One medium-sized lemon has 2 to 3 tablespoons of juice in it. The amount of juice in a lemon depends on several factors, including storage and ripeness of the lemon.
A lemon stored at room temperature yields more juice. If the lemon is cold, it tends to yield less juice. When a lemon is stored at room temperature, simplify the juicing process by pressing and rolling the lemon around on a counter-top or flat surface.
Slice the lemon in half, then press the lemon to squeeze the juice out of it by cupping it in your hand and applying force to the lemon. You can also use a standard lemon and lime juicer. When squeezing the juice out with your hand, cup your other hand underneath to catch the seeds.