosting experience has any of these signs you may want to start looking into getting a new plan.
If your site experiences slowness during random times. This maybe an indication that either the web server you are on is overloaded or your are simply growing beyond your web hosting plan. If you are hosting a site that has thousands of pages and run into the thousands of visitors per month then its probably your account and not the web server.
If your site has less than 1,000 pages and only a minimum amount of traffic per month then the slowness maybe an indication of the server having too many customers.
If your PHP scripts are experiencing random timeouts then it will either be your server being overloaded or you are hitting your PHP memory limits. When you reach your PHP memory limits your scripts will not be able to function properly. When this happens you will start to notice a lot of errors in your server logs. These logs can also be viewed from within your control panel.
If you had these script timeouts when you first began using your web hosting plan then it may not be because of your account and maybe signs of an overloaded server.
Web hosting limits
When you are logged into your web hosting control panel and see that your limits for space or bandwidth is reaching near what your web hosting plan has allocated for you. If you are about to hit the limit for your disk space or bandwidth then this is one major sign that you are outgrowing your web hosting plan. In this case you will need to consider if you want to upgrade or move to another web host with more resources.