Answer by Marius for Finding Android SDK on Mac and adding to PATH

Find the Android SDK location

Android Studio 
  > Preferences
  > Appearance & Behaviour
  > System Settings 
  > Android SDK
  > Android SDK Location

Create a .bash_profile file for your environment variables

• Open the Terminal app
• Go to your home directory via cd ~
• Create the file with touch .bash_profile

Add the PATH variable to your .bash_profile

• Open the file via open .bash_profile

• Add export PATH=$PATH: [your SDK location] /platform-tools to the file and hit ⌘s to save it. By default it's:

  export PATH=$PATH:/Users/yourUserName/Library/Android/sdk/platform-tools

• Go back to your Terminal App and load the variable with source ~/.bash_profile