The lengths of the four types of madd

These are the lengths of the four types of madd:

• Madd al-badal is 2 harakah.
• Madd Munfassil is 4 or 5 harakah.
• Madd Muttassil is 4 or 5 harakah. 
• Madd Laazim 6 harakah not less.           

All these types of stretch are explained in details in their corresponding chapters