In a medium pot, combine sugar and 2 cups water over low heat and stir until the sugar is completely dissolved to create a simple syrup. Remove from heat.
While the simple syrup is cooling, squeeze the lemons to make 2 cups of juice. Pour the juice through a fine mesh strainer over a 2 quart pitcher.
Add the simple syrup, ice and 4 cups water. Stir.
Slice any extra lemons and stir them in.
Chill until ready to use or drink right away! Enjoy!