How to find magento version?

There are two ways to see what version of magento you’re using.

Method 1:
Login to the admin for Magento:
http://www.yourdomain.com/admin/
...and look in the footer, you should see the following:

Magento ver. X.X.X

Where X.X.X is the version number.

Method 2:
If you only have access to the source code, Use the below code.

echo Mage::getVersion();

print_r(Mage::getVersionInfo());