How Much Lemon Concentrate Equals One Lemon?
One tablespoon of lemon concentrate is equal to one medium-sized lemon.
3 tbs equals 1 medium sized lemon.source: http://wiki.answers.com/Q/How_much_lemon_juice_concentrate_is_equivalent_to_one_lemon
It will all depend on the size of the lemon, for they all differ in size. It is said that three to four tablespoons of lemon concentrates is equivalent to a medium sized lemon.