Add 4 cups of water and all of the sugar to a medium saucepan. Place the pan over medium heat, and whisk occasionally until the sugar is completely dissolved.
All the simple syrup to cool to room temperature.
Pour the simple syrup, lemon juice, and remaining 4 cups of water into a large pitcher. Stir to combine. Store in the fridge until ready to drink.
To serve, pour the lemonade into glasses filled with ice.
Notes
This lemonade is a little on the sweet side. You can reduce the amount of sugar to 2 tablespoons if desired. My kids like their lemonade sweeter and my mom likes it more tart, to each their own.
You'll need 2-3 lemons per 1/3 cup of juice. A total of 16-24 lemons are needed per pitcher.