In simple words if you want to know how much radiation your phone is putting out, you need to figure out its SAR value. How to check your phone's SAR value? In order to measure the SAR value, one should look behind the packaging of their cell phone. Nowadays users can check the SAR value of their phone on their mobile phone's manufacturer's website as it is mandatory to mention the SAR value of mobile phones. Also, usually bigger brands tend to have phones with lower SAR value.

Source: India Today September 19, 2017 12:11 UTC